diff --git a/tools/aapt2/LoadedApk.cpp b/tools/aapt2/LoadedApk.cpp
index 9b9cde2..6b1fd9f 100644
--- a/tools/aapt2/LoadedApk.cpp
+++ b/tools/aapt2/LoadedApk.cpp
@@ -72,7 +72,7 @@
   }
 }
 
-std::unique_ptr<LoadedApk> LoadedApk::LoadApkFromPath(const StringPiece& path,
+std::unique_ptr<LoadedApk> LoadedApk::LoadApkFromPath(StringPiece path,
                                                       android::IDiagnostics* diag) {
   android::Source source(path);
   std::string error;
diff --git a/tools/aapt2/LoadedApk.h b/tools/aapt2/LoadedApk.h
index a4aff3f..4cd7eae 100644
--- a/tools/aapt2/LoadedApk.h
+++ b/tools/aapt2/LoadedApk.h
@@ -45,7 +45,7 @@
   virtual ~LoadedApk() = default;
 
   // Loads both binary and proto APKs from disk.
-  static std::unique_ptr<LoadedApk> LoadApkFromPath(const ::android::StringPiece& path,
+  static std::unique_ptr<LoadedApk> LoadApkFromPath(android::StringPiece path,
                                                     android::IDiagnostics* diag);
 
   // Loads a proto APK from the given file collection.
diff --git a/tools/aapt2/NameMangler.h b/tools/aapt2/NameMangler.h
index 0b49052..0b08c32 100644
--- a/tools/aapt2/NameMangler.h
+++ b/tools/aapt2/NameMangler.h
@@ -36,7 +36,7 @@
    * We must know which references to mangle, and which to keep (android vs.
    * com.android.support).
    */
-  std::set<std::string> packages_to_mangle;
+  std::set<std::string, std::less<>> packages_to_mangle;
 };
 
 class NameMangler {
@@ -54,7 +54,7 @@
                         mangled_entry_name);
   }
 
-  bool ShouldMangle(const std::string& package) const {
+  bool ShouldMangle(std::string_view package) const {
     if (package.empty() || policy_.target_package_name == package) {
       return false;
     }
@@ -68,8 +68,8 @@
    * The mangled name should contain symbols that are illegal to define in XML,
    * so that there will never be name mangling collisions.
    */
-  static std::string MangleEntry(const std::string& package, const std::string& name) {
-    return package + "$" + name;
+  static std::string MangleEntry(std::string_view package, std::string_view name) {
+    return (std::string(package) += '$') += name;
   }
 
   /**
diff --git a/tools/aapt2/Resource.cpp b/tools/aapt2/Resource.cpp
index df8c3b9..cfcb2bb 100644
--- a/tools/aapt2/Resource.cpp
+++ b/tools/aapt2/Resource.cpp
@@ -138,11 +138,11 @@
   return {to_string(t), t};
 }
 
-std::optional<ResourceNamedTypeRef> ParseResourceNamedType(const android::StringPiece& s) {
+std::optional<ResourceNamedTypeRef> ParseResourceNamedType(android::StringPiece s) {
   auto dot = std::find(s.begin(), s.end(), '.');
   const ResourceType* parsedType;
   if (dot != s.end() && dot != std::prev(s.end())) {
-    parsedType = ParseResourceType(s.substr(s.begin(), dot));
+    parsedType = ParseResourceType(android::StringPiece(s.begin(), dot - s.begin()));
   } else {
     parsedType = ParseResourceType(s);
   }
@@ -152,7 +152,7 @@
   return ResourceNamedTypeRef(s, *parsedType);
 }
 
-const ResourceType* ParseResourceType(const StringPiece& str) {
+const ResourceType* ParseResourceType(StringPiece str) {
   auto iter = sResourceTypeMap.find(str);
   if (iter == std::end(sResourceTypeMap)) {
     return nullptr;
diff --git a/tools/aapt2/Resource.h b/tools/aapt2/Resource.h
index 9cfaf47..7ba3277 100644
--- a/tools/aapt2/Resource.h
+++ b/tools/aapt2/Resource.h
@@ -74,7 +74,7 @@
 /**
  * Returns a pointer to a valid ResourceType, or nullptr if the string was invalid.
  */
-const ResourceType* ParseResourceType(const android::StringPiece& str);
+const ResourceType* ParseResourceType(android::StringPiece str);
 
 /**
  * Pair of type name as in ResourceTable and actual resource type.
@@ -87,7 +87,7 @@
   ResourceType type = ResourceType::kRaw;
 
   ResourceNamedType() = default;
-  ResourceNamedType(const android::StringPiece& n, ResourceType t);
+  ResourceNamedType(android::StringPiece n, ResourceType t);
 
   int compare(const ResourceNamedType& other) const;
 
@@ -108,19 +108,19 @@
   ResourceNamedTypeRef(const ResourceNamedTypeRef&) = default;
   ResourceNamedTypeRef(ResourceNamedTypeRef&&) = default;
   ResourceNamedTypeRef(const ResourceNamedType& rhs);  // NOLINT(google-explicit-constructor)
-  ResourceNamedTypeRef(const android::StringPiece& n, ResourceType t);
+  ResourceNamedTypeRef(android::StringPiece n, ResourceType t);
   ResourceNamedTypeRef& operator=(const ResourceNamedTypeRef& rhs) = default;
   ResourceNamedTypeRef& operator=(ResourceNamedTypeRef&& rhs) = default;
   ResourceNamedTypeRef& operator=(const ResourceNamedType& rhs);
 
   ResourceNamedType ToResourceNamedType() const;
 
-  std::string to_string() const;
+  std::string_view to_string() const;
 };
 
 ResourceNamedTypeRef ResourceNamedTypeWithDefaultName(ResourceType t);
 
-std::optional<ResourceNamedTypeRef> ParseResourceNamedType(const android::StringPiece& s);
+std::optional<ResourceNamedTypeRef> ParseResourceNamedType(android::StringPiece s);
 
 /**
  * A resource's name. This can uniquely identify
@@ -132,9 +132,8 @@
   std::string entry;
 
   ResourceName() = default;
-  ResourceName(const android::StringPiece& p, const ResourceNamedTypeRef& t,
-               const android::StringPiece& e);
-  ResourceName(const android::StringPiece& p, ResourceType t, const android::StringPiece& e);
+  ResourceName(android::StringPiece p, const ResourceNamedTypeRef& t, android::StringPiece e);
+  ResourceName(android::StringPiece p, ResourceType t, android::StringPiece e);
 
   int compare(const ResourceName& other) const;
 
@@ -157,9 +156,8 @@
   ResourceNameRef(const ResourceNameRef&) = default;
   ResourceNameRef(ResourceNameRef&&) = default;
   ResourceNameRef(const ResourceName& rhs);  // NOLINT(google-explicit-constructor)
-  ResourceNameRef(const android::StringPiece& p, const ResourceNamedTypeRef& t,
-                  const android::StringPiece& e);
-  ResourceNameRef(const android::StringPiece& p, ResourceType t, const android::StringPiece& e);
+  ResourceNameRef(android::StringPiece p, const ResourceNamedTypeRef& t, android::StringPiece e);
+  ResourceNameRef(android::StringPiece p, ResourceType t, android::StringPiece e);
   ResourceNameRef& operator=(const ResourceNameRef& rhs) = default;
   ResourceNameRef& operator=(ResourceNameRef&& rhs) = default;
   ResourceNameRef& operator=(const ResourceName& rhs);
@@ -346,8 +344,8 @@
 //
 // ResourceNamedType implementation.
 //
-inline ResourceNamedType::ResourceNamedType(const android::StringPiece& n, ResourceType t)
-    : name(n.to_string()), type(t) {
+inline ResourceNamedType::ResourceNamedType(android::StringPiece n, ResourceType t)
+    : name(n), type(t) {
 }
 
 inline int ResourceNamedType::compare(const ResourceNamedType& other) const {
@@ -380,7 +378,7 @@
 //
 // ResourceNamedTypeRef implementation.
 //
-inline ResourceNamedTypeRef::ResourceNamedTypeRef(const android::StringPiece& n, ResourceType t)
+inline ResourceNamedTypeRef::ResourceNamedTypeRef(android::StringPiece n, ResourceType t)
     : name(n), type(t) {
 }
 
@@ -398,8 +396,8 @@
   return ResourceNamedType(name, type);
 }
 
-inline std::string ResourceNamedTypeRef::to_string() const {
-  return name.to_string();
+inline std::string_view ResourceNamedTypeRef::to_string() const {
+  return name;
 }
 
 inline bool operator<(const ResourceNamedTypeRef& lhs, const ResourceNamedTypeRef& rhs) {
@@ -422,13 +420,12 @@
 // ResourceName implementation.
 //
 
-inline ResourceName::ResourceName(const android::StringPiece& p, const ResourceNamedTypeRef& t,
-                                  const android::StringPiece& e)
-    : package(p.to_string()), type(t.ToResourceNamedType()), entry(e.to_string()) {
+inline ResourceName::ResourceName(android::StringPiece p, const ResourceNamedTypeRef& t,
+                                  android::StringPiece e)
+    : package(p), type(t.ToResourceNamedType()), entry(e) {
 }
 
-inline ResourceName::ResourceName(const android::StringPiece& p, ResourceType t,
-                                  const android::StringPiece& e)
+inline ResourceName::ResourceName(android::StringPiece p, ResourceType t, android::StringPiece e)
     : ResourceName(p, ResourceNamedTypeWithDefaultName(t), e) {
 }
 
@@ -471,14 +468,13 @@
 inline ResourceNameRef::ResourceNameRef(const ResourceName& rhs)
     : package(rhs.package), type(rhs.type), entry(rhs.entry) {}
 
-inline ResourceNameRef::ResourceNameRef(const android::StringPiece& p,
-                                        const ResourceNamedTypeRef& t,
-                                        const android::StringPiece& e)
+inline ResourceNameRef::ResourceNameRef(android::StringPiece p, const ResourceNamedTypeRef& t,
+                                        android::StringPiece e)
     : package(p), type(t), entry(e) {
 }
 
-inline ResourceNameRef::ResourceNameRef(const android::StringPiece& p, ResourceType t,
-                                        const android::StringPiece& e)
+inline ResourceNameRef::ResourceNameRef(android::StringPiece p, ResourceType t,
+                                        android::StringPiece e)
     : ResourceNameRef(p, ResourceNamedTypeWithDefaultName(t), e) {
 }
 
diff --git a/tools/aapt2/ResourceParser.cpp b/tools/aapt2/ResourceParser.cpp
index 19fd306..fa9a98f 100644
--- a/tools/aapt2/ResourceParser.cpp
+++ b/tools/aapt2/ResourceParser.cpp
@@ -50,11 +50,11 @@
 constexpr const char* sXliffNamespaceUri = "urn:oasis:names:tc:xliff:document:1.2";
 
 // Returns true if the element is <skip> or <eat-comment> and can be safely ignored.
-static bool ShouldIgnoreElement(const StringPiece& ns, const StringPiece& name) {
+static bool ShouldIgnoreElement(StringPiece ns, StringPiece name) {
   return ns.empty() && (name == "skip" || name == "eat-comment");
 }
 
-static uint32_t ParseFormatTypeNoEnumsOrFlags(const StringPiece& piece) {
+static uint32_t ParseFormatTypeNoEnumsOrFlags(StringPiece piece) {
   if (piece == "reference") {
     return android::ResTable_map::TYPE_REFERENCE;
   } else if (piece == "string") {
@@ -75,7 +75,7 @@
   return 0;
 }
 
-static uint32_t ParseFormatType(const StringPiece& piece) {
+static uint32_t ParseFormatType(StringPiece piece) {
   if (piece == "enum") {
     return android::ResTable_map::TYPE_ENUM;
   } else if (piece == "flags") {
@@ -84,9 +84,9 @@
   return ParseFormatTypeNoEnumsOrFlags(piece);
 }
 
-static uint32_t ParseFormatAttribute(const StringPiece& str) {
+static uint32_t ParseFormatAttribute(StringPiece str) {
   uint32_t mask = 0;
-  for (const StringPiece& part : util::Tokenize(str, '|')) {
+  for (StringPiece part : util::Tokenize(str, '|')) {
     StringPiece trimmed_part = util::TrimWhitespace(part);
     uint32_t type = ParseFormatType(trimmed_part);
     if (type == 0) {
@@ -122,7 +122,7 @@
   StringPiece trimmed_comment = util::TrimWhitespace(res->comment);
   if (trimmed_comment.size() != res->comment.size()) {
     // Only if there was a change do we re-assign.
-    res->comment = trimmed_comment.to_string();
+    res->comment = std::string(trimmed_comment);
   }
 
   NewResourceBuilder res_builder(res->name);
@@ -362,7 +362,7 @@
       // Trim leading whitespace.
       StringPiece trimmed = util::TrimLeadingWhitespace(first_segment->data);
       if (trimmed.size() != first_segment->data.size()) {
-        first_segment->data = trimmed.to_string();
+        first_segment->data = std::string(trimmed);
       }
     }
 
@@ -370,7 +370,7 @@
       // Trim trailing whitespace.
       StringPiece trimmed = util::TrimTrailingWhitespace(last_segment->data);
       if (trimmed.size() != last_segment->data.size()) {
-        last_segment->data = trimmed.to_string();
+        last_segment->data = std::string(trimmed);
       }
     }
   }
@@ -466,7 +466,7 @@
 
     // Extract the product name if it exists.
     if (std::optional<StringPiece> maybe_product = xml::FindNonEmptyAttribute(parser, "product")) {
-      parsed_resource.product = maybe_product.value().to_string();
+      parsed_resource.product = std::string(maybe_product.value());
     }
 
     // Parse the resource regardless of product.
@@ -559,7 +559,7 @@
 
     // Items have their type encoded in the type attribute.
     if (std::optional<StringPiece> maybe_type = xml::FindNonEmptyAttribute(parser, "type")) {
-      resource_type = maybe_type.value().to_string();
+      resource_type = std::string(maybe_type.value());
     } else {
       diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number()))
                    << "<item> must have a 'type' attribute");
@@ -582,7 +582,7 @@
 
     // Bags have their type encoded in the type attribute.
     if (std::optional<StringPiece> maybe_type = xml::FindNonEmptyAttribute(parser, "type")) {
-      resource_type = maybe_type.value().to_string();
+      resource_type = std::string(maybe_type.value());
     } else {
       diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number()))
                    << "<bag> must have a 'type' attribute");
@@ -603,7 +603,7 @@
 
     out_resource->name.type =
         ResourceNamedTypeWithDefaultName(ResourceType::kId).ToResourceNamedType();
-    out_resource->name.entry = maybe_name.value().to_string();
+    out_resource->name.entry = std::string(maybe_name.value());
 
     // Ids either represent a unique resource id or reference another resource id
     auto item = ParseItem(parser, out_resource, resource_format);
@@ -640,7 +640,7 @@
 
     out_resource->name.type =
         ResourceNamedTypeWithDefaultName(ResourceType::kMacro).ToResourceNamedType();
-    out_resource->name.entry = maybe_name.value().to_string();
+    out_resource->name.entry = std::string(maybe_name.value());
     return ParseMacro(parser, out_resource);
   }
 
@@ -657,7 +657,7 @@
 
       out_resource->name.type =
           ResourceNamedTypeWithDefaultName(item_iter->second.type).ToResourceNamedType();
-      out_resource->name.entry = maybe_name.value().to_string();
+      out_resource->name.entry = std::string(maybe_name.value());
 
       // Only use the implied format of the type when there is no explicit format.
       if (resource_format == 0u) {
@@ -684,7 +684,7 @@
           return false;
         }
 
-        out_resource->name.entry = maybe_name.value().to_string();
+        out_resource->name.entry = std::string(maybe_name.value());
       }
 
       // Call the associated parse method. The type will be filled in by the
@@ -708,7 +708,7 @@
       }
 
       out_resource->name.type = parsed_type->ToResourceNamedType();
-      out_resource->name.entry = maybe_name.value().to_string();
+      out_resource->name.entry = std::string(maybe_name.value());
       out_resource->value = ParseXml(parser, android::ResTable_map::TYPE_REFERENCE, kNoRawString);
       if (!out_resource->value) {
         diag_->Error(android::DiagMessage(out_resource->source)
@@ -1005,7 +1005,7 @@
   const size_t depth = parser->depth();
   while (xml::XmlPullParser::NextChildNode(parser, depth)) {
     if (parser->event() == xml::XmlPullParser::Event::kComment) {
-      comment = util::TrimWhitespace(parser->comment()).to_string();
+      comment = std::string(util::TrimWhitespace(parser->comment()));
       continue;
     } else if (parser->event() != xml::XmlPullParser::Event::kStartElement) {
       // Skip text.
@@ -1045,7 +1045,7 @@
       }
 
       ParsedResource& entry_res = out_resource->child_resources.emplace_back(ParsedResource{
-          .name = ResourceName{{}, parsed_type, maybe_name.value().to_string()},
+          .name = ResourceName{{}, parsed_type, std::string(maybe_name.value())},
           .source = item_source,
           .comment = std::move(comment),
       });
@@ -1231,7 +1231,7 @@
 
       ParsedResource child_resource{};
       child_resource.name.type = type->ToResourceNamedType();
-      child_resource.name.entry = item_name.value().to_string();
+      child_resource.name.entry = std::string(item_name.value());
       child_resource.overlayable_item = overlayable_item;
       out_resource->child_resources.push_back(std::move(child_resource));
 
@@ -1246,7 +1246,7 @@
                      xml::FindNonEmptyAttribute(parser, "type")) {
         // Parse the polices separated by vertical bar characters to allow for specifying multiple
         // policies. Items within the policy tag will have the specified policy.
-        for (const StringPiece& part : util::Tokenize(maybe_type.value(), '|')) {
+        for (StringPiece part : util::Tokenize(maybe_type.value(), '|')) {
           StringPiece trimmed_part = util::TrimWhitespace(part);
           const auto policy = std::find_if(kPolicyStringToFlag.begin(),
                                            kPolicyStringToFlag.end(),
@@ -1377,7 +1377,7 @@
   const size_t depth = parser->depth();
   while (xml::XmlPullParser::NextChildNode(parser, depth)) {
     if (parser->event() == xml::XmlPullParser::Event::kComment) {
-      comment = util::TrimWhitespace(parser->comment()).to_string();
+      comment = std::string(util::TrimWhitespace(parser->comment()));
       continue;
     } else if (parser->event() != xml::XmlPullParser::Event::kStartElement) {
       // Skip text.
@@ -1457,7 +1457,7 @@
 }
 
 std::optional<Attribute::Symbol> ResourceParser::ParseEnumOrFlagItem(xml::XmlPullParser* parser,
-                                                                     const StringPiece& tag) {
+                                                                     StringPiece tag) {
   const android::Source source = source_.WithLine(parser->line_number());
 
   std::optional<StringPiece> maybe_name = xml::FindNonEmptyAttribute(parser, "name");
@@ -1764,7 +1764,7 @@
   const size_t depth = parser->depth();
   while (xml::XmlPullParser::NextChildNode(parser, depth)) {
     if (parser->event() == xml::XmlPullParser::Event::kComment) {
-      comment = util::TrimWhitespace(parser->comment()).to_string();
+      comment = std::string(util::TrimWhitespace(parser->comment()));
       continue;
     } else if (parser->event() != xml::XmlPullParser::Event::kStartElement) {
       // Ignore text.
diff --git a/tools/aapt2/ResourceParser.h b/tools/aapt2/ResourceParser.h
index 396ce97..012a056 100644
--- a/tools/aapt2/ResourceParser.h
+++ b/tools/aapt2/ResourceParser.h
@@ -122,7 +122,7 @@
   bool ParseAttr(xml::XmlPullParser* parser, ParsedResource* out_resource);
   bool ParseAttrImpl(xml::XmlPullParser* parser, ParsedResource* out_resource, bool weak);
   std::optional<Attribute::Symbol> ParseEnumOrFlagItem(xml::XmlPullParser* parser,
-                                                       const android::StringPiece& tag);
+                                                       android::StringPiece tag);
   bool ParseStyle(ResourceType type, xml::XmlPullParser* parser, ParsedResource* out_resource);
   bool ParseStyleItem(xml::XmlPullParser* parser, Style* style);
   bool ParseDeclareStyleable(xml::XmlPullParser* parser, ParsedResource* out_resource);
diff --git a/tools/aapt2/ResourceParser_test.cpp b/tools/aapt2/ResourceParser_test.cpp
index fe7eb96..b59b165 100644
--- a/tools/aapt2/ResourceParser_test.cpp
+++ b/tools/aapt2/ResourceParser_test.cpp
@@ -65,11 +65,11 @@
     context_ = test::ContextBuilder().Build();
   }
 
-  ::testing::AssertionResult TestParse(const StringPiece& str) {
+  ::testing::AssertionResult TestParse(StringPiece str) {
     return TestParse(str, ConfigDescription{});
   }
 
-  ::testing::AssertionResult TestParse(const StringPiece& str, const ConfigDescription& config) {
+  ::testing::AssertionResult TestParse(StringPiece str, const ConfigDescription& config) {
     ResourceParserOptions parserOptions;
     ResourceParser parser(context_->GetDiagnostics(), &table_, android::Source{"test"}, config,
                           parserOptions);
diff --git a/tools/aapt2/ResourceTable.cpp b/tools/aapt2/ResourceTable.cpp
index cb48114..a3b0b45 100644
--- a/tools/aapt2/ResourceTable.cpp
+++ b/tools/aapt2/ResourceTable.cpp
@@ -49,21 +49,21 @@
 }
 
 template <typename T>
-bool less_than_struct_with_name(const std::unique_ptr<T>& lhs, const StringPiece& rhs) {
+bool less_than_struct_with_name(const std::unique_ptr<T>& lhs, StringPiece rhs) {
   return lhs->name.compare(0, lhs->name.size(), rhs.data(), rhs.size()) < 0;
 }
 
 template <typename T>
-bool greater_than_struct_with_name(const StringPiece& lhs, const std::unique_ptr<T>& rhs) {
+bool greater_than_struct_with_name(StringPiece lhs, const std::unique_ptr<T>& rhs) {
   return rhs->name.compare(0, rhs->name.size(), lhs.data(), lhs.size()) > 0;
 }
 
 template <typename T>
 struct NameEqualRange {
-  bool operator()(const std::unique_ptr<T>& lhs, const StringPiece& rhs) const {
+  bool operator()(const std::unique_ptr<T>& lhs, StringPiece rhs) const {
     return less_than_struct_with_name<T>(lhs, rhs);
   }
-  bool operator()(const StringPiece& lhs, const std::unique_ptr<T>& rhs) const {
+  bool operator()(StringPiece lhs, const std::unique_ptr<T>& rhs) const {
     return greater_than_struct_with_name<T>(lhs, rhs);
   }
 };
@@ -78,7 +78,7 @@
 }
 
 template <typename T, typename Func, typename Elements>
-T* FindElementsRunAction(const android::StringPiece& name, Elements& entries, Func action) {
+T* FindElementsRunAction(android::StringPiece name, Elements& entries, Func action) {
   const auto iter =
       std::lower_bound(entries.begin(), entries.end(), name, less_than_struct_with_name<T>);
   const bool found = iter != entries.end() && name == (*iter)->name;
@@ -87,7 +87,7 @@
 
 struct ConfigKey {
   const ConfigDescription* config;
-  const StringPiece& product;
+  StringPiece product;
 };
 
 template <typename T>
@@ -104,12 +104,12 @@
 ResourceTable::ResourceTable(ResourceTable::Validation validation) : validation_(validation) {
 }
 
-ResourceTablePackage* ResourceTable::FindPackage(const android::StringPiece& name) const {
+ResourceTablePackage* ResourceTable::FindPackage(android::StringPiece name) const {
   return FindElementsRunAction<ResourceTablePackage>(
       name, packages, [&](bool found, auto& iter) { return found ? iter->get() : nullptr; });
 }
 
-ResourceTablePackage* ResourceTable::FindOrCreatePackage(const android::StringPiece& name) {
+ResourceTablePackage* ResourceTable::FindOrCreatePackage(android::StringPiece name) {
   return FindElementsRunAction<ResourceTablePackage>(name, packages, [&](bool found, auto& iter) {
     return found ? iter->get() : packages.emplace(iter, new ResourceTablePackage(name))->get();
   });
@@ -139,18 +139,18 @@
   });
 }
 
-ResourceEntry* ResourceTableType::CreateEntry(const android::StringPiece& name) {
+ResourceEntry* ResourceTableType::CreateEntry(android::StringPiece name) {
   return FindElementsRunAction<ResourceEntry>(name, entries, [&](bool found, auto& iter) {
     return entries.emplace(iter, new ResourceEntry(name))->get();
   });
 }
 
-ResourceEntry* ResourceTableType::FindEntry(const android::StringPiece& name) const {
+ResourceEntry* ResourceTableType::FindEntry(android::StringPiece name) const {
   return FindElementsRunAction<ResourceEntry>(
       name, entries, [&](bool found, auto& iter) { return found ? iter->get() : nullptr; });
 }
 
-ResourceEntry* ResourceTableType::FindOrCreateEntry(const android::StringPiece& name) {
+ResourceEntry* ResourceTableType::FindOrCreateEntry(android::StringPiece name) {
   return FindElementsRunAction<ResourceEntry>(name, entries, [&](bool found, auto& iter) {
     return found ? iter->get() : entries.emplace(iter, new ResourceEntry(name))->get();
   });
@@ -183,7 +183,7 @@
 }
 
 ResourceConfigValue* ResourceEntry::FindOrCreateValue(const ConfigDescription& config,
-                                                      const StringPiece& product) {
+                                                      StringPiece product) {
   auto iter = std::lower_bound(values.begin(), values.end(), ConfigKey{&config, product},
                                lt_config_key_ref<std::unique_ptr<ResourceConfigValue>>);
   if (iter != values.end()) {
diff --git a/tools/aapt2/ResourceTable.h b/tools/aapt2/ResourceTable.h
index f49ce81..bb286a8 100644
--- a/tools/aapt2/ResourceTable.h
+++ b/tools/aapt2/ResourceTable.h
@@ -71,12 +71,11 @@
 
 struct Overlayable {
   Overlayable() = default;
-   Overlayable(const android::StringPiece& name, const android::StringPiece& actor)
-       : name(name.to_string()), actor(actor.to_string()) {}
-   Overlayable(const android::StringPiece& name, const android::StringPiece& actor,
-               const android::Source& source)
-       : name(name.to_string()), actor(actor.to_string()), source(source) {
-   }
+  Overlayable(android::StringPiece name, android::StringPiece actor) : name(name), actor(actor) {
+  }
+  Overlayable(android::StringPiece name, android::StringPiece actor, const android::Source& source)
+      : name(name), actor(actor), source(source) {
+  }
 
   static const char* kActorScheme;
   std::string name;
@@ -105,8 +104,9 @@
   // The actual Value.
   std::unique_ptr<Value> value;
 
-  ResourceConfigValue(const android::ConfigDescription& config, const android::StringPiece& product)
-      : config(config), product(product.to_string()) {}
+  ResourceConfigValue(const android::ConfigDescription& config, android::StringPiece product)
+      : config(config), product(product) {
+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ResourceConfigValue);
@@ -136,7 +136,8 @@
   // The resource's values for each configuration.
   std::vector<std::unique_ptr<ResourceConfigValue>> values;
 
-  explicit ResourceEntry(const android::StringPiece& name) : name(name.to_string()) {}
+  explicit ResourceEntry(android::StringPiece name) : name(name) {
+  }
 
   ResourceConfigValue* FindValue(const android::ConfigDescription& config,
                                  android::StringPiece product = {});
@@ -144,7 +145,7 @@
                                        android::StringPiece product = {}) const;
 
   ResourceConfigValue* FindOrCreateValue(const android::ConfigDescription& config,
-                                         const android::StringPiece& product);
+                                         android::StringPiece product);
   std::vector<ResourceConfigValue*> FindAllValues(const android::ConfigDescription& config);
 
   template <typename Func>
@@ -180,9 +181,9 @@
       : named_type(type.ToResourceNamedType()) {
   }
 
-  ResourceEntry* CreateEntry(const android::StringPiece& name);
-  ResourceEntry* FindEntry(const android::StringPiece& name) const;
-  ResourceEntry* FindOrCreateEntry(const android::StringPiece& name);
+  ResourceEntry* CreateEntry(android::StringPiece name);
+  ResourceEntry* FindEntry(android::StringPiece name) const;
+  ResourceEntry* FindOrCreateEntry(android::StringPiece name);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ResourceTableType);
@@ -194,7 +195,7 @@
 
   std::vector<std::unique_ptr<ResourceTableType>> types;
 
-  explicit ResourceTablePackage(const android::StringPiece& name) : name(name.to_string()) {
+  explicit ResourceTablePackage(android::StringPiece name) : name(name) {
   }
 
   ResourceTablePackage() = default;
@@ -319,8 +320,8 @@
   // Returns the package struct with the given name, or nullptr if such a package does not
   // exist. The empty string is a valid package and typically is used to represent the
   // 'current' package before it is known to the ResourceTable.
-  ResourceTablePackage* FindPackage(const android::StringPiece& name) const;
-  ResourceTablePackage* FindOrCreatePackage(const android::StringPiece& name);
+  ResourceTablePackage* FindPackage(android::StringPiece name) const;
+  ResourceTablePackage* FindOrCreatePackage(android::StringPiece name);
 
   std::unique_ptr<ResourceTable> Clone() const;
 
diff --git a/tools/aapt2/ResourceTable_test.cpp b/tools/aapt2/ResourceTable_test.cpp
index 0cf8473..54b98d1 100644
--- a/tools/aapt2/ResourceTable_test.cpp
+++ b/tools/aapt2/ResourceTable_test.cpp
@@ -187,7 +187,7 @@
 static ::testing::AssertionResult VisibilityOfResource(const ResourceTable& table,
                                                        const ResourceNameRef& name,
                                                        Visibility::Level level,
-                                                       const StringPiece& comment) {
+                                                       StringPiece comment) {
   std::optional<ResourceTable::SearchResult> result = table.FindResource(name);
   if (!result) {
     return ::testing::AssertionFailure() << "no resource '" << name << "' found in table";
diff --git a/tools/aapt2/ResourceUtils.cpp b/tools/aapt2/ResourceUtils.cpp
index 41c7435..5a118a9 100644
--- a/tools/aapt2/ResourceUtils.cpp
+++ b/tools/aapt2/ResourceUtils.cpp
@@ -109,8 +109,7 @@
   return name_out;
 }
 
-bool ParseResourceName(const StringPiece& str, ResourceNameRef* out_ref,
-                       bool* out_private) {
+bool ParseResourceName(StringPiece str, ResourceNameRef* out_ref, bool* out_private) {
   if (str.empty()) {
     return false;
   }
@@ -151,8 +150,8 @@
   return true;
 }
 
-bool ParseReference(const StringPiece& str, ResourceNameRef* out_ref,
-                    bool* out_create, bool* out_private) {
+bool ParseReference(StringPiece str, ResourceNameRef* out_ref, bool* out_create,
+                    bool* out_private) {
   StringPiece trimmed_str(util::TrimWhitespace(str));
   if (trimmed_str.empty()) {
     return false;
@@ -198,11 +197,11 @@
   return false;
 }
 
-bool IsReference(const StringPiece& str) {
+bool IsReference(StringPiece str) {
   return ParseReference(str, nullptr, nullptr, nullptr);
 }
 
-bool ParseAttributeReference(const StringPiece& str, ResourceNameRef* out_ref) {
+bool ParseAttributeReference(StringPiece str, ResourceNameRef* out_ref) {
   StringPiece trimmed_str(util::TrimWhitespace(str));
   if (trimmed_str.empty()) {
     return false;
@@ -235,7 +234,7 @@
   return false;
 }
 
-bool IsAttributeReference(const StringPiece& str) {
+bool IsAttributeReference(StringPiece str) {
   return ParseAttributeReference(str, nullptr);
 }
 
@@ -247,7 +246,7 @@
  * <[*]package>:[style/]<entry>
  * [[*]package:style/]<entry>
  */
-std::optional<Reference> ParseStyleParentReference(const StringPiece& str, std::string* out_error) {
+std::optional<Reference> ParseStyleParentReference(StringPiece str, std::string* out_error) {
   if (str.empty()) {
     return {};
   }
@@ -296,7 +295,7 @@
   return result;
 }
 
-std::optional<Reference> ParseXmlAttributeName(const StringPiece& str) {
+std::optional<Reference> ParseXmlAttributeName(StringPiece str) {
   StringPiece trimmed_str = util::TrimWhitespace(str);
   const char* start = trimmed_str.data();
   const char* const end = start + trimmed_str.size();
@@ -325,8 +324,7 @@
   return std::optional<Reference>(std::move(ref));
 }
 
-std::unique_ptr<Reference> TryParseReference(const StringPiece& str,
-                                             bool* out_create) {
+std::unique_ptr<Reference> TryParseReference(StringPiece str, bool* out_create) {
   ResourceNameRef ref;
   bool private_ref = false;
   if (ParseReference(str, &ref, out_create, &private_ref)) {
@@ -344,7 +342,7 @@
   return {};
 }
 
-std::unique_ptr<Item> TryParseNullOrEmpty(const StringPiece& str) {
+std::unique_ptr<Item> TryParseNullOrEmpty(StringPiece str) {
   const StringPiece trimmed_str(util::TrimWhitespace(str));
   if (trimmed_str == "@null") {
     return MakeNull();
@@ -365,8 +363,7 @@
                                             android::Res_value::DATA_NULL_EMPTY);
 }
 
-std::unique_ptr<BinaryPrimitive> TryParseEnumSymbol(const Attribute* enum_attr,
-                                                    const StringPiece& str) {
+std::unique_ptr<BinaryPrimitive> TryParseEnumSymbol(const Attribute* enum_attr, StringPiece str) {
   StringPiece trimmed_str(util::TrimWhitespace(str));
   for (const Attribute::Symbol& symbol : enum_attr->symbols) {
     // Enum symbols are stored as @package:id/symbol resources,
@@ -382,8 +379,7 @@
   return {};
 }
 
-std::unique_ptr<BinaryPrimitive> TryParseFlagSymbol(const Attribute* flag_attr,
-                                                    const StringPiece& str) {
+std::unique_ptr<BinaryPrimitive> TryParseFlagSymbol(const Attribute* flag_attr, StringPiece str) {
   android::Res_value flags = {};
   flags.dataType = android::Res_value::TYPE_INT_HEX;
   flags.data = 0u;
@@ -393,7 +389,7 @@
     return util::make_unique<BinaryPrimitive>(flags);
   }
 
-  for (const StringPiece& part : util::Tokenize(str, '|')) {
+  for (StringPiece part : util::Tokenize(str, '|')) {
     StringPiece trimmed_part = util::TrimWhitespace(part);
 
     bool flag_set = false;
@@ -429,7 +425,7 @@
   }
 }
 
-std::unique_ptr<BinaryPrimitive> TryParseColor(const StringPiece& str) {
+std::unique_ptr<BinaryPrimitive> TryParseColor(StringPiece str) {
   StringPiece color_str(util::TrimWhitespace(str));
   const char* start = color_str.data();
   const size_t len = color_str.size();
@@ -484,7 +480,7 @@
                : util::make_unique<BinaryPrimitive>(value);
 }
 
-std::optional<bool> ParseBool(const StringPiece& str) {
+std::optional<bool> ParseBool(StringPiece str) {
   StringPiece trimmed_str(util::TrimWhitespace(str));
   if (trimmed_str == "true" || trimmed_str == "TRUE" || trimmed_str == "True") {
     return std::optional<bool>(true);
@@ -495,7 +491,7 @@
   return {};
 }
 
-std::optional<uint32_t> ParseInt(const StringPiece& str) {
+std::optional<uint32_t> ParseInt(StringPiece str) {
   std::u16string str16 = android::util::Utf8ToUtf16(str);
   android::Res_value value;
   if (android::ResTable::stringToInt(str16.data(), str16.size(), &value)) {
@@ -504,7 +500,7 @@
   return {};
 }
 
-std::optional<ResourceId> ParseResourceId(const StringPiece& str) {
+std::optional<ResourceId> ParseResourceId(StringPiece str) {
   StringPiece trimmed_str(util::TrimWhitespace(str));
 
   std::u16string str16 = android::util::Utf8ToUtf16(trimmed_str);
@@ -520,7 +516,7 @@
   return {};
 }
 
-std::optional<int> ParseSdkVersion(const StringPiece& str) {
+std::optional<int> ParseSdkVersion(StringPiece str) {
   StringPiece trimmed_str(util::TrimWhitespace(str));
 
   std::u16string str16 = android::util::Utf8ToUtf16(trimmed_str);
@@ -539,14 +535,14 @@
   const StringPiece::const_iterator begin = std::begin(trimmed_str);
   const StringPiece::const_iterator end = std::end(trimmed_str);
   const StringPiece::const_iterator codename_end = std::find(begin, end, '.');
-  entry = GetDevelopmentSdkCodeNameVersion(trimmed_str.substr(begin, codename_end));
+  entry = GetDevelopmentSdkCodeNameVersion(StringPiece(begin, codename_end - begin));
   if (entry) {
     return entry.value();
   }
   return {};
 }
 
-std::unique_ptr<BinaryPrimitive> TryParseBool(const StringPiece& str) {
+std::unique_ptr<BinaryPrimitive> TryParseBool(StringPiece str) {
   if (std::optional<bool> maybe_result = ParseBool(str)) {
     const uint32_t data = maybe_result.value() ? 0xffffffffu : 0u;
     return util::make_unique<BinaryPrimitive>(android::Res_value::TYPE_INT_BOOLEAN, data);
@@ -559,7 +555,7 @@
                                             val ? 0xffffffffu : 0u);
 }
 
-std::unique_ptr<BinaryPrimitive> TryParseInt(const StringPiece& str) {
+std::unique_ptr<BinaryPrimitive> TryParseInt(StringPiece str) {
   std::u16string str16 = android::util::Utf8ToUtf16(util::TrimWhitespace(str));
   android::Res_value value;
   if (!android::ResTable::stringToInt(str16.data(), str16.size(), &value)) {
@@ -572,7 +568,7 @@
   return util::make_unique<BinaryPrimitive>(android::Res_value::TYPE_INT_DEC, val);
 }
 
-std::unique_ptr<BinaryPrimitive> TryParseFloat(const StringPiece& str) {
+std::unique_ptr<BinaryPrimitive> TryParseFloat(StringPiece str) {
   std::u16string str16 = android::util::Utf8ToUtf16(util::TrimWhitespace(str));
   android::Res_value value;
   if (!android::ResTable::stringToFloat(str16.data(), str16.size(), &value)) {
@@ -623,7 +619,7 @@
 }
 
 std::unique_ptr<Item> TryParseItemForAttribute(
-    const StringPiece& value, uint32_t type_mask,
+    StringPiece value, uint32_t type_mask,
     const std::function<bool(const ResourceName&)>& on_create_reference) {
   using android::ResTable_map;
 
@@ -687,7 +683,7 @@
  * allows.
  */
 std::unique_ptr<Item> TryParseItemForAttribute(
-    const StringPiece& str, const Attribute* attr,
+    StringPiece str, const Attribute* attr,
     const std::function<bool(const ResourceName&)>& on_create_reference) {
   using android::ResTable_map;
 
diff --git a/tools/aapt2/ResourceUtils.h b/tools/aapt2/ResourceUtils.h
index 22cf345..f30f4ac 100644
--- a/tools/aapt2/ResourceUtils.h
+++ b/tools/aapt2/ResourceUtils.h
@@ -38,7 +38,7 @@
  * `out_resource` set to the parsed resource name and `out_private` set to true
  * if a '*' prefix was present.
  */
-bool ParseResourceName(const android::StringPiece& str, ResourceNameRef* out_resource,
+bool ParseResourceName(android::StringPiece str, ResourceNameRef* out_resource,
                        bool* out_private = nullptr);
 
 /*
@@ -49,27 +49,27 @@
  * If '+' was present in the reference, `out_create` is set to true.
  * If '*' was present in the reference, `out_private` is set to true.
  */
-bool ParseReference(const android::StringPiece& str, ResourceNameRef* out_reference,
+bool ParseReference(android::StringPiece str, ResourceNameRef* out_reference,
                     bool* out_create = nullptr, bool* out_private = nullptr);
 
 /*
  * Returns true if the string is in the form of a resource reference
  * (@[+][package:]type/name).
  */
-bool IsReference(const android::StringPiece& str);
+bool IsReference(android::StringPiece str);
 
 /*
  * Returns true if the string was parsed as an attribute reference
  * (?[package:][type/]name),
  * with `out_reference` set to the parsed reference.
  */
-bool ParseAttributeReference(const android::StringPiece& str, ResourceNameRef* out_reference);
+bool ParseAttributeReference(android::StringPiece str, ResourceNameRef* out_reference);
 
 /**
  * Returns true if the string is in the form of an attribute
  * reference(?[package:][type/]name).
  */
-bool IsAttributeReference(const android::StringPiece& str);
+bool IsAttributeReference(android::StringPiece str);
 
 /**
  * Convert an android::ResTable::resource_name to an aapt::ResourceName struct.
@@ -85,22 +85,22 @@
  * Returns a boolean value if the string is equal to TRUE, true, True, FALSE,
  * false, or False.
  */
-std::optional<bool> ParseBool(const android::StringPiece& str);
+std::optional<bool> ParseBool(android::StringPiece str);
 
 /**
  * Returns a uint32_t if the string is an integer.
  */
-std::optional<uint32_t> ParseInt(const android::StringPiece& str);
+std::optional<uint32_t> ParseInt(android::StringPiece str);
 
 /**
  * Returns an ID if it the string represented a valid ID.
  */
-std::optional<ResourceId> ParseResourceId(const android::StringPiece& str);
+std::optional<ResourceId> ParseResourceId(android::StringPiece str);
 
 /**
  * Parses an SDK version, which can be an integer, or a letter from A-Z.
  */
-std::optional<int> ParseSdkVersion(const android::StringPiece& str);
+std::optional<int> ParseSdkVersion(android::StringPiece str);
 
 /*
  * Returns a Reference, or None Maybe instance if the string `str` was parsed as
@@ -113,7 +113,7 @@
  * ?[package:]style/<entry> or
  * <package>:[style/]<entry>
  */
-std::optional<Reference> ParseStyleParentReference(const android::StringPiece& str,
+std::optional<Reference> ParseStyleParentReference(android::StringPiece str,
                                                    std::string* out_error);
 
 /*
@@ -123,7 +123,7 @@
  *
  * package:entry
  */
-std::optional<Reference> ParseXmlAttributeName(const android::StringPiece& str);
+std::optional<Reference> ParseXmlAttributeName(android::StringPiece str);
 
 /*
  * Returns a Reference object if the string was parsed as a resource or
@@ -132,14 +132,13 @@
  * if
  * the '+' was present in the string.
  */
-std::unique_ptr<Reference> TryParseReference(const android::StringPiece& str,
-                                             bool* out_create = nullptr);
+std::unique_ptr<Reference> TryParseReference(android::StringPiece str, bool* out_create = nullptr);
 
 /*
  * Returns a BinaryPrimitve object representing @null or @empty if the string
  * was parsed as one.
  */
-std::unique_ptr<Item> TryParseNullOrEmpty(const android::StringPiece& str);
+std::unique_ptr<Item> TryParseNullOrEmpty(android::StringPiece str);
 
 // Returns a Reference representing @null.
 // Due to runtime compatibility issues, this is encoded as a reference with ID 0.
@@ -154,13 +153,13 @@
  * Returns a BinaryPrimitve object representing a color if the string was parsed
  * as one.
  */
-std::unique_ptr<BinaryPrimitive> TryParseColor(const android::StringPiece& str);
+std::unique_ptr<BinaryPrimitive> TryParseColor(android::StringPiece str);
 
 /*
  * Returns a BinaryPrimitve object representing a boolean if the string was
  * parsed as one.
  */
-std::unique_ptr<BinaryPrimitive> TryParseBool(const android::StringPiece& str);
+std::unique_ptr<BinaryPrimitive> TryParseBool(android::StringPiece str);
 
 // Returns a boolean BinaryPrimitive.
 std::unique_ptr<BinaryPrimitive> MakeBool(bool val);
@@ -169,7 +168,7 @@
  * Returns a BinaryPrimitve object representing an integer if the string was
  * parsed as one.
  */
-std::unique_ptr<BinaryPrimitive> TryParseInt(const android::StringPiece& str);
+std::unique_ptr<BinaryPrimitive> TryParseInt(android::StringPiece str);
 
 // Returns an integer BinaryPrimitive.
 std::unique_ptr<BinaryPrimitive> MakeInt(uint32_t value);
@@ -178,21 +177,21 @@
  * Returns a BinaryPrimitve object representing a floating point number
  * (float, dimension, etc) if the string was parsed as one.
  */
-std::unique_ptr<BinaryPrimitive> TryParseFloat(const android::StringPiece& str);
+std::unique_ptr<BinaryPrimitive> TryParseFloat(android::StringPiece str);
 
 /*
  * Returns a BinaryPrimitve object representing an enum symbol if the string was
  * parsed as one.
  */
 std::unique_ptr<BinaryPrimitive> TryParseEnumSymbol(const Attribute* enum_attr,
-                                                    const android::StringPiece& str);
+                                                    android::StringPiece str);
 
 /*
  * Returns a BinaryPrimitve object representing a flag symbol if the string was
  * parsed as one.
  */
 std::unique_ptr<BinaryPrimitive> TryParseFlagSymbol(const Attribute* enum_attr,
-                                                    const android::StringPiece& str);
+                                                    android::StringPiece str);
 /*
  * Try to convert a string to an Item for the given attribute. The attribute
  * will
@@ -201,11 +200,11 @@
  * reference to an ID that must be created (@+id/foo).
  */
 std::unique_ptr<Item> TryParseItemForAttribute(
-    const android::StringPiece& value, const Attribute* attr,
+    android::StringPiece value, const Attribute* attr,
     const std::function<bool(const ResourceName&)>& on_create_reference = {});
 
 std::unique_ptr<Item> TryParseItemForAttribute(
-    const android::StringPiece& value, uint32_t type_mask,
+    android::StringPiece value, uint32_t type_mask,
     const std::function<bool(const ResourceName&)>& on_create_reference = {});
 
 uint32_t AndroidTypeToAttributeTypeMask(uint16_t type);
diff --git a/tools/aapt2/ResourceValues.cpp b/tools/aapt2/ResourceValues.cpp
index c4d54be..a5754e0 100644
--- a/tools/aapt2/ResourceValues.cpp
+++ b/tools/aapt2/ResourceValues.cpp
@@ -206,7 +206,7 @@
   PrettyPrintReferenceImpl(*this, true /*print_package*/, printer);
 }
 
-void Reference::PrettyPrint(const StringPiece& package, Printer* printer) const {
+void Reference::PrettyPrint(StringPiece package, Printer* printer) const {
   const bool print_package = name ? package != name.value().package : true;
   PrettyPrintReferenceImpl(*this, print_package, printer);
 }
diff --git a/tools/aapt2/ResourceValues.h b/tools/aapt2/ResourceValues.h
index f5167a1..6f9dccb 100644
--- a/tools/aapt2/ResourceValues.h
+++ b/tools/aapt2/ResourceValues.h
@@ -83,8 +83,8 @@
     return comment_;
   }
 
-  void SetComment(const android::StringPiece& str) {
-    comment_ = str.to_string();
+  void SetComment(android::StringPiece str) {
+    comment_.assign(str);
   }
 
   void SetComment(std::string&& str) {
@@ -176,7 +176,7 @@
   void PrettyPrint(text::Printer* printer) const override;
 
   // Prints the reference without a package name if the package name matches the one given.
-  void PrettyPrint(const android::StringPiece& package, text::Printer* printer) const;
+  void PrettyPrint(android::StringPiece package, text::Printer* printer) const;
 };
 
 bool operator<(const Reference&, const Reference&);
diff --git a/tools/aapt2/SdkConstants.cpp b/tools/aapt2/SdkConstants.cpp
index 34e8edb..a7c5479 100644
--- a/tools/aapt2/SdkConstants.cpp
+++ b/tools/aapt2/SdkConstants.cpp
@@ -77,7 +77,7 @@
   return iter->second;
 }
 
-std::optional<ApiVersion> GetDevelopmentSdkCodeNameVersion(const StringPiece& code_name) {
+std::optional<ApiVersion> GetDevelopmentSdkCodeNameVersion(StringPiece code_name) {
   return (sDevelopmentSdkCodeNames.find(code_name) == sDevelopmentSdkCodeNames.end())
              ? std::optional<ApiVersion>()
              : sDevelopmentSdkLevel;
diff --git a/tools/aapt2/SdkConstants.h b/tools/aapt2/SdkConstants.h
index 0bd61c0..40bcef7 100644
--- a/tools/aapt2/SdkConstants.h
+++ b/tools/aapt2/SdkConstants.h
@@ -63,7 +63,7 @@
 };
 
 ApiVersion FindAttributeSdkLevel(const ResourceId& id);
-std::optional<ApiVersion> GetDevelopmentSdkCodeNameVersion(const android::StringPiece& code_name);
+std::optional<ApiVersion> GetDevelopmentSdkCodeNameVersion(android::StringPiece code_name);
 
 }  // namespace aapt
 
diff --git a/tools/aapt2/cmd/ApkInfo.cpp b/tools/aapt2/cmd/ApkInfo.cpp
index 697b110..3c0831c 100644
--- a/tools/aapt2/cmd/ApkInfo.cpp
+++ b/tools/aapt2/cmd/ApkInfo.cpp
@@ -64,7 +64,7 @@
     Usage(&std::cerr);
     return 1;
   }
-  const StringPiece& path = args[0];
+  StringPiece path = args[0];
   std::unique_ptr<LoadedApk> apk = LoadedApk::LoadApkFromPath(path, diag_);
   if (!apk) {
     return 1;
diff --git a/tools/aapt2/cmd/Command.cpp b/tools/aapt2/cmd/Command.cpp
index b1452fa..514651e 100644
--- a/tools/aapt2/cmd/Command.cpp
+++ b/tools/aapt2/cmd/Command.cpp
@@ -33,7 +33,7 @@
 
 namespace aapt {
 
-std::string GetSafePath(const StringPiece& arg) {
+std::string GetSafePath(StringPiece arg) {
 #ifdef _WIN32
   // If the path exceeds the maximum path length for Windows, encode the path using the
   // extended-length prefix
@@ -47,63 +47,62 @@
 
   return path8;
 #else
-  return arg.to_string();
+  return std::string(arg);
 #endif
 }
 
-void Command::AddRequiredFlag(const StringPiece& name, const StringPiece& description,
-                              std::string* value, uint32_t flags) {
-  auto func = [value, flags](const StringPiece& arg) -> bool {
-    *value = (flags & Command::kPath) ? GetSafePath(arg) : arg.to_string();
+void Command::AddRequiredFlag(StringPiece name, StringPiece description, std::string* value,
+                              uint32_t flags) {
+  auto func = [value, flags](StringPiece arg) -> bool {
+    *value = (flags & Command::kPath) ? GetSafePath(arg) : std::string(arg);
     return true;
   };
 
   flags_.emplace_back(Flag(name, description, /* required */ true, /* num_args */ 1, func));
 }
 
-void Command::AddRequiredFlagList(const StringPiece& name, const StringPiece& description,
+void Command::AddRequiredFlagList(StringPiece name, StringPiece description,
                                   std::vector<std::string>* value, uint32_t flags) {
-  auto func = [value, flags](const StringPiece& arg) -> bool {
-    value->push_back((flags & Command::kPath) ? GetSafePath(arg) : arg.to_string());
+  auto func = [value, flags](StringPiece arg) -> bool {
+    value->push_back((flags & Command::kPath) ? GetSafePath(arg) : std::string(arg));
     return true;
   };
 
   flags_.emplace_back(Flag(name, description, /* required */ true, /* num_args */ 1, func));
 }
 
-void Command::AddOptionalFlag(const StringPiece& name, const StringPiece& description,
+void Command::AddOptionalFlag(StringPiece name, StringPiece description,
                               std::optional<std::string>* value, uint32_t flags) {
-  auto func = [value, flags](const StringPiece& arg) -> bool {
-    *value = (flags & Command::kPath) ? GetSafePath(arg) : arg.to_string();
+  auto func = [value, flags](StringPiece arg) -> bool {
+    *value = (flags & Command::kPath) ? GetSafePath(arg) : std::string(arg);
     return true;
   };
 
   flags_.emplace_back(Flag(name, description, /* required */ false, /* num_args */ 1, func));
 }
 
-void Command::AddOptionalFlagList(const StringPiece& name, const StringPiece& description,
+void Command::AddOptionalFlagList(StringPiece name, StringPiece description,
                                   std::vector<std::string>* value, uint32_t flags) {
-  auto func = [value, flags](const StringPiece& arg) -> bool {
-    value->push_back((flags & Command::kPath) ? GetSafePath(arg) : arg.to_string());
+  auto func = [value, flags](StringPiece arg) -> bool {
+    value->push_back((flags & Command::kPath) ? GetSafePath(arg) : std::string(arg));
     return true;
   };
 
   flags_.emplace_back(Flag(name, description, /* required */ false, /* num_args */ 1, func));
 }
 
-void Command::AddOptionalFlagList(const StringPiece& name, const StringPiece& description,
+void Command::AddOptionalFlagList(StringPiece name, StringPiece description,
                                   std::unordered_set<std::string>* value) {
-  auto func = [value](const StringPiece& arg) -> bool {
-    value->insert(arg.to_string());
+  auto func = [value](StringPiece arg) -> bool {
+    value->emplace(arg);
     return true;
   };
 
   flags_.emplace_back(Flag(name, description, /* required */ false, /* num_args */ 1, func));
 }
 
-void Command::AddOptionalSwitch(const StringPiece& name, const StringPiece& description,
-                                bool* value) {
-  auto func = [value](const StringPiece& arg) -> bool {
+void Command::AddOptionalSwitch(StringPiece name, StringPiece description, bool* value) {
+  auto func = [value](StringPiece arg) -> bool {
     *value = true;
     return true;
   };
@@ -120,8 +119,8 @@
   }
 }
 
-void Command::SetDescription(const StringPiece& description) {
-  description_ = description.to_string();
+void Command::SetDescription(StringPiece description) {
+  description_ = std::string(description);
 }
 
 void Command::Usage(std::ostream* out) {
@@ -183,7 +182,7 @@
   std::vector<std::string> file_args;
 
   for (size_t i = 0; i < args.size(); i++) {
-    const StringPiece& arg = args[i];
+    StringPiece arg = args[i];
     if (*(arg.data()) != '-') {
       // Continue parsing as the subcommand if the first argument matches one of the subcommands
       if (i == 0) {
diff --git a/tools/aapt2/cmd/Command.h b/tools/aapt2/cmd/Command.h
index 8678cda..1416e98 100644
--- a/tools/aapt2/cmd/Command.h
+++ b/tools/aapt2/cmd/Command.h
@@ -30,13 +30,10 @@
 
 class Command {
  public:
-  explicit Command(const android::StringPiece& name)
-      : name_(name.to_string()), full_subcommand_name_(name.to_string()){};
+  explicit Command(android::StringPiece name) : name_(name), full_subcommand_name_(name){};
 
-  explicit Command(const android::StringPiece& name, const android::StringPiece& short_name)
-      : name_(name.to_string()),
-        short_name_(short_name.to_string()),
-        full_subcommand_name_(name.to_string()){};
+  explicit Command(android::StringPiece name, android::StringPiece short_name)
+      : name_(name), short_name_(short_name), full_subcommand_name_(name){};
 
   Command(Command&&) = default;
   Command& operator=(Command&&) = default;
@@ -52,30 +49,26 @@
     kPath = 1 << 0,
   };
 
-  void AddRequiredFlag(const android::StringPiece& name, const android::StringPiece& description,
+  void AddRequiredFlag(android::StringPiece name, android::StringPiece description,
                        std::string* value, uint32_t flags = 0);
 
-  void AddRequiredFlagList(const android::StringPiece& name,
-                           const android::StringPiece& description, std::vector<std::string>* value,
-                           uint32_t flags = 0);
+  void AddRequiredFlagList(android::StringPiece name, android::StringPiece description,
+                           std::vector<std::string>* value, uint32_t flags = 0);
 
-  void AddOptionalFlag(const android::StringPiece& name, const android::StringPiece& description,
+  void AddOptionalFlag(android::StringPiece name, android::StringPiece description,
                        std::optional<std::string>* value, uint32_t flags = 0);
 
-  void AddOptionalFlagList(const android::StringPiece& name,
-                           const android::StringPiece& description, std::vector<std::string>* value,
-                           uint32_t flags = 0);
+  void AddOptionalFlagList(android::StringPiece name, android::StringPiece description,
+                           std::vector<std::string>* value, uint32_t flags = 0);
 
-  void AddOptionalFlagList(const android::StringPiece& name,
-                           const android::StringPiece& description,
+  void AddOptionalFlagList(android::StringPiece name, android::StringPiece description,
                            std::unordered_set<std::string>* value);
 
-  void AddOptionalSwitch(const android::StringPiece& name, const android::StringPiece& description,
-                         bool* value);
+  void AddOptionalSwitch(android::StringPiece name, android::StringPiece description, bool* value);
 
   void AddOptionalSubcommand(std::unique_ptr<Command>&& subcommand, bool experimental = false);
 
-  void SetDescription(const android::StringPiece& name);
+  void SetDescription(android::StringPiece name);
 
   // Prints the help menu of the command.
   void Usage(std::ostream* out);
@@ -90,17 +83,21 @@
 
  private:
   struct Flag {
-    explicit Flag(const android::StringPiece& name, const android::StringPiece& description,
+    explicit Flag(android::StringPiece name, android::StringPiece description,
                   const bool is_required, const size_t num_args,
-                  std::function<bool(const android::StringPiece& value)>&& action)
-        : name(name.to_string()), description(description.to_string()), is_required(is_required),
-          num_args(num_args), action(std::move(action)) {}
+                  std::function<bool(android::StringPiece value)>&& action)
+        : name(name),
+          description(description),
+          is_required(is_required),
+          num_args(num_args),
+          action(std::move(action)) {
+    }
 
     const std::string name;
     const std::string description;
     const bool is_required;
     const size_t num_args;
-    const std::function<bool(const android::StringPiece& value)> action;
+    const std::function<bool(android::StringPiece value)> action;
     bool found = false;
   };
 
diff --git a/tools/aapt2/cmd/Compile.cpp b/tools/aapt2/cmd/Compile.cpp
index 0409f73..03f9715 100644
--- a/tools/aapt2/cmd/Compile.cpp
+++ b/tools/aapt2/cmd/Compile.cpp
@@ -125,8 +125,12 @@
   const android::Source res_path =
       options.source_path ? StringPiece(options.source_path.value()) : StringPiece(path);
 
-  return ResourcePathData{res_path, dir_str.to_string(), name.to_string(),
-                          extension.to_string(), config_str.to_string(), config};
+  return ResourcePathData{res_path,
+                          std::string(dir_str),
+                          std::string(name),
+                          std::string(extension),
+                          std::string(config_str),
+                          config};
 }
 
 static std::string BuildIntermediateContainerFilename(const ResourcePathData& data) {
@@ -279,7 +283,7 @@
   return true;
 }
 
-static bool WriteHeaderAndDataToWriter(const StringPiece& output_path, const ResourceFile& file,
+static bool WriteHeaderAndDataToWriter(StringPiece output_path, const ResourceFile& file,
                                        io::KnownSizeInputStream* in, IArchiveWriter* writer,
                                        android::IDiagnostics* diag) {
   TRACE_CALL();
@@ -311,7 +315,7 @@
   return true;
 }
 
-static bool FlattenXmlToOutStream(const StringPiece& output_path, const xml::XmlResource& xmlres,
+static bool FlattenXmlToOutStream(StringPiece output_path, const xml::XmlResource& xmlres,
                                   ContainerWriter* container_writer, android::IDiagnostics* diag) {
   pb::internal::CompiledFile pb_compiled_file;
   SerializeCompiledFileToPb(xmlres.file, &pb_compiled_file);
@@ -538,7 +542,7 @@
     if (context->IsVerbose()) {
       // For debugging only, use the legacy PNG cruncher and compare the resulting file sizes.
       // This will help catch exotic cases where the new code may generate larger PNGs.
-      std::stringstream legacy_stream(content.to_string());
+      std::stringstream legacy_stream{std::string(content)};
       android::BigBuffer legacy_buffer(4096);
       Png png(context->GetDiagnostics());
       if (!png.process(path_data.source, &legacy_stream, &legacy_buffer, {})) {
diff --git a/tools/aapt2/cmd/Convert.cpp b/tools/aapt2/cmd/Convert.cpp
index 52e113e..612e3a6 100644
--- a/tools/aapt2/cmd/Convert.cpp
+++ b/tools/aapt2/cmd/Convert.cpp
@@ -387,7 +387,7 @@
   }
 
   Context context;
-  const StringPiece& path = args[0];
+  StringPiece path = args[0];
   unique_ptr<LoadedApk> apk = LoadedApk::LoadApkFromPath(path, context.GetDiagnostics());
   if (apk == nullptr) {
     context.GetDiagnostics()->Error(android::DiagMessage(path) << "failed to load APK");
diff --git a/tools/aapt2/cmd/Diff.cpp b/tools/aapt2/cmd/Diff.cpp
index 423e939..5bfc732 100644
--- a/tools/aapt2/cmd/Diff.cpp
+++ b/tools/aapt2/cmd/Diff.cpp
@@ -78,7 +78,7 @@
   SymbolTable symbol_table_;
 };
 
-static void EmitDiffLine(const android::Source& source, const StringPiece& message) {
+static void EmitDiffLine(const android::Source& source, StringPiece message) {
   std::cerr << source << ": " << message << "\n";
 }
 
diff --git a/tools/aapt2/cmd/Link.cpp b/tools/aapt2/cmd/Link.cpp
index a8d2299..97404fc 100644
--- a/tools/aapt2/cmd/Link.cpp
+++ b/tools/aapt2/cmd/Link.cpp
@@ -126,8 +126,8 @@
     return compilation_package_;
   }
 
-  void SetCompilationPackage(const StringPiece& package_name) {
-    compilation_package_ = package_name.to_string();
+  void SetCompilationPackage(StringPiece package_name) {
+    compilation_package_ = std::string(package_name);
   }
 
   uint8_t GetPackageId() override {
@@ -240,9 +240,9 @@
   IAaptContext* context_;
 };
 
-static bool FlattenXml(IAaptContext* context, const xml::XmlResource& xml_res,
-                       const StringPiece& path, bool keep_raw_values, bool utf16,
-                       OutputFormat format, IArchiveWriter* writer) {
+static bool FlattenXml(IAaptContext* context, const xml::XmlResource& xml_res, StringPiece path,
+                       bool keep_raw_values, bool utf16, OutputFormat format,
+                       IArchiveWriter* writer) {
   TRACE_CALL();
   if (context->IsVerbose()) {
     context->GetDiagnostics()->Note(android::DiagMessage(path)
@@ -262,8 +262,8 @@
       }
 
       io::BigBufferInputStream input_stream(&buffer);
-      return io::CopyInputStreamToArchive(context, &input_stream, path.to_string(),
-                                          ArchiveEntry::kCompress, writer);
+      return io::CopyInputStreamToArchive(context, &input_stream, path, ArchiveEntry::kCompress,
+                                          writer);
     } break;
 
     case OutputFormat::kProto: {
@@ -272,8 +272,7 @@
       SerializeXmlOptions options;
       options.remove_empty_text_nodes = (path == kAndroidManifestPath);
       SerializeXmlResourceToPb(xml_res, &pb_node);
-      return io::CopyProtoToArchive(context, &pb_node, path.to_string(), ArchiveEntry::kCompress,
-                                    writer);
+      return io::CopyProtoToArchive(context, &pb_node, path, ArchiveEntry::kCompress, writer);
     } break;
   }
   return false;
@@ -329,13 +328,13 @@
 };
 
 template <typename T>
-uint32_t GetCompressionFlags(const StringPiece& str, T options) {
+uint32_t GetCompressionFlags(StringPiece str, T options) {
   if (options.do_not_compress_anything) {
     return 0;
   }
 
-  if (options.regex_to_not_compress
-      && std::regex_search(str.to_string(), options.regex_to_not_compress.value())) {
+  if (options.regex_to_not_compress &&
+      std::regex_search(str.begin(), str.end(), options.regex_to_not_compress.value())) {
     return 0;
   }
 
@@ -1176,7 +1175,7 @@
     return bcp47tag;
   }
 
-  std::unique_ptr<IArchiveWriter> MakeArchiveWriter(const StringPiece& out) {
+  std::unique_ptr<IArchiveWriter> MakeArchiveWriter(StringPiece out) {
     if (options_.output_to_directory) {
       return CreateDirectoryArchiveWriter(context_->GetDiagnostics(), out);
     } else {
@@ -1212,8 +1211,8 @@
     return false;
   }
 
-  bool WriteJavaFile(ResourceTable* table, const StringPiece& package_name_to_generate,
-                     const StringPiece& out_package, const JavaClassGeneratorOptions& java_options,
+  bool WriteJavaFile(ResourceTable* table, StringPiece package_name_to_generate,
+                     StringPiece out_package, const JavaClassGeneratorOptions& java_options,
                      const std::optional<std::string>& out_text_symbols_path = {}) {
     if (!options_.generate_java_class_path && !out_text_symbols_path) {
       return true;
@@ -2473,14 +2472,14 @@
   for (std::string& extra_package : extra_java_packages_) {
     // A given package can actually be a colon separated list of packages.
     for (StringPiece package : util::Split(extra_package, ':')) {
-      options_.extra_java_packages.insert(package.to_string());
+      options_.extra_java_packages.emplace(package);
     }
   }
 
   if (product_list_) {
     for (StringPiece product : util::Tokenize(product_list_.value(), ',')) {
       if (product != "" && product != "default") {
-        options_.products.insert(product.to_string());
+        options_.products.emplace(product);
       }
     }
   }
diff --git a/tools/aapt2/cmd/Optimize.cpp b/tools/aapt2/cmd/Optimize.cpp
index 042926c..9c1a2f6 100644
--- a/tools/aapt2/cmd/Optimize.cpp
+++ b/tools/aapt2/cmd/Optimize.cpp
@@ -370,8 +370,8 @@
 
     if (!kept_artifacts_.empty()) {
       for (const std::string& artifact_str : kept_artifacts_) {
-        for (const StringPiece& artifact : util::Tokenize(artifact_str, ',')) {
-          options_.kept_artifacts.insert(artifact.to_string());
+        for (StringPiece artifact : util::Tokenize(artifact_str, ',')) {
+          options_.kept_artifacts.emplace(artifact);
         }
       }
     }
@@ -403,7 +403,7 @@
 
   if (target_densities_) {
     // Parse the target screen densities.
-    for (const StringPiece& config_str : util::Tokenize(target_densities_.value(), ',')) {
+    for (StringPiece config_str : util::Tokenize(target_densities_.value(), ',')) {
       std::optional<uint16_t> target_density = ParseTargetDensityParameter(config_str, diag);
       if (!target_density) {
         return 1;
diff --git a/tools/aapt2/cmd/Util.cpp b/tools/aapt2/cmd/Util.cpp
index 56e2f52..92849cf 100644
--- a/tools/aapt2/cmd/Util.cpp
+++ b/tools/aapt2/cmd/Util.cpp
@@ -34,8 +34,7 @@
 
 namespace aapt {
 
-std::optional<uint16_t> ParseTargetDensityParameter(const StringPiece& arg,
-                                                    android::IDiagnostics* diag) {
+std::optional<uint16_t> ParseTargetDensityParameter(StringPiece arg, android::IDiagnostics* diag) {
   ConfigDescription preferred_density_config;
   if (!ConfigDescription::Parse(arg, &preferred_density_config)) {
     diag->Error(android::DiagMessage()
@@ -55,7 +54,7 @@
   return preferred_density_config.density;
 }
 
-bool ParseSplitParameter(const StringPiece& arg, android::IDiagnostics* diag, std::string* out_path,
+bool ParseSplitParameter(StringPiece arg, android::IDiagnostics* diag, std::string* out_path,
                          SplitConstraints* out_split) {
   CHECK(diag != nullptr);
   CHECK(out_path != nullptr);
@@ -77,7 +76,7 @@
 
   *out_path = parts[0];
   out_split->name = parts[1];
-  for (const StringPiece& config_str : util::Tokenize(parts[1], ',')) {
+  for (StringPiece config_str : util::Tokenize(parts[1], ',')) {
     ConfigDescription config;
     if (!ConfigDescription::Parse(config_str, &config)) {
       diag->Error(android::DiagMessage()
@@ -93,7 +92,7 @@
                                                            android::IDiagnostics* diag) {
   std::unique_ptr<AxisConfigFilter> filter = util::make_unique<AxisConfigFilter>();
   for (const std::string& config_arg : args) {
-    for (const StringPiece& config_str : util::Tokenize(config_arg, ',')) {
+    for (StringPiece config_str : util::Tokenize(config_arg, ',')) {
       ConfigDescription config;
       LocaleValue lv;
       if (lv.InitFromFilterString(config_str)) {
diff --git a/tools/aapt2/cmd/Util.h b/tools/aapt2/cmd/Util.h
index 3d4ca24..169d5f9 100644
--- a/tools/aapt2/cmd/Util.h
+++ b/tools/aapt2/cmd/Util.h
@@ -34,13 +34,13 @@
 
 // Parses a configuration density (ex. hdpi, xxhdpi, 234dpi, anydpi, etc).
 // Returns Nothing and logs a human friendly error message if the string was not legal.
-std::optional<uint16_t> ParseTargetDensityParameter(const android::StringPiece& arg,
+std::optional<uint16_t> ParseTargetDensityParameter(android::StringPiece arg,
                                                     android::IDiagnostics* diag);
 
 // Parses a string of the form 'path/to/output.apk:<config>[,<config>...]' and fills in
 // `out_path` with the path and `out_split` with the set of ConfigDescriptions.
 // Returns false and logs a human friendly error message if the string was not legal.
-bool ParseSplitParameter(const android::StringPiece& arg, android::IDiagnostics* diag,
+bool ParseSplitParameter(android::StringPiece arg, android::IDiagnostics* diag,
                          std::string* out_path, SplitConstraints* out_split);
 
 // Parses a set of config filter strings of the form 'en,fr-rFR' and returns an IConfigFilter.
diff --git a/tools/aapt2/compile/NinePatch.cpp b/tools/aapt2/compile/NinePatch.cpp
index c931da4..4538ecc 100644
--- a/tools/aapt2/compile/NinePatch.cpp
+++ b/tools/aapt2/compile/NinePatch.cpp
@@ -218,11 +218,9 @@
 
 static bool PopulateBounds(const std::vector<Range>& padding,
                            const std::vector<Range>& layout_bounds,
-                           const std::vector<Range>& stretch_regions,
-                           const int32_t length, int32_t* padding_start,
-                           int32_t* padding_end, int32_t* layout_start,
-                           int32_t* layout_end, const StringPiece& edge_name,
-                           std::string* out_err) {
+                           const std::vector<Range>& stretch_regions, const int32_t length,
+                           int32_t* padding_start, int32_t* padding_end, int32_t* layout_start,
+                           int32_t* layout_end, StringPiece edge_name, std::string* out_err) {
   if (padding.size() > 1) {
     std::stringstream err_stream;
     err_stream << "too many padding sections on " << edge_name << " border";
diff --git a/tools/aapt2/compile/Png.h b/tools/aapt2/compile/Png.h
index 7f8d923..a8b7dd1 100644
--- a/tools/aapt2/compile/Png.h
+++ b/tools/aapt2/compile/Png.h
@@ -59,7 +59,7 @@
  */
 class PngChunkFilter : public io::InputStream {
  public:
-  explicit PngChunkFilter(const android::StringPiece& data);
+  explicit PngChunkFilter(android::StringPiece data);
   virtual ~PngChunkFilter() = default;
 
   bool Next(const void** buffer, size_t* len) override;
diff --git a/tools/aapt2/compile/PngChunkFilter.cpp b/tools/aapt2/compile/PngChunkFilter.cpp
index 4db2392..2e55d0c 100644
--- a/tools/aapt2/compile/PngChunkFilter.cpp
+++ b/tools/aapt2/compile/PngChunkFilter.cpp
@@ -70,7 +70,7 @@
   }
 }
 
-PngChunkFilter::PngChunkFilter(const StringPiece& data) : data_(data) {
+PngChunkFilter::PngChunkFilter(StringPiece data) : data_(data) {
   if (util::StartsWith(data_, kPngSignature)) {
     window_start_ = 0;
     window_end_ = kPngSignatureSize;
diff --git a/tools/aapt2/compile/Pseudolocalizer.cpp b/tools/aapt2/compile/Pseudolocalizer.cpp
index 3a515fa..463ce78 100644
--- a/tools/aapt2/compile/Pseudolocalizer.cpp
+++ b/tools/aapt2/compile/Pseudolocalizer.cpp
@@ -20,36 +20,42 @@
 
 using android::StringPiece;
 
+using namespace std::literals;
+
 namespace aapt {
 
 // String basis to generate expansion
-static const std::string kExpansionString =
+static constexpr auto kExpansionString =
     "one two three "
     "four five six seven eight nine ten eleven twelve thirteen "
-    "fourteen fiveteen sixteen seventeen nineteen twenty";
+    "fourteen fiveteen sixteen seventeen nineteen twenty"sv;
 
 // Special unicode characters to override directionality of the words
-static const std::string kRlm = "\u200f";
-static const std::string kRlo = "\u202e";
-static const std::string kPdf = "\u202c";
+static constexpr auto kRlm = "\u200f"sv;
+static constexpr auto kRlo = "\u202e"sv;
+static constexpr auto kPdf = "\u202c"sv;
 
 // Placeholder marks
-static const std::string kPlaceholderOpen = "\u00bb";
-static const std::string kPlaceholderClose = "\u00ab";
+static constexpr auto kPlaceholderOpen = "\u00bb"sv;
+static constexpr auto kPlaceholderClose = "\u00ab"sv;
 
 static const char kArgStart = '{';
 static const char kArgEnd = '}';
 
 class PseudoMethodNone : public PseudoMethodImpl {
  public:
-  std::string Text(const StringPiece& text) override { return text.to_string(); }
-  std::string Placeholder(const StringPiece& text) override { return text.to_string(); }
+  std::string Text(StringPiece text) override {
+    return std::string(text);
+  }
+  std::string Placeholder(StringPiece text) override {
+    return std::string(text);
+  }
 };
 
 class PseudoMethodBidi : public PseudoMethodImpl {
  public:
-  std::string Text(const StringPiece& text) override;
-  std::string Placeholder(const StringPiece& text) override;
+  std::string Text(StringPiece text) override;
+  std::string Placeholder(StringPiece text) override;
 };
 
 class PseudoMethodAccent : public PseudoMethodImpl {
@@ -57,8 +63,8 @@
   PseudoMethodAccent() : depth_(0), word_count_(0), length_(0) {}
   std::string Start() override;
   std::string End() override;
-  std::string Text(const StringPiece& text) override;
-  std::string Placeholder(const StringPiece& text) override;
+  std::string Text(StringPiece text) override;
+  std::string Placeholder(StringPiece text) override;
 
  private:
   size_t depth_;
@@ -84,7 +90,7 @@
   }
 }
 
-std::string Pseudolocalizer::Text(const StringPiece& text) {
+std::string Pseudolocalizer::Text(StringPiece text) {
   std::string out;
   size_t depth = last_depth_;
   size_t lastpos, pos;
@@ -116,7 +122,7 @@
       }
       size_t size = nextpos - lastpos;
       if (size) {
-        std::string chunk = text.substr(lastpos, size).to_string();
+        std::string chunk(text.substr(lastpos, size));
         if (pseudo) {
           chunk = impl_->Text(chunk);
         } else if (str[lastpos] == kArgStart && str[nextpos - 1] == kArgEnd) {
@@ -301,21 +307,23 @@
 }
 
 static std::string PseudoGenerateExpansion(const unsigned int length) {
-  std::string result = kExpansionString;
-  const char* s = result.data();
+  std::string result(kExpansionString);
   if (result.size() < length) {
     result += " ";
     result += PseudoGenerateExpansion(length - result.size());
   } else {
     int ext = 0;
     // Should contain only whole words, so looking for a space
-    for (unsigned int i = length + 1; i < result.size(); ++i) {
-      ++ext;
-      if (s[i] == ' ') {
-        break;
+    {
+      const char* const s = result.data();
+      for (unsigned int i = length + 1; i < result.size(); ++i) {
+        ++ext;
+        if (s[i] == ' ') {
+          break;
+        }
       }
     }
-    result = result.substr(0, length + ext);
+    result.resize(length + ext);
   }
   return result;
 }
@@ -349,7 +357,7 @@
  *
  * Note: This leaves placeholder syntax untouched.
  */
-std::string PseudoMethodAccent::Text(const StringPiece& source) {
+std::string PseudoMethodAccent::Text(StringPiece source) {
   const char* s = source.data();
   std::string result;
   const size_t I = source.size();
@@ -435,12 +443,12 @@
   return result;
 }
 
-std::string PseudoMethodAccent::Placeholder(const StringPiece& source) {
+std::string PseudoMethodAccent::Placeholder(StringPiece source) {
   // Surround a placeholder with brackets
-  return kPlaceholderOpen + source.to_string() + kPlaceholderClose;
+  return (std::string(kPlaceholderOpen) += source) += kPlaceholderClose;
 }
 
-std::string PseudoMethodBidi::Text(const StringPiece& source) {
+std::string PseudoMethodBidi::Text(StringPiece source) {
   const char* s = source.data();
   std::string result;
   bool lastspace = true;
@@ -456,10 +464,10 @@
     space = (!escape && isspace(c)) || (escape && (c == 'n' || c == 't'));
     if (lastspace && !space) {
       // Word start
-      result += kRlm + kRlo;
+      (result += kRlm) += kRlo;
     } else if (!lastspace && space) {
       // Word end
-      result += kPdf + kRlm;
+      (result += kPdf) += kRlm;
     }
     lastspace = space;
     if (escape) {
@@ -470,14 +478,14 @@
   }
   if (!lastspace) {
     // End of last word
-    result += kPdf + kRlm;
+    (result += kPdf) += kRlm;
   }
   return result;
 }
 
-std::string PseudoMethodBidi::Placeholder(const StringPiece& source) {
+std::string PseudoMethodBidi::Placeholder(StringPiece source) {
   // Surround a placeholder with directionality change sequence
-  return kRlm + kRlo + source.to_string() + kPdf + kRlm;
+  return (((std::string(kRlm) += kRlo) += source) += kPdf) += kRlm;
 }
 
 }  // namespace aapt
diff --git a/tools/aapt2/compile/Pseudolocalizer.h b/tools/aapt2/compile/Pseudolocalizer.h
index 4dedc70..2b94bcc 100644
--- a/tools/aapt2/compile/Pseudolocalizer.h
+++ b/tools/aapt2/compile/Pseudolocalizer.h
@@ -31,8 +31,8 @@
   virtual ~PseudoMethodImpl() {}
   virtual std::string Start() { return {}; }
   virtual std::string End() { return {}; }
-  virtual std::string Text(const android::StringPiece& text) = 0;
-  virtual std::string Placeholder(const android::StringPiece& text) = 0;
+  virtual std::string Text(android::StringPiece text) = 0;
+  virtual std::string Placeholder(android::StringPiece text) = 0;
 };
 
 class Pseudolocalizer {
@@ -47,7 +47,7 @@
   void SetMethod(Method method);
   std::string Start() { return impl_->Start(); }
   std::string End() { return impl_->End(); }
-  std::string Text(const android::StringPiece& text);
+  std::string Text(android::StringPiece text);
 
  private:
   std::unique_ptr<PseudoMethodImpl> impl_;
diff --git a/tools/aapt2/configuration/ConfigurationParser.cpp b/tools/aapt2/configuration/ConfigurationParser.cpp
index 6bba11e..1b03253 100644
--- a/tools/aapt2/configuration/ConfigurationParser.cpp
+++ b/tools/aapt2/configuration/ConfigurationParser.cpp
@@ -152,7 +152,7 @@
  * success, or false if the either the placeholder is not found in the name, or the value is not
  * present and the placeholder was.
  */
-bool ReplacePlaceholder(const StringPiece& placeholder, const std::optional<StringPiece>& value,
+bool ReplacePlaceholder(StringPiece placeholder, const std::optional<StringPiece>& value,
                         std::string* name, android::IDiagnostics* diag) {
   size_t offset = name->find(placeholder.data());
   bool found = (offset != std::string::npos);
@@ -338,17 +338,17 @@
   return {config};
 }
 
-const StringPiece& AbiToString(Abi abi) {
+StringPiece AbiToString(Abi abi) {
   return kAbiToStringMap.at(static_cast<size_t>(abi));
 }
 
 /**
  * Returns the common artifact base name from a template string.
  */
-std::optional<std::string> ToBaseName(std::string result, const StringPiece& apk_name,
+std::optional<std::string> ToBaseName(std::string result, StringPiece apk_name,
                                       android::IDiagnostics* diag) {
   const StringPiece ext = file::GetExtension(apk_name);
-  size_t end_index = apk_name.to_string().rfind(ext.to_string());
+  size_t end_index = apk_name.rfind(ext);
   const std::string base_name =
       (end_index != std::string::npos) ? std::string{apk_name.begin(), end_index} : "";
 
@@ -371,17 +371,17 @@
     // If no extension is specified, and the name template does not end in the current extension,
     // add the existing extension.
     if (!util::EndsWith(result, ext)) {
-      result.append(ext.to_string());
+      result.append(ext);
     }
   }
 
   return result;
 }
 
-std::optional<std::string> ConfiguredArtifact::ToArtifactName(const StringPiece& format,
-                                                              const StringPiece& apk_name,
+std::optional<std::string> ConfiguredArtifact::ToArtifactName(StringPiece format,
+                                                              StringPiece apk_name,
                                                               android::IDiagnostics* diag) const {
-  std::optional<std::string> base = ToBaseName(format.to_string(), apk_name, diag);
+  std::optional<std::string> base = ToBaseName(std::string(format), apk_name, diag);
   if (!base) {
     return {};
   }
@@ -414,7 +414,7 @@
   return result;
 }
 
-std::optional<std::string> ConfiguredArtifact::Name(const StringPiece& apk_name,
+std::optional<std::string> ConfiguredArtifact::Name(StringPiece apk_name,
                                                     android::IDiagnostics* diag) const {
   if (!name) {
     return {};
@@ -439,7 +439,7 @@
 }
 
 std::optional<std::vector<OutputArtifact>> ConfigurationParser::Parse(
-    const android::StringPiece& apk_path) {
+    android::StringPiece apk_path) {
   std::optional<PostProcessingConfiguration> maybe_config =
       ExtractConfiguration(contents_, config_path_, diag_);
   if (!maybe_config) {
@@ -447,7 +447,7 @@
   }
 
   // Convert from a parsed configuration to a list of artifacts for processing.
-  const std::string& apk_name = file::GetFilename(apk_path).to_string();
+  const std::string apk_name(file::GetFilename(apk_path));
   std::vector<OutputArtifact> output_artifacts;
 
   PostProcessingConfiguration& config = maybe_config.value();
@@ -519,7 +519,7 @@
   for (auto& node : root_element->children) {
     xml::Text* t;
     if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
-      config->artifact_format = TrimWhitespace(t->text).to_string();
+      config->artifact_format.emplace(TrimWhitespace(t->text));
       break;
     }
   }
@@ -561,7 +561,7 @@
       for (auto& node : child->children) {
         xml::Text* t;
         if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
-          auto abi = kStringToAbiMap.find(TrimWhitespace(t->text).to_string());
+          auto abi = kStringToAbiMap.find(TrimWhitespace(t->text));
           if (abi != kStringToAbiMap.end()) {
             group.push_back(abi->second);
           } else {
@@ -622,7 +622,7 @@
         xml::Text* t;
         if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
           ConfigDescription config_descriptor;
-          const android::StringPiece& text = TrimWhitespace(t->text);
+          android::StringPiece text = TrimWhitespace(t->text);
           bool parsed = ConfigDescription::Parse(text, &config_descriptor);
           if (parsed &&
               (config_descriptor.CopyWithoutSdkVersion().diff(ConfigDescription::DefaultConfig()) ==
@@ -688,7 +688,7 @@
         xml::Text* t;
         if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
           ConfigDescription config_descriptor;
-          const android::StringPiece& text = TrimWhitespace(t->text);
+          android::StringPiece text = TrimWhitespace(t->text);
           bool parsed = ConfigDescription::Parse(text, &config_descriptor);
           if (parsed &&
               (config_descriptor.CopyWithoutSdkVersion().diff(ConfigDescription::DefaultConfig()) ==
@@ -806,7 +806,7 @@
         for (auto& node : element->children) {
           xml::Text* t;
           if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
-            result.texture_paths.push_back(TrimWhitespace(t->text).to_string());
+            result.texture_paths.emplace_back(TrimWhitespace(t->text));
           }
         }
       }
@@ -843,7 +843,7 @@
       for (auto& node : child->children) {
         xml::Text* t;
         if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
-          group.push_back(TrimWhitespace(t->text).to_string());
+          group.emplace_back(TrimWhitespace(t->text));
           break;
         }
       }
diff --git a/tools/aapt2/configuration/ConfigurationParser.h b/tools/aapt2/configuration/ConfigurationParser.h
index 2c8221d..d66f4ab 100644
--- a/tools/aapt2/configuration/ConfigurationParser.h
+++ b/tools/aapt2/configuration/ConfigurationParser.h
@@ -43,7 +43,7 @@
 };
 
 /** Helper method to convert an ABI to a string representing the path within the APK. */
-const android::StringPiece& AbiToString(Abi abi);
+android::StringPiece AbiToString(Abi abi);
 
 /**
  * Represents an individual locale. When a locale is included, it must be
@@ -150,8 +150,7 @@
    * Parses the configuration file and returns the results. If the configuration could not be parsed
    * the result is empty and any errors will be displayed with the provided diagnostics context.
    */
-  std::optional<std::vector<configuration::OutputArtifact>> Parse(
-      const android::StringPiece& apk_path);
+  std::optional<std::vector<configuration::OutputArtifact>> Parse(android::StringPiece apk_path);
 
  protected:
   /**
diff --git a/tools/aapt2/configuration/ConfigurationParser.internal.h b/tools/aapt2/configuration/ConfigurationParser.internal.h
index 3028c3f..198f730 100644
--- a/tools/aapt2/configuration/ConfigurationParser.internal.h
+++ b/tools/aapt2/configuration/ConfigurationParser.internal.h
@@ -138,13 +138,12 @@
   std::optional<std::string> gl_texture_group;
 
   /** Convert an artifact name template into a name string based on configuration contents. */
-  std::optional<std::string> ToArtifactName(const android::StringPiece& format,
-                                            const android::StringPiece& apk_name,
+  std::optional<std::string> ToArtifactName(android::StringPiece format,
+                                            android::StringPiece apk_name,
                                             android::IDiagnostics* diag) const;
 
   /** Convert an artifact name template into a name string based on configuration contents. */
-  std::optional<std::string> Name(const android::StringPiece& apk_name,
-                                  android::IDiagnostics* diag) const;
+  std::optional<std::string> Name(android::StringPiece apk_name, android::IDiagnostics* diag) const;
 };
 
 /** AAPT2 XML configuration file binary representation. */
diff --git a/tools/aapt2/filter/AbiFilter.cpp b/tools/aapt2/filter/AbiFilter.cpp
index 9ace82a..908b171 100644
--- a/tools/aapt2/filter/AbiFilter.cpp
+++ b/tools/aapt2/filter/AbiFilter.cpp
@@ -23,15 +23,15 @@
 namespace aapt {
 
 std::unique_ptr<AbiFilter> AbiFilter::FromAbiList(const std::vector<configuration::Abi>& abi_list) {
-  std::unordered_set<std::string> abi_set;
+  std::unordered_set<std::string_view> abi_set;
   for (auto& abi : abi_list) {
-    abi_set.insert(configuration::AbiToString(abi).to_string());
+    abi_set.insert(configuration::AbiToString(abi));
   }
   // Make unique by hand as the constructor is private.
-  return std::unique_ptr<AbiFilter>(new AbiFilter(abi_set));
+  return std::unique_ptr<AbiFilter>(new AbiFilter(std::move(abi_set)));
 }
 
-bool AbiFilter::Keep(const std::string& path) {
+bool AbiFilter::Keep(std::string_view path) {
   // We only care about libraries.
   if (!util::StartsWith(path, kLibPrefix)) {
     return true;
@@ -44,7 +44,7 @@
   }
 
   // Strip the lib/ prefix.
-  const std::string& path_abi = path.substr(kLibPrefixLen, abi_end - kLibPrefixLen);
+  const auto path_abi = path.substr(kLibPrefixLen, abi_end - kLibPrefixLen);
   return (abis_.find(path_abi) != abis_.end());
 }
 
diff --git a/tools/aapt2/filter/AbiFilter.h b/tools/aapt2/filter/AbiFilter.h
index 2832711..7380f3f 100644
--- a/tools/aapt2/filter/AbiFilter.h
+++ b/tools/aapt2/filter/AbiFilter.h
@@ -18,7 +18,7 @@
 #define AAPT2_ABISPLITTER_H
 
 #include <memory>
-#include <string>
+#include <string_view>
 #include <unordered_set>
 #include <vector>
 
@@ -39,16 +39,16 @@
   static std::unique_ptr<AbiFilter> FromAbiList(const std::vector<configuration::Abi>& abi_list);
 
   /** Returns true if the path is for a native library in the list of desired ABIs. */
-  bool Keep(const std::string& path) override;
+  bool Keep(std::string_view path) override;
 
  private:
-  explicit AbiFilter(std::unordered_set<std::string> abis) : abis_(std::move(abis)) {
+  explicit AbiFilter(std::unordered_set<std::string_view> abis) : abis_(std::move(abis)) {
   }
 
   /** The path prefix to where all native libs end up inside an APK file. */
   static constexpr const char* kLibPrefix = "lib/";
   static constexpr size_t kLibPrefixLen = 4;
-  const std::unordered_set<std::string> abis_;
+  const std::unordered_set<std::string_view> abis_;
 };
 
 }  // namespace aapt
diff --git a/tools/aapt2/filter/Filter.h b/tools/aapt2/filter/Filter.h
index f932f9c..baf4791 100644
--- a/tools/aapt2/filter/Filter.h
+++ b/tools/aapt2/filter/Filter.h
@@ -18,6 +18,7 @@
 #define AAPT2_FILTER_H
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "util/Util.h"
@@ -30,7 +31,7 @@
   virtual ~IPathFilter() = default;
 
   /** Returns true if the path should be kept. */
-  virtual bool Keep(const std::string& path) = 0;
+  virtual bool Keep(std::string_view path) = 0;
 };
 
 /**
@@ -42,7 +43,7 @@
   }
 
   /** Returns true if the provided path matches the prefix. */
-  bool Keep(const std::string& path) override {
+  bool Keep(std::string_view path) override {
     return util::StartsWith(path, prefix_);
   }
 
@@ -59,7 +60,7 @@
   }
 
   /** Returns true if all filters keep the path. */
-  bool Keep(const std::string& path) override {
+  bool Keep(std::string_view path) override {
     for (auto& filter : filters_) {
       if (!filter->Keep(path)) {
         return false;
diff --git a/tools/aapt2/format/Archive.cpp b/tools/aapt2/format/Archive.cpp
index 80c1618..e9a93d8 100644
--- a/tools/aapt2/format/Archive.cpp
+++ b/tools/aapt2/format/Archive.cpp
@@ -40,8 +40,8 @@
  public:
   DirectoryWriter() = default;
 
-  bool Open(const StringPiece& out_dir) {
-    dir_ = out_dir.to_string();
+  bool Open(StringPiece out_dir) {
+    dir_ = std::string(out_dir);
     file::FileType type = file::GetFileType(dir_);
     if (type == file::FileType::kNonExistant) {
       error_ = "directory does not exist";
@@ -53,14 +53,14 @@
     return true;
   }
 
-  bool StartEntry(const StringPiece& path, uint32_t flags) override {
+  bool StartEntry(StringPiece path, uint32_t flags) override {
     if (file_) {
       return false;
     }
 
     std::string full_path = dir_;
     file::AppendPath(&full_path, path);
-    file::mkdirs(file::GetStem(full_path).to_string());
+    file::mkdirs(std::string(file::GetStem(full_path)));
 
     file_ = {::android::base::utf8::fopen(full_path.c_str(), "wb"), fclose};
     if (!file_) {
@@ -91,7 +91,7 @@
     return true;
   }
 
-  bool WriteFile(const StringPiece& path, uint32_t flags, io::InputStream* in) override {
+  bool WriteFile(StringPiece path, uint32_t flags, io::InputStream* in) override {
     if (!StartEntry(path, flags)) {
       return false;
     }
@@ -132,8 +132,8 @@
  public:
   ZipFileWriter() = default;
 
-  bool Open(const StringPiece& path) {
-    file_ = {::android::base::utf8::fopen(path.to_string().c_str(), "w+b"), fclose};
+  bool Open(StringPiece path) {
+    file_ = {::android::base::utf8::fopen(path.data(), "w+b"), fclose};
     if (!file_) {
       error_ = SystemErrorCodeToString(errno);
       return false;
@@ -142,7 +142,7 @@
     return true;
   }
 
-  bool StartEntry(const StringPiece& path, uint32_t flags) override {
+  bool StartEntry(StringPiece path, uint32_t flags) override {
     if (!writer_) {
       return false;
     }
@@ -182,7 +182,7 @@
     return true;
   }
 
-  bool WriteFile(const StringPiece& path, uint32_t flags, io::InputStream* in) override {
+  bool WriteFile(StringPiece path, uint32_t flags, io::InputStream* in) override {
     while (true) {
       if (!StartEntry(path, flags)) {
         return false;
@@ -257,7 +257,7 @@
 }  // namespace
 
 std::unique_ptr<IArchiveWriter> CreateDirectoryArchiveWriter(android::IDiagnostics* diag,
-                                                             const StringPiece& path) {
+                                                             StringPiece path) {
   std::unique_ptr<DirectoryWriter> writer = util::make_unique<DirectoryWriter>();
   if (!writer->Open(path)) {
     diag->Error(android::DiagMessage(path) << writer->GetError());
@@ -267,7 +267,7 @@
 }
 
 std::unique_ptr<IArchiveWriter> CreateZipFileArchiveWriter(android::IDiagnostics* diag,
-                                                           const StringPiece& path) {
+                                                           StringPiece path) {
   std::unique_ptr<ZipFileWriter> writer = util::make_unique<ZipFileWriter>();
   if (!writer->Open(path)) {
     diag->Error(android::DiagMessage(path) << writer->GetError());
diff --git a/tools/aapt2/format/Archive.h b/tools/aapt2/format/Archive.h
index 55b0b2f..6cde753 100644
--- a/tools/aapt2/format/Archive.h
+++ b/tools/aapt2/format/Archive.h
@@ -46,12 +46,12 @@
  public:
   virtual ~IArchiveWriter() = default;
 
-  virtual bool WriteFile(const android::StringPiece& path, uint32_t flags, io::InputStream* in) = 0;
+  virtual bool WriteFile(android::StringPiece path, uint32_t flags, io::InputStream* in) = 0;
 
   // Starts a new entry and allows caller to write bytes to it sequentially.
   // Only use StartEntry if code you do not control needs to write to a CopyingOutputStream.
   // Prefer WriteFile instead of manually calling StartEntry/FinishEntry.
-  virtual bool StartEntry(const android::StringPiece& path, uint32_t flags) = 0;
+  virtual bool StartEntry(android::StringPiece path, uint32_t flags) = 0;
 
   // Called to finish writing an entry previously started by StartEntry.
   // Prefer WriteFile instead of manually calling StartEntry/FinishEntry.
@@ -70,10 +70,10 @@
 };
 
 std::unique_ptr<IArchiveWriter> CreateDirectoryArchiveWriter(android::IDiagnostics* diag,
-                                                             const android::StringPiece& path);
+                                                             android::StringPiece path);
 
 std::unique_ptr<IArchiveWriter> CreateZipFileArchiveWriter(android::IDiagnostics* diag,
-                                                           const android::StringPiece& path);
+                                                           android::StringPiece path);
 
 }  // namespace aapt
 
diff --git a/tools/aapt2/format/Archive_test.cpp b/tools/aapt2/format/Archive_test.cpp
index ceed374..3c44da7 100644
--- a/tools/aapt2/format/Archive_test.cpp
+++ b/tools/aapt2/format/Archive_test.cpp
@@ -50,7 +50,7 @@
 }
 
 std::unique_ptr<IArchiveWriter> MakeZipFileWriter(const std::string& output_path) {
-  file::mkdirs(file::GetStem(output_path).to_string());
+  file::mkdirs(std::string(file::GetStem(output_path)));
   std::remove(output_path.c_str());
 
   StdErrDiagnostics diag;
diff --git a/tools/aapt2/format/binary/BinaryResourceParser.cpp b/tools/aapt2/format/binary/BinaryResourceParser.cpp
index 8291862..75dcba5 100644
--- a/tools/aapt2/format/binary/BinaryResourceParser.cpp
+++ b/tools/aapt2/format/binary/BinaryResourceParser.cpp
@@ -373,7 +373,7 @@
   std::optional<ResourceNamedTypeRef> parsed_type = ParseResourceNamedType(type_str);
   if (!parsed_type) {
     diag_->Warn(android::DiagMessage(source_)
-                << "invalid type name '" << type_str << "' for type with ID " << type->id);
+                << "invalid type name '" << type_str << "' for type with ID " << int(type->id));
     return true;
   }
 
diff --git a/tools/aapt2/format/binary/TableFlattener_test.cpp b/tools/aapt2/format/binary/TableFlattener_test.cpp
index d08b4a3..0f11685 100644
--- a/tools/aapt2/format/binary/TableFlattener_test.cpp
+++ b/tools/aapt2/format/binary/TableFlattener_test.cpp
@@ -84,7 +84,7 @@
     return ::testing::AssertionSuccess();
   }
 
-  ::testing::AssertionResult Exists(ResTable* table, const StringPiece& expected_name,
+  ::testing::AssertionResult Exists(ResTable* table, StringPiece expected_name,
                                     const ResourceId& expected_id,
                                     const ConfigDescription& expected_config,
                                     const uint8_t expected_data_type, const uint32_t expected_data,
diff --git a/tools/aapt2/format/binary/XmlFlattener.cpp b/tools/aapt2/format/binary/XmlFlattener.cpp
index 983e646..05f9751 100644
--- a/tools/aapt2/format/binary/XmlFlattener.cpp
+++ b/tools/aapt2/format/binary/XmlFlattener.cpp
@@ -79,7 +79,7 @@
   }
 
   void Visit(const xml::Text* node) override {
-    std::string text = util::TrimWhitespace(node->text).to_string();
+    std::string text(util::TrimWhitespace(node->text));
 
     // Skip whitespace only text nodes.
     if (text.empty()) {
@@ -88,10 +88,10 @@
 
     // Compact leading and trailing whitespace into a single space
     if (isspace(node->text[0])) {
-      text = ' ' + text;
+      text.insert(text.begin(), ' ');
     }
-    if (isspace(node->text[node->text.length() - 1])) {
-      text = text + ' ';
+    if (isspace(node->text.back())) {
+      text += ' ';
     }
 
     ChunkWriter writer(buffer_);
@@ -165,7 +165,7 @@
   // We are adding strings to a StringPool whose strings will be sorted and merged with other
   // string pools. That means we can't encode the ID of a string directly. Instead, we defer the
   // writing of the ID here, until after the StringPool is merged and sorted.
-  void AddString(const StringPiece& str, uint32_t priority, android::ResStringPool_ref* dest,
+  void AddString(StringPiece str, uint32_t priority, android::ResStringPool_ref* dest,
                  bool treat_empty_string_as_null = false) {
     if (str.empty() && treat_empty_string_as_null) {
       // Some parts of the runtime treat null differently than empty string.
diff --git a/tools/aapt2/format/proto/ProtoSerialize_test.cpp b/tools/aapt2/format/proto/ProtoSerialize_test.cpp
index 5adc5e6..ecfdba8 100644
--- a/tools/aapt2/format/proto/ProtoSerialize_test.cpp
+++ b/tools/aapt2/format/proto/ProtoSerialize_test.cpp
@@ -35,7 +35,7 @@
 
 class MockFileCollection : public io::IFileCollection {
  public:
-  MOCK_METHOD1(FindFile, io::IFile*(const StringPiece& path));
+  MOCK_METHOD1(FindFile, io::IFile*(StringPiece path));
   MOCK_METHOD0(Iterator, std::unique_ptr<io::IFileCollectionIterator>());
   MOCK_METHOD0(GetDirSeparator, char());
 };
@@ -491,7 +491,7 @@
   EXPECT_THAT(bp->value.data, Eq(ResourceUtils::MakeEmpty()->value.data));
 }
 
-static void ExpectConfigSerializes(const StringPiece& config_str) {
+static void ExpectConfigSerializes(StringPiece config_str) {
   const ConfigDescription expected_config = test::ParseConfigOrDie(config_str);
   pb::Configuration pb_config;
   SerializeConfig(expected_config, &pb_config);
diff --git a/tools/aapt2/io/File.h b/tools/aapt2/io/File.h
index 422658a..08d497d 100644
--- a/tools/aapt2/io/File.h
+++ b/tools/aapt2/io/File.h
@@ -101,7 +101,7 @@
  public:
   virtual ~IFileCollection() = default;
 
-  virtual IFile* FindFile(const android::StringPiece& path) = 0;
+  virtual IFile* FindFile(android::StringPiece path) = 0;
   virtual std::unique_ptr<IFileCollectionIterator> Iterator() = 0;
   virtual char GetDirSeparator() = 0;
 };
diff --git a/tools/aapt2/io/FileSystem.cpp b/tools/aapt2/io/FileSystem.cpp
index 3f071af..a64982a 100644
--- a/tools/aapt2/io/FileSystem.cpp
+++ b/tools/aapt2/io/FileSystem.cpp
@@ -67,8 +67,8 @@
   return result;
 }
 
-std::unique_ptr<FileCollection> FileCollection::Create(const android::StringPiece& root,
-                                                        std::string* outError) {
+std::unique_ptr<FileCollection> FileCollection::Create(android::StringPiece root,
+                                                       std::string* outError) {
   std::unique_ptr<FileCollection> collection =
       std::unique_ptr<FileCollection>(new FileCollection());
 
@@ -80,7 +80,7 @@
 
   std::vector<std::string> sorted_files;
   while (struct dirent *entry = readdir(d.get())) {
-    std::string prefix_path = root.to_string();
+    std::string prefix_path(root);
     file::AppendPath(&prefix_path, entry->d_name);
 
     // The directory to iterate over looking for files
@@ -117,12 +117,19 @@
   return collection;
 }
 
-IFile* FileCollection::InsertFile(const StringPiece& path) {
-  return (files_[path.to_string()] = util::make_unique<RegularFile>(android::Source(path))).get();
+IFile* FileCollection::InsertFile(StringPiece path) {
+  auto file = util::make_unique<RegularFile>(android::Source(path));
+  auto it = files_.lower_bound(path);
+  if (it != files_.end() && it->first == path) {
+    it->second = std::move(file);
+  } else {
+    it = files_.emplace_hint(it, path, std::move(file));
+  }
+  return it->second.get();
 }
 
-IFile* FileCollection::FindFile(const StringPiece& path) {
-  auto iter = files_.find(path.to_string());
+IFile* FileCollection::FindFile(StringPiece path) {
+  auto iter = files_.find(path);
   if (iter != files_.end()) {
     return iter->second.get();
   }
diff --git a/tools/aapt2/io/FileSystem.h b/tools/aapt2/io/FileSystem.h
index bc03b9b..0e798fc 100644
--- a/tools/aapt2/io/FileSystem.h
+++ b/tools/aapt2/io/FileSystem.h
@@ -60,12 +60,11 @@
   FileCollection() = default;
 
   /** Creates a file collection containing all files contained in the specified root directory. */
-  static std::unique_ptr<FileCollection> Create(const android::StringPiece& path,
-                                                std::string* outError);
+  static std::unique_ptr<FileCollection> Create(android::StringPiece path, std::string* outError);
 
   // Adds a file located at path. Returns the IFile representation of that file.
-  IFile* InsertFile(const android::StringPiece& path);
-  IFile* FindFile(const android::StringPiece& path) override;
+  IFile* InsertFile(android::StringPiece path);
+  IFile* FindFile(android::StringPiece path) override;
   std::unique_ptr<IFileCollectionIterator> Iterator() override;
   char GetDirSeparator() override;
 
@@ -74,7 +73,7 @@
 
   friend class FileCollectionIterator;
 
-  std::map<std::string, std::unique_ptr<IFile>> files_;
+  std::map<std::string, std::unique_ptr<IFile>, std::less<>> files_;
 };
 
 }  // namespace io
diff --git a/tools/aapt2/io/StringStream.cpp b/tools/aapt2/io/StringStream.cpp
index 4ca04a8..9c49788 100644
--- a/tools/aapt2/io/StringStream.cpp
+++ b/tools/aapt2/io/StringStream.cpp
@@ -21,7 +21,7 @@
 namespace aapt {
 namespace io {
 
-StringInputStream::StringInputStream(const StringPiece& str) : str_(str), offset_(0u) {
+StringInputStream::StringInputStream(StringPiece str) : str_(str), offset_(0u) {
 }
 
 bool StringInputStream::Next(const void** data, size_t* size) {
diff --git a/tools/aapt2/io/StringStream.h b/tools/aapt2/io/StringStream.h
index f29890a..f7bdecca 100644
--- a/tools/aapt2/io/StringStream.h
+++ b/tools/aapt2/io/StringStream.h
@@ -29,7 +29,7 @@
 
 class StringInputStream : public KnownSizeInputStream {
  public:
-  explicit StringInputStream(const android::StringPiece& str);
+  explicit StringInputStream(android::StringPiece str);
 
   bool Next(const void** data, size_t* size) override;
 
diff --git a/tools/aapt2/io/Util.cpp b/tools/aapt2/io/Util.cpp
index afe54d4..79d8d52 100644
--- a/tools/aapt2/io/Util.cpp
+++ b/tools/aapt2/io/Util.cpp
@@ -26,7 +26,7 @@
 namespace aapt {
 namespace io {
 
-bool CopyInputStreamToArchive(IAaptContext* context, InputStream* in, const std::string& out_path,
+bool CopyInputStreamToArchive(IAaptContext* context, InputStream* in, std::string_view out_path,
                               uint32_t compression_flags, IArchiveWriter* writer) {
   TRACE_CALL();
   if (context->IsVerbose()) {
@@ -43,7 +43,7 @@
   return true;
 }
 
-bool CopyFileToArchive(IAaptContext* context, io::IFile* file, const std::string& out_path,
+bool CopyFileToArchive(IAaptContext* context, io::IFile* file, std::string_view out_path,
                        uint32_t compression_flags, IArchiveWriter* writer) {
   TRACE_CALL();
   std::unique_ptr<io::IData> data = file->OpenAsData();
@@ -56,13 +56,13 @@
 }
 
 bool CopyFileToArchivePreserveCompression(IAaptContext* context, io::IFile* file,
-                                          const std::string& out_path, IArchiveWriter* writer) {
+                                          std::string_view out_path, IArchiveWriter* writer) {
   uint32_t compression_flags = file->WasCompressed() ? ArchiveEntry::kCompress : 0u;
   return CopyFileToArchive(context, file, out_path, compression_flags, writer);
 }
 
 bool CopyProtoToArchive(IAaptContext* context, ::google::protobuf::Message* proto_msg,
-                        const std::string& out_path, uint32_t compression_flags,
+                        std::string_view out_path, uint32_t compression_flags,
                         IArchiveWriter* writer) {
   TRACE_CALL();
   if (context->IsVerbose()) {
@@ -110,7 +110,7 @@
   return !in->HadError();
 }
 
-bool Copy(OutputStream* out, const StringPiece& in) {
+bool Copy(OutputStream* out, StringPiece in) {
   const char* in_buffer = in.data();
   size_t in_len = in.size();
   while (in_len != 0) {
diff --git a/tools/aapt2/io/Util.h b/tools/aapt2/io/Util.h
index 1b48a28..685f522 100644
--- a/tools/aapt2/io/Util.h
+++ b/tools/aapt2/io/Util.h
@@ -17,12 +17,11 @@
 #ifndef AAPT_IO_UTIL_H
 #define AAPT_IO_UTIL_H
 
-#include <string>
-
-#include "google/protobuf/message.h"
-#include "google/protobuf/io/coded_stream.h"
+#include <string_view>
 
 #include "format/Archive.h"
+#include "google/protobuf/io/coded_stream.h"
+#include "google/protobuf/message.h"
 #include "io/File.h"
 #include "io/Io.h"
 #include "process/IResourceTableConsumer.h"
@@ -30,23 +29,23 @@
 namespace aapt {
 namespace io {
 
-bool CopyInputStreamToArchive(IAaptContext* context, InputStream* in, const std::string& out_path,
+bool CopyInputStreamToArchive(IAaptContext* context, InputStream* in, std::string_view out_path,
                               uint32_t compression_flags, IArchiveWriter* writer);
 
-bool CopyFileToArchive(IAaptContext* context, IFile* file, const std::string& out_path,
+bool CopyFileToArchive(IAaptContext* context, IFile* file, std::string_view out_path,
                        uint32_t compression_flags, IArchiveWriter* writer);
 
 bool CopyFileToArchivePreserveCompression(IAaptContext* context, IFile* file,
-                                          const std::string& out_path, IArchiveWriter* writer);
+                                          std::string_view out_path, IArchiveWriter* writer);
 
 bool CopyProtoToArchive(IAaptContext* context, ::google::protobuf::Message* proto_msg,
-                        const std::string& out_path, uint32_t compression_flags,
+                        std::string_view out_path, uint32_t compression_flags,
                         IArchiveWriter* writer);
 
 // Copies the data from in to out. Returns false if there was an error.
 // If there was an error, check the individual streams' HadError/GetError methods.
 bool Copy(OutputStream* out, InputStream* in);
-bool Copy(OutputStream* out, const ::android::StringPiece& in);
+bool Copy(OutputStream* out, android::StringPiece in);
 bool Copy(::google::protobuf::io::ZeroCopyOutputStream* out, InputStream* in);
 
 class OutputStreamAdaptor : public io::OutputStream {
diff --git a/tools/aapt2/io/ZipArchive.cpp b/tools/aapt2/io/ZipArchive.cpp
index 400269c..4a5385d 100644
--- a/tools/aapt2/io/ZipArchive.cpp
+++ b/tools/aapt2/io/ZipArchive.cpp
@@ -91,8 +91,8 @@
 
 ZipFileCollection::ZipFileCollection() : handle_(nullptr) {}
 
-std::unique_ptr<ZipFileCollection> ZipFileCollection::Create(
-    const StringPiece& path, std::string* out_error) {
+std::unique_ptr<ZipFileCollection> ZipFileCollection::Create(StringPiece path,
+                                                             std::string* out_error) {
   TRACE_CALL();
   constexpr static const int32_t kEmptyArchive = -6;
 
@@ -130,8 +130,8 @@
       continue;
     }
 
-    std::unique_ptr<IFile> file = util::make_unique<ZipFile>(
-        collection->handle_, zip_data, android::Source(zip_entry_path, path.to_string()));
+    std::unique_ptr<IFile> file = util::make_unique<ZipFile>(collection->handle_, zip_data,
+                                                             android::Source(zip_entry_path, path));
     collection->files_by_name_[zip_entry_path] = file.get();
     collection->files_.push_back(std::move(file));
   }
@@ -144,8 +144,8 @@
   return collection;
 }
 
-IFile* ZipFileCollection::FindFile(const StringPiece& path) {
-  auto iter = files_by_name_.find(path.to_string());
+IFile* ZipFileCollection::FindFile(StringPiece path) {
+  auto iter = files_by_name_.find(path);
   if (iter != files_by_name_.end()) {
     return iter->second;
   }
diff --git a/tools/aapt2/io/ZipArchive.h b/tools/aapt2/io/ZipArchive.h
index 78c9c21..c263aa4 100644
--- a/tools/aapt2/io/ZipArchive.h
+++ b/tools/aapt2/io/ZipArchive.h
@@ -61,10 +61,10 @@
 // An IFileCollection that represents a ZIP archive and the entries within it.
 class ZipFileCollection : public IFileCollection {
  public:
-  static std::unique_ptr<ZipFileCollection> Create(const android::StringPiece& path,
+  static std::unique_ptr<ZipFileCollection> Create(android::StringPiece path,
                                                    std::string* outError);
 
-  io::IFile* FindFile(const android::StringPiece& path) override;
+  io::IFile* FindFile(android::StringPiece path) override;
   std::unique_ptr<IFileCollectionIterator> Iterator() override;
   char GetDirSeparator() override;
 
@@ -76,7 +76,7 @@
 
   ZipArchiveHandle handle_;
   std::vector<std::unique_ptr<IFile>> files_;
-  std::map<std::string, IFile*> files_by_name_;
+  std::map<std::string, IFile*, std::less<>> files_by_name_;
 };
 
 }  // namespace io
diff --git a/tools/aapt2/java/AnnotationProcessor.cpp b/tools/aapt2/java/AnnotationProcessor.cpp
index 482d91a..87da09a 100644
--- a/tools/aapt2/java/AnnotationProcessor.cpp
+++ b/tools/aapt2/java/AnnotationProcessor.cpp
@@ -30,7 +30,7 @@
 
 namespace aapt {
 
-StringPiece AnnotationProcessor::ExtractFirstSentence(const StringPiece& comment) {
+StringPiece AnnotationProcessor::ExtractFirstSentence(StringPiece comment) {
   Utf8Iterator iter(comment);
   while (iter.HasNext()) {
     const char32_t codepoint = iter.Next();
@@ -62,7 +62,7 @@
 }};
 
 void AnnotationProcessor::AppendCommentLine(std::string comment) {
-  static const std::string sDeprecated = "@deprecated";
+  static constexpr std::string_view sDeprecated = "@deprecated";
 
   // Treat deprecated specially, since we don't remove it from the source comment.
   if (comment.find(sDeprecated) != std::string::npos) {
@@ -74,7 +74,7 @@
     if (idx != std::string::npos) {
       // Captures all parameters associated with the specified annotation rule
       // by matching the first pair of parantheses after the rule.
-      std::regex re(rule.doc_str.to_string() + "\\s*\\((.+)\\)");
+      std::regex re(std::string(rule.doc_str) += "\\s*\\((.+)\\)");
       std::smatch match_result;
       const bool is_match = std::regex_search(comment, match_result, re);
       // We currently only capture and preserve parameters for SystemApi.
@@ -97,7 +97,7 @@
 
   // If there was trimming to do, copy the string.
   if (trimmed.size() != comment.size()) {
-    comment = trimmed.to_string();
+    comment = std::string(trimmed);
   }
 
   if (!has_comments_) {
@@ -107,12 +107,12 @@
   comment_ << "\n * " << std::move(comment);
 }
 
-void AnnotationProcessor::AppendComment(const StringPiece& comment) {
+void AnnotationProcessor::AppendComment(StringPiece comment) {
   // We need to process line by line to clean-up whitespace and append prefixes.
   for (StringPiece line : util::Tokenize(comment, '\n')) {
     line = util::TrimWhitespace(line);
     if (!line.empty()) {
-      AppendCommentLine(line.to_string());
+      AppendCommentLine(std::string(line));
     }
   }
 }
@@ -126,7 +126,7 @@
 void AnnotationProcessor::Print(Printer* printer, bool strip_api_annotations) const {
   if (has_comments_) {
     std::string result = comment_.str();
-    for (const StringPiece& line : util::Tokenize(result, '\n')) {
+    for (StringPiece line : util::Tokenize(result, '\n')) {
       printer->Println(line);
     }
     printer->Println(" */");
diff --git a/tools/aapt2/java/AnnotationProcessor.h b/tools/aapt2/java/AnnotationProcessor.h
index f217afb..db3437e 100644
--- a/tools/aapt2/java/AnnotationProcessor.h
+++ b/tools/aapt2/java/AnnotationProcessor.h
@@ -56,11 +56,11 @@
   // Extracts the first sentence of a comment. The algorithm selects the substring starting from
   // the beginning of the string, and ending at the first '.' character that is followed by a
   // whitespace character. If these requirements are not met, the whole string is returned.
-  static android::StringPiece ExtractFirstSentence(const android::StringPiece& comment);
+  static android::StringPiece ExtractFirstSentence(android::StringPiece comment);
 
   // Adds more comments. Resources can have value definitions for various configurations, and
   // each of the definitions may have comments that need to be processed.
-  void AppendComment(const android::StringPiece& comment);
+  void AppendComment(android::StringPiece comment);
 
   void AppendNewLine();
 
diff --git a/tools/aapt2/java/ClassDefinition.cpp b/tools/aapt2/java/ClassDefinition.cpp
index 3163497..98f3bd2 100644
--- a/tools/aapt2/java/ClassDefinition.cpp
+++ b/tools/aapt2/java/ClassDefinition.cpp
@@ -27,8 +27,8 @@
   processor_.Print(printer, strip_api_annotations);
 }
 
-void MethodDefinition::AppendStatement(const StringPiece& statement) {
-  statements_.push_back(statement.to_string());
+void MethodDefinition::AppendStatement(StringPiece statement) {
+  statements_.emplace_back(statement);
 }
 
 void MethodDefinition::Print(bool final, Printer* printer, bool) const {
@@ -110,8 +110,8 @@
     " * should not be modified by hand.\n"
     " */\n\n";
 
-void ClassDefinition::WriteJavaFile(const ClassDefinition* def, const StringPiece& package,
-                                    bool final, bool strip_api_annotations, io::OutputStream* out) {
+void ClassDefinition::WriteJavaFile(const ClassDefinition* def, StringPiece package, bool final,
+                                    bool strip_api_annotations, io::OutputStream* out) {
   Printer printer(out);
   printer.Print(sWarningHeader).Print("package ").Print(package).Println(";");
   printer.Println();
diff --git a/tools/aapt2/java/ClassDefinition.h b/tools/aapt2/java/ClassDefinition.h
index 2acdadb..63c9982 100644
--- a/tools/aapt2/java/ClassDefinition.h
+++ b/tools/aapt2/java/ClassDefinition.h
@@ -59,8 +59,8 @@
 template <typename T>
 class PrimitiveMember : public ClassMember {
  public:
-  PrimitiveMember(const android::StringPiece& name, const T& val, bool staged_api = false)
-      : name_(name.to_string()), val_(val), staged_api_(staged_api) {
+  PrimitiveMember(android::StringPiece name, const T& val, bool staged_api = false)
+      : name_(name), val_(val), staged_api_(staged_api) {
   }
 
   bool empty() const override {
@@ -104,8 +104,8 @@
 template <>
 class PrimitiveMember<std::string> : public ClassMember {
  public:
-  PrimitiveMember(const android::StringPiece& name, const std::string& val, bool staged_api = false)
-      : name_(name.to_string()), val_(val) {
+  PrimitiveMember(android::StringPiece name, const std::string& val, bool staged_api = false)
+      : name_(name), val_(val) {
   }
 
   bool empty() const override {
@@ -141,7 +141,8 @@
 template <typename T, typename StringConverter>
 class PrimitiveArrayMember : public ClassMember {
  public:
-  explicit PrimitiveArrayMember(const android::StringPiece& name) : name_(name.to_string()) {}
+  explicit PrimitiveArrayMember(android::StringPiece name) : name_(name) {
+  }
 
   void AddElement(const T& val) {
     elements_.emplace_back(val);
@@ -209,12 +210,12 @@
 class MethodDefinition : public ClassMember {
  public:
   // Expected method signature example: 'public static void onResourcesLoaded(int p)'.
-  explicit MethodDefinition(const android::StringPiece& signature)
-      : signature_(signature.to_string()) {}
+  explicit MethodDefinition(android::StringPiece signature) : signature_(signature) {
+  }
 
   // Appends a single statement to the method. It should include no newlines or else
   // formatting may be broken.
-  void AppendStatement(const android::StringPiece& statement);
+  void AppendStatement(android::StringPiece statement);
 
   // Not quite the same as a name, but good enough.
   const std::string& GetName() const override {
@@ -239,11 +240,12 @@
 
 class ClassDefinition : public ClassMember {
  public:
-  static void WriteJavaFile(const ClassDefinition* def, const android::StringPiece& package,
-                            bool final, bool strip_api_annotations, io::OutputStream* out);
+  static void WriteJavaFile(const ClassDefinition* def, android::StringPiece package, bool final,
+                            bool strip_api_annotations, io::OutputStream* out);
 
-  ClassDefinition(const android::StringPiece& name, ClassQualifier qualifier, bool createIfEmpty)
-      : name_(name.to_string()), qualifier_(qualifier), create_if_empty_(createIfEmpty) {}
+  ClassDefinition(android::StringPiece name, ClassQualifier qualifier, bool createIfEmpty)
+      : name_(name), qualifier_(qualifier), create_if_empty_(createIfEmpty) {
+  }
 
   enum class Result {
     kAdded,
diff --git a/tools/aapt2/java/JavaClassGenerator.cpp b/tools/aapt2/java/JavaClassGenerator.cpp
index a25ca22..7665d0e 100644
--- a/tools/aapt2/java/JavaClassGenerator.cpp
+++ b/tools/aapt2/java/JavaClassGenerator.cpp
@@ -57,14 +57,14 @@
     "transient",  "try",          "void",      "volatile",   "while",
     "true",       "false",        "null"};
 
-static bool IsValidSymbol(const StringPiece& symbol) {
+static bool IsValidSymbol(StringPiece symbol) {
   return sJavaIdentifiers.find(symbol) == sJavaIdentifiers.end();
 }
 
 // Java symbols can not contain . or -, but those are valid in a resource name.
 // Replace those with '_'.
-std::string JavaClassGenerator::TransformToFieldName(const StringPiece& symbol) {
-  std::string output = symbol.to_string();
+std::string JavaClassGenerator::TransformToFieldName(StringPiece symbol) {
+  std::string output(symbol);
   for (char& c : output) {
     if (c == '.' || c == '-') {
       c = '_';
@@ -84,7 +84,7 @@
 // Foo_bar
 static std::string TransformNestedAttr(const ResourceNameRef& attr_name,
                                        const std::string& styleable_class_name,
-                                       const StringPiece& package_name_to_generate) {
+                                       StringPiece package_name_to_generate) {
   std::string output = styleable_class_name;
 
   // We may reference IDs from other packages, so prefix the entry name with
@@ -226,16 +226,15 @@
 
 static FieldReference GetRFieldReference(const ResourceName& name,
                                          StringPiece fallback_package_name) {
-  const std::string package_name =
-      name.package.empty() ? fallback_package_name.to_string() : name.package;
+  const std::string_view package_name = name.package.empty() ? fallback_package_name : name.package;
   const std::string entry = JavaClassGenerator::TransformToFieldName(name.entry);
-  return FieldReference(StringPrintf("%s.R.%s.%s", package_name.c_str(),
-                                     name.type.to_string().data(), entry.c_str()));
+  return FieldReference(
+      StringPrintf("%s.R.%s.%s", package_name.data(), name.type.to_string().data(), entry.c_str()));
 }
 
 bool JavaClassGenerator::ProcessStyleable(const ResourceNameRef& name, const ResourceId& id,
                                           const Styleable& styleable,
-                                          const StringPiece& package_name_to_generate,
+                                          StringPiece package_name_to_generate,
                                           ClassDefinition* out_class_def,
                                           MethodDefinition* out_rewrite_method,
                                           Printer* r_txt_printer) {
@@ -314,7 +313,8 @@
         return true;
       }
       const StringPiece attr_comment_line = entry.symbol.value().attribute->GetComment();
-      return attr_comment_line.contains("@removed") || attr_comment_line.contains("@hide");
+      return attr_comment_line.find("@removed") != std::string::npos ||
+             attr_comment_line.find("@hide") != std::string::npos;
     });
     documentation_attrs.erase(documentation_remove_iter, documentation_attrs.end());
 
@@ -397,7 +397,7 @@
         comment = styleable_attr.symbol.value().attribute->GetComment();
       }
 
-      if (comment.contains("@removed")) {
+      if (comment.find("@removed") != std::string::npos) {
         // Removed attributes are public but hidden from the documentation, so
         // don't emit them as part of the class documentation.
         continue;
@@ -497,7 +497,7 @@
   }
 
   if (out_rewrite_method != nullptr) {
-    const std::string type_str = name.type.to_string();
+    const auto type_str = name.type.to_string();
     out_rewrite_method->AppendStatement(
         StringPrintf("%s.%s = (%s.%s & 0x00ffffff) | packageIdBits;", type_str.data(),
                      field_name.data(), type_str.data(), field_name.data()));
@@ -505,8 +505,7 @@
 }
 
 std::optional<std::string> JavaClassGenerator::UnmangleResource(
-    const StringPiece& package_name, const StringPiece& package_name_to_generate,
-    const ResourceEntry& entry) {
+    StringPiece package_name, StringPiece package_name_to_generate, const ResourceEntry& entry) {
   if (SkipSymbol(entry.visibility.level)) {
     return {};
   }
@@ -528,7 +527,7 @@
   return {std::move(unmangled_name)};
 }
 
-bool JavaClassGenerator::ProcessType(const StringPiece& package_name_to_generate,
+bool JavaClassGenerator::ProcessType(StringPiece package_name_to_generate,
                                      const ResourceTablePackage& package,
                                      const ResourceTableType& type,
                                      ClassDefinition* out_type_class_def,
@@ -577,7 +576,7 @@
   return true;
 }
 
-bool JavaClassGenerator::Generate(const StringPiece& package_name_to_generate, OutputStream* out,
+bool JavaClassGenerator::Generate(StringPiece package_name_to_generate, OutputStream* out,
                                   OutputStream* out_r_txt) {
   return Generate(package_name_to_generate, package_name_to_generate, out, out_r_txt);
 }
@@ -591,8 +590,8 @@
   }
 }
 
-bool JavaClassGenerator::Generate(const StringPiece& package_name_to_generate,
-                                  const StringPiece& out_package_name, OutputStream* out,
+bool JavaClassGenerator::Generate(StringPiece package_name_to_generate,
+                                  StringPiece out_package_name, OutputStream* out,
                                   OutputStream* out_r_txt) {
   ClassDefinition r_class("R", ClassQualifier::kNone, true);
   std::unique_ptr<MethodDefinition> rewrite_method;
diff --git a/tools/aapt2/java/JavaClassGenerator.h b/tools/aapt2/java/JavaClassGenerator.h
index b45a2f1..234df04 100644
--- a/tools/aapt2/java/JavaClassGenerator.h
+++ b/tools/aapt2/java/JavaClassGenerator.h
@@ -70,16 +70,16 @@
   // All symbols technically belong to a single package, but linked libraries will
   // have their names mangled, denoting that they came from a different package.
   // We need to generate these symbols in a separate file. Returns true on success.
-  bool Generate(const android::StringPiece& package_name_to_generate, io::OutputStream* out,
+  bool Generate(android::StringPiece package_name_to_generate, io::OutputStream* out,
                 io::OutputStream* out_r_txt = nullptr);
 
-  bool Generate(const android::StringPiece& package_name_to_generate,
-                const android::StringPiece& output_package_name, io::OutputStream* out,
+  bool Generate(android::StringPiece package_name_to_generate,
+                android::StringPiece output_package_name, io::OutputStream* out,
                 io::OutputStream* out_r_txt = nullptr);
 
   const std::string& GetError() const;
 
-  static std::string TransformToFieldName(const android::StringPiece& symbol);
+  static std::string TransformToFieldName(android::StringPiece symbol);
 
  private:
   bool SkipSymbol(Visibility::Level state);
@@ -87,11 +87,11 @@
 
   // Returns the unmangled resource entry name if the unmangled package is the same as
   // package_name_to_generate. Returns nothing if the resource should be skipped.
-  std::optional<std::string> UnmangleResource(const android::StringPiece& package_name,
-                                              const android::StringPiece& package_name_to_generate,
+  std::optional<std::string> UnmangleResource(android::StringPiece package_name,
+                                              android::StringPiece package_name_to_generate,
                                               const ResourceEntry& entry);
 
-  bool ProcessType(const android::StringPiece& package_name_to_generate,
+  bool ProcessType(android::StringPiece package_name_to_generate,
                    const ResourceTablePackage& package, const ResourceTableType& type,
                    ClassDefinition* out_type_class_def, MethodDefinition* out_rewrite_method_def,
                    text::Printer* r_txt_printer);
@@ -106,8 +106,7 @@
   // its package ID if `out_rewrite_method` is not nullptr.
   // `package_name_to_generate` is the package
   bool ProcessStyleable(const ResourceNameRef& name, const ResourceId& id,
-                        const Styleable& styleable,
-                        const android::StringPiece& package_name_to_generate,
+                        const Styleable& styleable, android::StringPiece package_name_to_generate,
                         ClassDefinition* out_class_def, MethodDefinition* out_rewrite_method,
                         text::Printer* r_txt_printer);
 
diff --git a/tools/aapt2/link/ManifestFixer.cpp b/tools/aapt2/link/ManifestFixer.cpp
index d0850b8..56d9075 100644
--- a/tools/aapt2/link/ManifestFixer.cpp
+++ b/tools/aapt2/link/ManifestFixer.cpp
@@ -646,8 +646,8 @@
   return true;
 }
 
-static void FullyQualifyClassName(const StringPiece& package, const StringPiece& attr_ns,
-                                  const StringPiece& attr_name, xml::Element* el) {
+static void FullyQualifyClassName(StringPiece package, StringPiece attr_ns, StringPiece attr_name,
+                                  xml::Element* el) {
   xml::Attribute* attr = el->FindAttribute(attr_ns, attr_name);
   if (attr != nullptr) {
     if (std::optional<std::string> new_value =
@@ -657,7 +657,7 @@
   }
 }
 
-static bool RenameManifestPackage(const StringPiece& package_override, xml::Element* manifest_el) {
+static bool RenameManifestPackage(StringPiece package_override, xml::Element* manifest_el) {
   xml::Attribute* attr = manifest_el->FindAttribute({}, "package");
 
   // We've already verified that the manifest element is present, with a package
@@ -665,7 +665,7 @@
   CHECK(attr != nullptr);
 
   std::string original_package = std::move(attr->value);
-  attr->value = package_override.to_string();
+  attr->value.assign(package_override);
 
   xml::Element* application_el = manifest_el->FindChild({}, "application");
   if (application_el != nullptr) {
diff --git a/tools/aapt2/link/ManifestFixer_test.cpp b/tools/aapt2/link/ManifestFixer_test.cpp
index 8d1a647..7180ae6 100644
--- a/tools/aapt2/link/ManifestFixer_test.cpp
+++ b/tools/aapt2/link/ManifestFixer_test.cpp
@@ -61,12 +61,12 @@
             .Build();
   }
 
-  std::unique_ptr<xml::XmlResource> Verify(const StringPiece& str) {
+  std::unique_ptr<xml::XmlResource> Verify(StringPiece str) {
     return VerifyWithOptions(str, {});
   }
 
-  std::unique_ptr<xml::XmlResource> VerifyWithOptions(
-      const StringPiece& str, const ManifestFixerOptions& options) {
+  std::unique_ptr<xml::XmlResource> VerifyWithOptions(StringPiece str,
+                                                      const ManifestFixerOptions& options) {
     std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(str);
     ManifestFixer fixer(options);
     if (fixer.Consume(mContext.get(), doc.get())) {
diff --git a/tools/aapt2/link/ReferenceLinker.cpp b/tools/aapt2/link/ReferenceLinker.cpp
index f2a93a8..9dadfb2 100644
--- a/tools/aapt2/link/ReferenceLinker.cpp
+++ b/tools/aapt2/link/ReferenceLinker.cpp
@@ -189,8 +189,7 @@
  public:
   EmptyDeclStack() = default;
 
-  std::optional<xml::ExtractedPackage> TransformPackageAlias(
-      const StringPiece& alias) const override {
+  std::optional<xml::ExtractedPackage> TransformPackageAlias(StringPiece alias) const override {
     if (alias.empty()) {
       return xml::ExtractedPackage{{}, true /*private*/};
     }
@@ -206,8 +205,7 @@
       : alias_namespaces_(std::move(namespaces)) {
   }
 
-  std::optional<xml::ExtractedPackage> TransformPackageAlias(
-      const StringPiece& alias) const override {
+  std::optional<xml::ExtractedPackage> TransformPackageAlias(StringPiece alias) const override {
     if (alias.empty()) {
       return xml::ExtractedPackage{{}, true /*private*/};
     }
diff --git a/tools/aapt2/link/TableMerger.cpp b/tools/aapt2/link/TableMerger.cpp
index c9f0964..67a4828 100644
--- a/tools/aapt2/link/TableMerger.cpp
+++ b/tools/aapt2/link/TableMerger.cpp
@@ -66,7 +66,7 @@
 
 // This will merge and mangle resources from a static library. It is assumed that all FileReferences
 // have correctly set their io::IFile*.
-bool TableMerger::MergeAndMangle(const android::Source& src, const StringPiece& package_name,
+bool TableMerger::MergeAndMangle(const android::Source& src, StringPiece package_name,
                                  ResourceTable* table) {
   bool error = false;
   for (auto& package : table->packages) {
@@ -326,8 +326,8 @@
     const std::string& package, const FileReference& file_ref) {
   StringPiece prefix, entry, suffix;
   if (util::ExtractResFilePathParts(*file_ref.path, &prefix, &entry, &suffix)) {
-    std::string mangled_entry = NameMangler::MangleEntry(package, entry.to_string());
-    std::string newPath = prefix.to_string() + mangled_entry + suffix.to_string();
+    std::string mangled_entry = NameMangler::MangleEntry(package, entry);
+    std::string newPath = (std::string(prefix) += mangled_entry) += suffix;
     std::unique_ptr<FileReference> new_file_ref =
         util::make_unique<FileReference>(main_table_->string_pool.MakeRef(newPath));
     new_file_ref->SetComment(file_ref.GetComment());
diff --git a/tools/aapt2/link/TableMerger.h b/tools/aapt2/link/TableMerger.h
index 2ba2123..37daf42 100644
--- a/tools/aapt2/link/TableMerger.h
+++ b/tools/aapt2/link/TableMerger.h
@@ -61,7 +61,7 @@
   // References are made to this ResourceTable for efficiency reasons.
   TableMerger(IAaptContext* context, ResourceTable* out_table, const TableMergerOptions& options);
 
-  inline const std::set<std::string>& merged_packages() const {
+  inline const std::set<std::string, std::less<>>& merged_packages() const {
     return merged_packages_;
   }
 
@@ -71,7 +71,7 @@
 
   // Merges resources from the given package, mangling the name. This is for static libraries.
   // All FileReference values must have their io::IFile set.
-  bool MergeAndMangle(const android::Source& src, const android::StringPiece& package,
+  bool MergeAndMangle(const android::Source& src, android::StringPiece package,
                       ResourceTable* table);
 
   // Merges a compiled file that belongs to this same or empty package.
@@ -84,7 +84,7 @@
   ResourceTable* main_table_;
   TableMergerOptions options_;
   ResourceTablePackage* main_package_;
-  std::set<std::string> merged_packages_;
+  std::set<std::string, std::less<>> merged_packages_;
 
   bool MergeImpl(const android::Source& src, ResourceTable* src_table, bool overlay,
                  bool allow_new);
diff --git a/tools/aapt2/optimize/MultiApkGenerator.cpp b/tools/aapt2/optimize/MultiApkGenerator.cpp
index f994e27..f01db3d 100644
--- a/tools/aapt2/optimize/MultiApkGenerator.cpp
+++ b/tools/aapt2/optimize/MultiApkGenerator.cpp
@@ -113,12 +113,12 @@
 };
 
 class SignatureFilter : public IPathFilter {
-  bool Keep(const std::string& path) override {
+  bool Keep(std::string_view path) override {
     static std::regex signature_regex(R"regex(^META-INF/.*\.(RSA|DSA|EC|SF)$)regex");
-    if (std::regex_search(path, signature_regex)) {
+    if (std::regex_search(path.begin(), path.end(), signature_regex)) {
       return false;
     }
-    return !(path == "META-INF/MANIFEST.MF");
+    return path != "META-INF/MANIFEST.MF";
   }
 };
 
diff --git a/tools/aapt2/optimize/Obfuscator.cpp b/tools/aapt2/optimize/Obfuscator.cpp
index f704f26..1fdd728 100644
--- a/tools/aapt2/optimize/Obfuscator.cpp
+++ b/tools/aapt2/optimize/Obfuscator.cpp
@@ -35,7 +35,7 @@
 Obfuscator::Obfuscator(std::map<std::string, std::string>& path_map_out) : path_map_(path_map_out) {
 }
 
-std::string ShortenFileName(const android::StringPiece& file_path, int output_length) {
+std::string ShortenFileName(android::StringPiece file_path, int output_length) {
   std::size_t hash_num = std::hash<android::StringPiece>{}(file_path);
   std::string result = "";
   // Convert to (modified) base64 so that it is a proper file path.
@@ -58,9 +58,9 @@
   }
 }
 
-std::string GetShortenedPath(const android::StringPiece& shortened_filename,
-                             const android::StringPiece& extension, int collision_count) {
-  std::string shortened_path = "res/" + shortened_filename.to_string();
+std::string GetShortenedPath(android::StringPiece shortened_filename,
+                             android::StringPiece extension, int collision_count) {
+  std::string shortened_path = std::string("res/") += shortened_filename;
   if (collision_count > 0) {
     shortened_path += std::to_string(collision_count);
   }
diff --git a/tools/aapt2/optimize/VersionCollapser_test.cpp b/tools/aapt2/optimize/VersionCollapser_test.cpp
index aa0d0c0..18dcd6b 100644
--- a/tools/aapt2/optimize/VersionCollapser_test.cpp
+++ b/tools/aapt2/optimize/VersionCollapser_test.cpp
@@ -23,7 +23,7 @@
 namespace aapt {
 
 static std::unique_ptr<ResourceTable> BuildTableWithConfigs(
-    const StringPiece& name, std::initializer_list<std::string> list) {
+    StringPiece name, std::initializer_list<std::string> list) {
   test::ResourceTableBuilder builder;
   for (const std::string& item : list) {
     builder.AddSimple(name, test::ParseConfigOrDie(item));
diff --git a/tools/aapt2/process/SymbolTable.cpp b/tools/aapt2/process/SymbolTable.cpp
index 92b45c3..bca62da 100644
--- a/tools/aapt2/process/SymbolTable.cpp
+++ b/tools/aapt2/process/SymbolTable.cpp
@@ -218,7 +218,7 @@
   return symbol;
 }
 
-bool AssetManagerSymbolSource::AddAssetPath(const StringPiece& path) {
+bool AssetManagerSymbolSource::AddAssetPath(StringPiece path) {
   TRACE_CALL();
   if (std::unique_ptr<const ApkAssets> apk = ApkAssets::Load(path.data())) {
     apk_assets_.push_back(std::move(apk));
diff --git a/tools/aapt2/process/SymbolTable.h b/tools/aapt2/process/SymbolTable.h
index c17837c..b09ff70 100644
--- a/tools/aapt2/process/SymbolTable.h
+++ b/tools/aapt2/process/SymbolTable.h
@@ -192,7 +192,7 @@
  public:
   AssetManagerSymbolSource() = default;
 
-  bool AddAssetPath(const android::StringPiece& path);
+  bool AddAssetPath(android::StringPiece path);
   std::map<size_t, std::string> GetAssignedPackageIds() const;
   bool IsPackageDynamic(uint32_t packageId, const std::string& package_name) const;
 
diff --git a/tools/aapt2/test/Builders.cpp b/tools/aapt2/test/Builders.cpp
index 30336e2..65f63dc 100644
--- a/tools/aapt2/test/Builders.cpp
+++ b/tools/aapt2/test/Builders.cpp
@@ -34,61 +34,53 @@
 namespace aapt {
 namespace test {
 
-ResourceTableBuilder& ResourceTableBuilder::AddSimple(const StringPiece& name,
-                                                      const ResourceId& id) {
+ResourceTableBuilder& ResourceTableBuilder::AddSimple(StringPiece name, const ResourceId& id) {
   return AddValue(name, id, util::make_unique<Id>());
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddSimple(const StringPiece& name,
+ResourceTableBuilder& ResourceTableBuilder::AddSimple(StringPiece name,
                                                       const ConfigDescription& config,
                                                       const ResourceId& id) {
   return AddValue(name, config, id, util::make_unique<Id>());
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddReference(const StringPiece& name,
-                                                         const StringPiece& ref) {
+ResourceTableBuilder& ResourceTableBuilder::AddReference(StringPiece name, StringPiece ref) {
   return AddReference(name, {}, ref);
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddReference(const StringPiece& name,
-                                                         const ResourceId& id,
-                                                         const StringPiece& ref) {
+ResourceTableBuilder& ResourceTableBuilder::AddReference(StringPiece name, const ResourceId& id,
+                                                         StringPiece ref) {
   return AddValue(name, id, util::make_unique<Reference>(ParseNameOrDie(ref)));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddString(const StringPiece& name,
-                                                      const StringPiece& str) {
+ResourceTableBuilder& ResourceTableBuilder::AddString(StringPiece name, StringPiece str) {
   return AddString(name, {}, str);
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddString(const StringPiece& name, const ResourceId& id,
-                                                      const StringPiece& str) {
+ResourceTableBuilder& ResourceTableBuilder::AddString(StringPiece name, const ResourceId& id,
+                                                      StringPiece str) {
   return AddValue(name, id, util::make_unique<String>(table_->string_pool.MakeRef(str)));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddString(const StringPiece& name, const ResourceId& id,
+ResourceTableBuilder& ResourceTableBuilder::AddString(StringPiece name, const ResourceId& id,
                                                       const ConfigDescription& config,
-                                                      const StringPiece& str) {
+                                                      StringPiece str) {
   return AddValue(name, config, id, util::make_unique<String>(table_->string_pool.MakeRef(str)));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddFileReference(const StringPiece& name,
-                                                             const StringPiece& path,
+ResourceTableBuilder& ResourceTableBuilder::AddFileReference(StringPiece name, StringPiece path,
                                                              io::IFile* file) {
   return AddFileReference(name, {}, path, file);
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddFileReference(const StringPiece& name,
-                                                             const ResourceId& id,
-                                                             const StringPiece& path,
-                                                             io::IFile* file) {
+ResourceTableBuilder& ResourceTableBuilder::AddFileReference(StringPiece name, const ResourceId& id,
+                                                             StringPiece path, io::IFile* file) {
   auto file_ref = util::make_unique<FileReference>(table_->string_pool.MakeRef(path));
   file_ref->file = file;
   return AddValue(name, id, std::move(file_ref));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddFileReference(const StringPiece& name,
-                                                             const StringPiece& path,
+ResourceTableBuilder& ResourceTableBuilder::AddFileReference(StringPiece name, StringPiece path,
                                                              const ConfigDescription& config,
                                                              io::IFile* file) {
   auto file_ref = util::make_unique<FileReference>(table_->string_pool.MakeRef(path));
@@ -96,17 +88,17 @@
   return AddValue(name, config, {}, std::move(file_ref));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddValue(const StringPiece& name,
+ResourceTableBuilder& ResourceTableBuilder::AddValue(StringPiece name,
                                                      std::unique_ptr<Value> value) {
   return AddValue(name, {}, std::move(value));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddValue(const StringPiece& name, const ResourceId& id,
+ResourceTableBuilder& ResourceTableBuilder::AddValue(StringPiece name, const ResourceId& id,
                                                      std::unique_ptr<Value> value) {
   return AddValue(name, {}, id, std::move(value));
 }
 
-ResourceTableBuilder& ResourceTableBuilder::AddValue(const StringPiece& name,
+ResourceTableBuilder& ResourceTableBuilder::AddValue(StringPiece name,
                                                      const ConfigDescription& config,
                                                      const ResourceId& id,
                                                      std::unique_ptr<Value> value) {
@@ -121,8 +113,7 @@
   return *this;
 }
 
-ResourceTableBuilder& ResourceTableBuilder::SetSymbolState(const StringPiece& name,
-                                                           const ResourceId& id,
+ResourceTableBuilder& ResourceTableBuilder::SetSymbolState(StringPiece name, const ResourceId& id,
                                                            Visibility::Level level,
                                                            bool allow_new) {
   ResourceName res_name = ParseNameOrDie(name);
@@ -136,9 +127,8 @@
   return *this;
 }
 
-ResourceTableBuilder& ResourceTableBuilder::SetOverlayable(const StringPiece& name,
+ResourceTableBuilder& ResourceTableBuilder::SetOverlayable(StringPiece name,
                                                            const OverlayableItem& overlayable) {
-
   ResourceName res_name = ParseNameOrDie(name);
   CHECK(table_->AddResource(
       NewResourceBuilder(res_name).SetOverlayable(overlayable).SetAllowMangled(true).Build(),
@@ -159,8 +149,7 @@
   return std::move(table_);
 }
 
-std::unique_ptr<Reference> BuildReference(const StringPiece& ref,
-                                          const std::optional<ResourceId>& id) {
+std::unique_ptr<Reference> BuildReference(StringPiece ref, const std::optional<ResourceId>& id) {
   std::unique_ptr<Reference> reference = util::make_unique<Reference>(ParseNameOrDie(ref));
   reference->id = id;
   return reference;
@@ -188,7 +177,7 @@
   return *this;
 }
 
-AttributeBuilder& AttributeBuilder::AddItem(const StringPiece& name, uint32_t value) {
+AttributeBuilder& AttributeBuilder::AddItem(StringPiece name, uint32_t value) {
   attr_->symbols.push_back(
       Attribute::Symbol{Reference(ResourceName({}, ResourceType::kId, name)), value});
   return *this;
@@ -198,17 +187,17 @@
   return std::move(attr_);
 }
 
-StyleBuilder& StyleBuilder::SetParent(const StringPiece& str) {
+StyleBuilder& StyleBuilder::SetParent(StringPiece str) {
   style_->parent = Reference(ParseNameOrDie(str));
   return *this;
 }
 
-StyleBuilder& StyleBuilder::AddItem(const StringPiece& str, std::unique_ptr<Item> value) {
+StyleBuilder& StyleBuilder::AddItem(StringPiece str, std::unique_ptr<Item> value) {
   style_->entries.push_back(Style::Entry{Reference(ParseNameOrDie(str)), std::move(value)});
   return *this;
 }
 
-StyleBuilder& StyleBuilder::AddItem(const StringPiece& str, const ResourceId& id,
+StyleBuilder& StyleBuilder::AddItem(StringPiece str, const ResourceId& id,
                                     std::unique_ptr<Item> value) {
   AddItem(str, std::move(value));
   style_->entries.back().key.id = id;
@@ -219,8 +208,7 @@
   return std::move(style_);
 }
 
-StyleableBuilder& StyleableBuilder::AddItem(const StringPiece& str,
-                                            const std::optional<ResourceId>& id) {
+StyleableBuilder& StyleableBuilder::AddItem(StringPiece str, const std::optional<ResourceId>& id) {
   styleable_->entries.push_back(Reference(ParseNameOrDie(str)));
   styleable_->entries.back().id = id;
   return *this;
@@ -230,7 +218,7 @@
   return std::move(styleable_);
 }
 
-std::unique_ptr<xml::XmlResource> BuildXmlDom(const StringPiece& str) {
+std::unique_ptr<xml::XmlResource> BuildXmlDom(StringPiece str) {
   std::string input = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
   input.append(str.data(), str.size());
   StringInputStream in(input);
@@ -241,7 +229,7 @@
 }
 
 std::unique_ptr<xml::XmlResource> BuildXmlDomForPackageName(IAaptContext* context,
-                                                            const StringPiece& str) {
+                                                            StringPiece str) {
   std::unique_ptr<xml::XmlResource> doc = BuildXmlDom(str);
   doc->file.name.package = context->GetCompilationPackage();
   return doc;
diff --git a/tools/aapt2/test/Builders.h b/tools/aapt2/test/Builders.h
index 780bd0d..f03d6fc 100644
--- a/tools/aapt2/test/Builders.h
+++ b/tools/aapt2/test/Builders.h
@@ -38,40 +38,35 @@
  public:
   ResourceTableBuilder() = default;
 
-  ResourceTableBuilder& AddSimple(const android::StringPiece& name, const ResourceId& id = {});
-  ResourceTableBuilder& AddSimple(const android::StringPiece& name,
+  ResourceTableBuilder& AddSimple(android::StringPiece name, const ResourceId& id = {});
+  ResourceTableBuilder& AddSimple(android::StringPiece name,
                                   const android::ConfigDescription& config,
                                   const ResourceId& id = {});
-  ResourceTableBuilder& AddReference(const android::StringPiece& name,
-                                     const android::StringPiece& ref);
-  ResourceTableBuilder& AddReference(const android::StringPiece& name, const ResourceId& id,
-                                     const android::StringPiece& ref);
-  ResourceTableBuilder& AddString(const android::StringPiece& name,
-                                  const android::StringPiece& str);
-  ResourceTableBuilder& AddString(const android::StringPiece& name, const ResourceId& id,
-                                  const android::StringPiece& str);
-  ResourceTableBuilder& AddString(const android::StringPiece& name, const ResourceId& id,
+  ResourceTableBuilder& AddReference(android::StringPiece name, android::StringPiece ref);
+  ResourceTableBuilder& AddReference(android::StringPiece name, const ResourceId& id,
+                                     android::StringPiece ref);
+  ResourceTableBuilder& AddString(android::StringPiece name, android::StringPiece str);
+  ResourceTableBuilder& AddString(android::StringPiece name, const ResourceId& id,
+                                  android::StringPiece str);
+  ResourceTableBuilder& AddString(android::StringPiece name, const ResourceId& id,
                                   const android::ConfigDescription& config,
-                                  const android::StringPiece& str);
-  ResourceTableBuilder& AddFileReference(const android::StringPiece& name,
-                                         const android::StringPiece& path,
+                                  android::StringPiece str);
+  ResourceTableBuilder& AddFileReference(android::StringPiece name, android::StringPiece path,
                                          io::IFile* file = nullptr);
-  ResourceTableBuilder& AddFileReference(const android::StringPiece& name, const ResourceId& id,
-                                         const android::StringPiece& path,
-                                         io::IFile* file = nullptr);
-  ResourceTableBuilder& AddFileReference(const android::StringPiece& name,
-                                         const android::StringPiece& path,
+  ResourceTableBuilder& AddFileReference(android::StringPiece name, const ResourceId& id,
+                                         android::StringPiece path, io::IFile* file = nullptr);
+  ResourceTableBuilder& AddFileReference(android::StringPiece name, android::StringPiece path,
                                          const android::ConfigDescription& config,
                                          io::IFile* file = nullptr);
-  ResourceTableBuilder& AddValue(const android::StringPiece& name, std::unique_ptr<Value> value);
-  ResourceTableBuilder& AddValue(const android::StringPiece& name, const ResourceId& id,
+  ResourceTableBuilder& AddValue(android::StringPiece name, std::unique_ptr<Value> value);
+  ResourceTableBuilder& AddValue(android::StringPiece name, const ResourceId& id,
                                  std::unique_ptr<Value> value);
-  ResourceTableBuilder& AddValue(const android::StringPiece& name,
-                                 const android::ConfigDescription& config,
-                                 const ResourceId& id, std::unique_ptr<Value> value);
-  ResourceTableBuilder& SetSymbolState(const android::StringPiece& name, const ResourceId& id,
+  ResourceTableBuilder& AddValue(android::StringPiece name,
+                                 const android::ConfigDescription& config, const ResourceId& id,
+                                 std::unique_ptr<Value> value);
+  ResourceTableBuilder& SetSymbolState(android::StringPiece name, const ResourceId& id,
                                        Visibility::Level level, bool allow_new = false);
-  ResourceTableBuilder& SetOverlayable(const android::StringPiece& name,
+  ResourceTableBuilder& SetOverlayable(android::StringPiece name,
                                        const OverlayableItem& overlayable);
   ResourceTableBuilder& Add(NewResource&& res);
 
@@ -84,7 +79,7 @@
   std::unique_ptr<ResourceTable> table_ = util::make_unique<ResourceTable>();
 };
 
-std::unique_ptr<Reference> BuildReference(const android::StringPiece& ref,
+std::unique_ptr<Reference> BuildReference(android::StringPiece ref,
                                           const std::optional<ResourceId>& id = {});
 std::unique_ptr<BinaryPrimitive> BuildPrimitive(uint8_t type, uint32_t data);
 
@@ -101,7 +96,7 @@
     return *this;
   }
 
-  ValueBuilder& SetComment(const android::StringPiece& str) {
+  ValueBuilder& SetComment(android::StringPiece str) {
     value_->SetComment(str);
     return *this;
   }
@@ -121,7 +116,7 @@
   AttributeBuilder();
   AttributeBuilder& SetTypeMask(uint32_t typeMask);
   AttributeBuilder& SetWeak(bool weak);
-  AttributeBuilder& AddItem(const android::StringPiece& name, uint32_t value);
+  AttributeBuilder& AddItem(android::StringPiece name, uint32_t value);
   std::unique_ptr<Attribute> Build();
 
  private:
@@ -133,9 +128,9 @@
 class StyleBuilder {
  public:
   StyleBuilder() = default;
-  StyleBuilder& SetParent(const android::StringPiece& str);
-  StyleBuilder& AddItem(const android::StringPiece& str, std::unique_ptr<Item> value);
-  StyleBuilder& AddItem(const android::StringPiece& str, const ResourceId& id,
+  StyleBuilder& SetParent(android::StringPiece str);
+  StyleBuilder& AddItem(android::StringPiece str, std::unique_ptr<Item> value);
+  StyleBuilder& AddItem(android::StringPiece str, const ResourceId& id,
                         std::unique_ptr<Item> value);
   std::unique_ptr<Style> Build();
 
@@ -148,8 +143,7 @@
 class StyleableBuilder {
  public:
   StyleableBuilder() = default;
-  StyleableBuilder& AddItem(const android::StringPiece& str,
-                            const std::optional<ResourceId>& id = {});
+  StyleableBuilder& AddItem(android::StringPiece str, const std::optional<ResourceId>& id = {});
   std::unique_ptr<Styleable> Build();
 
  private:
@@ -158,9 +152,9 @@
   std::unique_ptr<Styleable> styleable_ = util::make_unique<Styleable>();
 };
 
-std::unique_ptr<xml::XmlResource> BuildXmlDom(const android::StringPiece& str);
+std::unique_ptr<xml::XmlResource> BuildXmlDom(android::StringPiece str);
 std::unique_ptr<xml::XmlResource> BuildXmlDomForPackageName(IAaptContext* context,
-                                                            const android::StringPiece& str);
+                                                            android::StringPiece str);
 
 class ArtifactBuilder {
  public:
diff --git a/tools/aapt2/test/Common.cpp b/tools/aapt2/test/Common.cpp
index eca0c1c..cdf24534 100644
--- a/tools/aapt2/test/Common.cpp
+++ b/tools/aapt2/test/Common.cpp
@@ -44,10 +44,9 @@
 }
 
 template <>
-Value* GetValueForConfigAndProduct<Value>(ResourceTable* table,
-                                          const android::StringPiece& res_name,
+Value* GetValueForConfigAndProduct<Value>(ResourceTable* table, android::StringPiece res_name,
                                           const ConfigDescription& config,
-                                          const android::StringPiece& product) {
+                                          android::StringPiece product) {
   std::optional<ResourceTable::SearchResult> result = table->FindResource(ParseNameOrDie(res_name));
   if (result) {
     ResourceConfigValue* config_value = result.value().entry->FindValue(config, product);
diff --git a/tools/aapt2/test/Common.h b/tools/aapt2/test/Common.h
index 3f28361..83a0f3f 100644
--- a/tools/aapt2/test/Common.h
+++ b/tools/aapt2/test/Common.h
@@ -39,22 +39,22 @@
 
 android::IDiagnostics* GetDiagnostics();
 
-inline ResourceName ParseNameOrDie(const android::StringPiece& str) {
+inline ResourceName ParseNameOrDie(android::StringPiece str) {
   ResourceNameRef ref;
   CHECK(ResourceUtils::ParseResourceName(str, &ref)) << "invalid resource name: " << str;
   return ref.ToResourceName();
 }
 
-inline android::ConfigDescription ParseConfigOrDie(const android::StringPiece& str) {
-    android::ConfigDescription config;
+inline android::ConfigDescription ParseConfigOrDie(android::StringPiece str) {
+  android::ConfigDescription config;
   CHECK(android::ConfigDescription::Parse(str, &config)) << "invalid configuration: " << str;
   return config;
 }
 
 template <typename T = Value>
-T* GetValueForConfigAndProduct(ResourceTable* table, const android::StringPiece& res_name,
+T* GetValueForConfigAndProduct(ResourceTable* table, android::StringPiece res_name,
                                const android::ConfigDescription& config,
-                               const android::StringPiece& product) {
+                               android::StringPiece product) {
   std::optional<ResourceTable::SearchResult> result = table->FindResource(ParseNameOrDie(res_name));
   if (result) {
     ResourceConfigValue* config_value = result.value().entry->FindValue(config, product);
@@ -66,25 +66,25 @@
 }
 
 template <>
-Value* GetValueForConfigAndProduct<Value>(ResourceTable* table,
-                                          const android::StringPiece& res_name,
+Value* GetValueForConfigAndProduct<Value>(ResourceTable* table, android::StringPiece res_name,
                                           const android::ConfigDescription& config,
-                                          const android::StringPiece& product);
+                                          android::StringPiece product);
 
 template <typename T = Value>
-T* GetValueForConfig(ResourceTable* table, const android::StringPiece& res_name,
+T* GetValueForConfig(ResourceTable* table, android::StringPiece res_name,
                      const android::ConfigDescription& config) {
   return GetValueForConfigAndProduct<T>(table, res_name, config, {});
 }
 
 template <typename T = Value>
-T* GetValue(ResourceTable* table, const android::StringPiece& res_name) {
+T* GetValue(ResourceTable* table, android::StringPiece res_name) {
   return GetValueForConfig<T>(table, res_name, {});
 }
 
 class TestFile : public io::IFile {
  public:
-  explicit TestFile(const android::StringPiece& path) : source_(path) {}
+  explicit TestFile(android::StringPiece path) : source_(path) {
+  }
 
   std::unique_ptr<io::IData> OpenAsData() override {
     return {};
diff --git a/tools/aapt2/test/Context.h b/tools/aapt2/test/Context.h
index 4e4973e..c5331fb 100644
--- a/tools/aapt2/test/Context.h
+++ b/tools/aapt2/test/Context.h
@@ -52,8 +52,8 @@
     return compilation_package_.value();
   }
 
-  void SetCompilationPackage(const android::StringPiece& package) {
-    compilation_package_ = package.to_string();
+  void SetCompilationPackage(android::StringPiece package) {
+    compilation_package_ = std::string(package);
   }
 
   uint8_t GetPackageId() override {
@@ -111,8 +111,8 @@
     return *this;
   }
 
-  ContextBuilder& SetCompilationPackage(const android::StringPiece& package) {
-    context_->compilation_package_ = package.to_string();
+  ContextBuilder& SetCompilationPackage(android::StringPiece package) {
+    context_->compilation_package_ = std::string(package);
     return *this;
   }
 
@@ -149,7 +149,7 @@
 
 class StaticSymbolSourceBuilder {
  public:
-  StaticSymbolSourceBuilder& AddPublicSymbol(const android::StringPiece& name, ResourceId id,
+  StaticSymbolSourceBuilder& AddPublicSymbol(android::StringPiece name, ResourceId id,
                                              std::unique_ptr<Attribute> attr = {}) {
     std::unique_ptr<SymbolTable::Symbol> symbol =
         util::make_unique<SymbolTable::Symbol>(id, std::move(attr), true);
@@ -159,7 +159,7 @@
     return *this;
   }
 
-  StaticSymbolSourceBuilder& AddSymbol(const android::StringPiece& name, ResourceId id,
+  StaticSymbolSourceBuilder& AddSymbol(android::StringPiece name, ResourceId id,
                                        std::unique_ptr<Attribute> attr = {}) {
     std::unique_ptr<SymbolTable::Symbol> symbol =
         util::make_unique<SymbolTable::Symbol>(id, std::move(attr), false);
diff --git a/tools/aapt2/test/Fixture.cpp b/tools/aapt2/test/Fixture.cpp
index dbc0e36..428372f 100644
--- a/tools/aapt2/test/Fixture.cpp
+++ b/tools/aapt2/test/Fixture.cpp
@@ -38,8 +38,8 @@
 
 const char* CommandTestFixture::kDefaultPackageName = "com.aapt.command.test";
 
-void ClearDirectory(const android::StringPiece& path) {
-  const std::string root_dir = path.to_string();
+void ClearDirectory(android::StringPiece path) {
+  const std::string root_dir(path);
   std::unique_ptr<DIR, decltype(closedir)*> dir(opendir(root_dir.data()), closedir);
   if (!dir) {
     StdErrDiagnostics().Error(android::DiagMessage()
@@ -91,8 +91,7 @@
 }
 
 bool CommandTestFixture::CompileFile(const std::string& path, const std::string& contents,
-                                     const android::StringPiece& out_dir,
-                                     android::IDiagnostics* diag) {
+                                     android::StringPiece out_dir, android::IDiagnostics* diag) {
   WriteFile(path, contents);
   CHECK(file::mkdirs(out_dir.data()));
   return CompileCommand(diag).Execute({path, "-o", out_dir, "-v"}, &std::cerr) == 0;
@@ -113,8 +112,8 @@
   return LinkCommand(diag).Execute(link_args, &std::cerr) == 0;
 }
 
-bool CommandTestFixture::Link(const std::vector<std::string>& args,
-                              const android::StringPiece& flat_dir, android::IDiagnostics* diag) {
+bool CommandTestFixture::Link(const std::vector<std::string>& args, android::StringPiece flat_dir,
+                              android::IDiagnostics* diag) {
   std::vector<android::StringPiece> link_args;
   for(const std::string& arg : args) {
     link_args.emplace_back(arg);
@@ -148,7 +147,7 @@
 }
 
 std::unique_ptr<io::IData> CommandTestFixture::OpenFileAsData(LoadedApk* apk,
-                                                              const android::StringPiece& path) {
+                                                              android::StringPiece path) {
   return apk
       ->GetFileCollection()
       ->FindFile(path)
diff --git a/tools/aapt2/test/Fixture.h b/tools/aapt2/test/Fixture.h
index 61403b7..ba4a734 100644
--- a/tools/aapt2/test/Fixture.h
+++ b/tools/aapt2/test/Fixture.h
@@ -48,7 +48,7 @@
   // Retrieves the absolute path of the specified relative path in the test directory. Directories
   // should be separated using forward slashes ('/'), and these slashes will be translated to
   // backslashes when running Windows tests.
-  std::string GetTestPath(const android::StringPiece& path) {
+  std::string GetTestPath(android::StringPiece path) {
     std::string base = temp_dir_;
     for (android::StringPiece part : util::Split(path, '/')) {
       file::AppendPath(&base, part);
@@ -73,22 +73,21 @@
   // Wries the contents of the file to the specified path. The file is compiled and the flattened
   // file is written to the out directory.
   bool CompileFile(const std::string& path, const std::string& contents,
-                   const android::StringPiece& flat_out_dir, android::IDiagnostics* diag);
+                   android::StringPiece flat_out_dir, android::IDiagnostics* diag);
 
   // Executes the link command with the specified arguments.
   bool Link(const std::vector<std::string>& args, android::IDiagnostics* diag);
 
   // Executes the link command with the specified arguments. The flattened files residing in the
   // flat directory will be added to the link command as file arguments.
-  bool Link(const std::vector<std::string>& args, const android::StringPiece& flat_dir,
+  bool Link(const std::vector<std::string>& args, android::StringPiece flat_dir,
             android::IDiagnostics* diag);
 
   // Creates a minimal android manifest within the test directory and returns the file path.
   std::string GetDefaultManifest(const char* package_name = kDefaultPackageName);
 
   // Returns pointer to data inside APK files
-  std::unique_ptr<io::IData> OpenFileAsData(LoadedApk* apk,
-                                            const android::StringPiece& path);
+  std::unique_ptr<io::IData> OpenFileAsData(LoadedApk* apk, android::StringPiece path);
 
   // Asserts that loading the tree from the specified file in the apk succeeds.
   void AssertLoadXml(LoadedApk* apk, const io::IData* data,
diff --git a/tools/aapt2/text/Printer.cpp b/tools/aapt2/text/Printer.cpp
index 243800c..8e491ac 100644
--- a/tools/aapt2/text/Printer.cpp
+++ b/tools/aapt2/text/Printer.cpp
@@ -26,7 +26,7 @@
 namespace aapt {
 namespace text {
 
-Printer& Printer::Println(const StringPiece& str) {
+Printer& Printer::Println(StringPiece str) {
   Print(str);
   return Print("\n");
 }
@@ -35,7 +35,7 @@
   return Print("\n");
 }
 
-Printer& Printer::Print(const StringPiece& str) {
+Printer& Printer::Print(StringPiece str) {
   if (error_) {
     return *this;
   }
@@ -47,7 +47,7 @@
     const auto new_line_iter = std::find(remaining_str_begin, remaining_str_end, '\n');
 
     // We will copy the string up until the next new-line (or end of string).
-    const StringPiece str_to_copy = str.substr(remaining_str_begin, new_line_iter);
+    const StringPiece str_to_copy(remaining_str_begin, new_line_iter - remaining_str_begin);
     if (!str_to_copy.empty()) {
       if (needs_indent_) {
         for (int i = 0; i < indent_level_; i++) {
diff --git a/tools/aapt2/text/Printer.h b/tools/aapt2/text/Printer.h
index f399f8e..f7ad98b 100644
--- a/tools/aapt2/text/Printer.h
+++ b/tools/aapt2/text/Printer.h
@@ -31,8 +31,8 @@
   explicit Printer(::aapt::io::OutputStream* out) : out_(out) {
   }
 
-  Printer& Print(const ::android::StringPiece& str);
-  Printer& Println(const ::android::StringPiece& str);
+  Printer& Print(android::StringPiece str);
+  Printer& Println(android::StringPiece str);
   Printer& Println();
 
   void Indent();
diff --git a/tools/aapt2/text/Unicode.cpp b/tools/aapt2/text/Unicode.cpp
index 3735b3e..5e25be3 100644
--- a/tools/aapt2/text/Unicode.cpp
+++ b/tools/aapt2/text/Unicode.cpp
@@ -77,7 +77,7 @@
          (codepoint == 0x3000);
 }
 
-bool IsJavaIdentifier(const StringPiece& str) {
+bool IsJavaIdentifier(StringPiece str) {
   Utf8Iterator iter(str);
 
   // Check the first character.
@@ -99,7 +99,7 @@
   return true;
 }
 
-bool IsValidResourceEntryName(const StringPiece& str) {
+bool IsValidResourceEntryName(StringPiece str) {
   Utf8Iterator iter(str);
 
   // Check the first character.
diff --git a/tools/aapt2/text/Unicode.h b/tools/aapt2/text/Unicode.h
index 546714e..ab3e82b 100644
--- a/tools/aapt2/text/Unicode.h
+++ b/tools/aapt2/text/Unicode.h
@@ -46,11 +46,11 @@
 
 // Returns true if the UTF8 string can be used as a Java identifier.
 // NOTE: This does not check against the set of reserved Java keywords.
-bool IsJavaIdentifier(const android::StringPiece& str);
+bool IsJavaIdentifier(android::StringPiece str);
 
 // Returns true if the UTF8 string can be used as the entry name of a resource name.
 // This is the `entry` part of package:type/entry.
-bool IsValidResourceEntryName(const android::StringPiece& str);
+bool IsValidResourceEntryName(android::StringPiece str);
 
 }  // namespace text
 }  // namespace aapt
diff --git a/tools/aapt2/text/Utf8Iterator.cpp b/tools/aapt2/text/Utf8Iterator.cpp
index 20b9073..0bd8a37 100644
--- a/tools/aapt2/text/Utf8Iterator.cpp
+++ b/tools/aapt2/text/Utf8Iterator.cpp
@@ -24,7 +24,7 @@
 namespace aapt {
 namespace text {
 
-Utf8Iterator::Utf8Iterator(const StringPiece& str)
+Utf8Iterator::Utf8Iterator(StringPiece str)
     : str_(str), current_pos_(0), next_pos_(0), current_codepoint_(0) {
   DoNext();
 }
diff --git a/tools/aapt2/text/Utf8Iterator.h b/tools/aapt2/text/Utf8Iterator.h
index 9318401..2bba198 100644
--- a/tools/aapt2/text/Utf8Iterator.h
+++ b/tools/aapt2/text/Utf8Iterator.h
@@ -25,7 +25,7 @@
 
 class Utf8Iterator {
  public:
-  explicit Utf8Iterator(const android::StringPiece& str);
+  explicit Utf8Iterator(android::StringPiece str);
 
   bool HasNext() const;
 
diff --git a/tools/aapt2/trace/TraceBuffer.cpp b/tools/aapt2/trace/TraceBuffer.cpp
index b4b31d9..da53739 100644
--- a/tools/aapt2/trace/TraceBuffer.cpp
+++ b/tools/aapt2/trace/TraceBuffer.cpp
@@ -103,7 +103,7 @@
   s << tag;
   s << " ";
   for (auto& arg : args) {
-    s << arg.to_string();
+    s << arg;
     s << " ";
   }
   tracebuffer::Add(s.str(), tracebuffer::kBegin);
@@ -124,7 +124,7 @@
   s << tag;
   s << " ";
   for (auto& arg : args) {
-    s << arg.to_string();
+    s << arg;
     s << " ";
   }
   tracebuffer::Add(s.str(), tracebuffer::kBegin);
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index 5d5b7cd..93c1b61 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -139,7 +139,7 @@
   return ::android::base::utf8::mkdir(path.c_str(), mode) == 0 || errno == EEXIST;
 }
 
-StringPiece GetStem(const StringPiece& path) {
+StringPiece GetStem(StringPiece path) {
   const char* start = path.begin();
   const char* end = path.end();
   for (const char* current = end - 1; current != start - 1; --current) {
@@ -150,7 +150,7 @@
   return {};
 }
 
-StringPiece GetFilename(const StringPiece& path) {
+StringPiece GetFilename(StringPiece path) {
   const char* end = path.end();
   const char* last_dir_sep = path.begin();
   for (const char* c = path.begin(); c != end; ++c) {
@@ -161,7 +161,7 @@
   return StringPiece(last_dir_sep, end - last_dir_sep);
 }
 
-StringPiece GetExtension(const StringPiece& path) {
+StringPiece GetExtension(StringPiece path) {
   StringPiece filename = GetFilename(path);
   const char* const end = filename.end();
   const char* c = std::find(filename.begin(), end, '.');
@@ -171,7 +171,7 @@
   return {};
 }
 
-bool IsHidden(const android::StringPiece& path) {
+bool IsHidden(android::StringPiece path) {
   return util::StartsWith(GetFilename(path), ".");
 }
 
@@ -193,16 +193,16 @@
   if (args.empty()) {
     return "";
   }
-  std::string out = args[0].to_string();
+  std::string out{args[0]};
   for (int i = 1; i < args.size(); i++) {
     file::AppendPath(&out, args[i]);
   }
   return out;
 }
 
-std::string PackageToPath(const StringPiece& package) {
+std::string PackageToPath(StringPiece package) {
   std::string out_path;
-  for (const StringPiece& part : util::Tokenize(package, '.')) {
+  for (StringPiece part : util::Tokenize(package, '.')) {
     AppendPath(&out_path, part);
   }
   return out_path;
@@ -241,10 +241,10 @@
   return std::move(filemap);
 }
 
-bool AppendArgsFromFile(const StringPiece& path, std::vector<std::string>* out_arglist,
+bool AppendArgsFromFile(StringPiece path, std::vector<std::string>* out_arglist,
                         std::string* out_error) {
   std::string contents;
-  if (!ReadFileToString(path.to_string(), &contents, true /*follow_symlinks*/)) {
+  if (!ReadFileToString(std::string(path), &contents, true /*follow_symlinks*/)) {
     if (out_error) {
       *out_error = "failed to read argument-list file";
     }
@@ -254,16 +254,16 @@
   for (StringPiece line : util::Tokenize(contents, ' ')) {
     line = util::TrimWhitespace(line);
     if (!line.empty()) {
-      out_arglist->push_back(line.to_string());
+      out_arglist->emplace_back(line);
     }
   }
   return true;
 }
 
-bool AppendSetArgsFromFile(const StringPiece& path, std::unordered_set<std::string>* out_argset,
+bool AppendSetArgsFromFile(StringPiece path, std::unordered_set<std::string>* out_argset,
                            std::string* out_error) {
   std::string contents;
-  if(!ReadFileToString(path.to_string(), &contents, true /*follow_symlinks*/)) {
+  if (!ReadFileToString(std::string(path), &contents, true /*follow_symlinks*/)) {
     if (out_error) {
       *out_error = "failed to read argument-list file";
     }
@@ -273,13 +273,13 @@
   for (StringPiece line : util::Tokenize(contents, ' ')) {
     line = util::TrimWhitespace(line);
     if (!line.empty()) {
-      out_argset->insert(line.to_string());
+      out_argset->emplace(line);
     }
   }
   return true;
 }
 
-bool FileFilter::SetPattern(const StringPiece& pattern) {
+bool FileFilter::SetPattern(StringPiece pattern) {
   pattern_tokens_ = util::SplitAndLowercase(pattern, ':');
   return true;
 }
@@ -343,10 +343,10 @@
   return true;
 }
 
-std::optional<std::vector<std::string>> FindFiles(const android::StringPiece& path,
+std::optional<std::vector<std::string>> FindFiles(android::StringPiece path,
                                                   android::IDiagnostics* diag,
                                                   const FileFilter* filter) {
-  const std::string root_dir = path.to_string();
+  const auto& root_dir = path;
   std::unique_ptr<DIR, decltype(closedir)*> d(opendir(root_dir.data()), closedir);
   if (!d) {
     diag->Error(android::DiagMessage() << SystemErrorCodeToString(errno) << ": " << root_dir);
@@ -361,7 +361,7 @@
     }
 
     std::string file_name = entry->d_name;
-    std::string full_path = root_dir;
+    std::string full_path{root_dir};
     AppendPath(&full_path, file_name);
     const FileType file_type = GetFileType(full_path);
 
@@ -380,7 +380,7 @@
 
   // Now process subdirs.
   for (const std::string& subdir : subdirs) {
-    std::string full_subdir = root_dir;
+    std::string full_subdir{root_dir};
     AppendPath(&full_subdir, subdir);
     std::optional<std::vector<std::string>> subfiles = FindFiles(full_subdir, diag, filter);
     if (!subfiles) {
diff --git a/tools/aapt2/util/Files.h b/tools/aapt2/util/Files.h
index ee95712..42eeaf2 100644
--- a/tools/aapt2/util/Files.h
+++ b/tools/aapt2/util/Files.h
@@ -66,31 +66,31 @@
 bool mkdirs(const std::string& path);
 
 // Returns all but the last part of the path.
-android::StringPiece GetStem(const android::StringPiece& path);
+android::StringPiece GetStem(android::StringPiece path);
 
 // Returns the last part of the path with extension.
-android::StringPiece GetFilename(const android::StringPiece& path);
+android::StringPiece GetFilename(android::StringPiece path);
 
 // Returns the extension of the path. This is the entire string after the first '.' of the last part
 // of the path.
-android::StringPiece GetExtension(const android::StringPiece& path);
+android::StringPiece GetExtension(android::StringPiece path);
 
 // Returns whether or not the name of the file or directory is a hidden file name
-bool IsHidden(const android::StringPiece& path);
+bool IsHidden(android::StringPiece path);
 
 // Converts a package name (com.android.app) to a path: com/android/app
-std::string PackageToPath(const android::StringPiece& package);
+std::string PackageToPath(android::StringPiece package);
 
 // Creates a FileMap for the file at path.
 std::optional<android::FileMap> MmapPath(const std::string& path, std::string* out_error);
 
 // Reads the file at path and appends each line to the outArgList vector.
-bool AppendArgsFromFile(const android::StringPiece& path, std::vector<std::string>* out_arglist,
+bool AppendArgsFromFile(android::StringPiece path, std::vector<std::string>* out_arglist,
                         std::string* out_error);
 
 // Reads the file at path and appends each line to the outargset set.
-bool AppendSetArgsFromFile(const android::StringPiece& path,
-                        std::unordered_set<std::string>* out_argset, std::string* out_error);
+bool AppendSetArgsFromFile(android::StringPiece path, std::unordered_set<std::string>* out_argset,
+                           std::string* out_error);
 
 // Filter that determines which resource files/directories are
 // processed by AAPT. Takes a pattern string supplied by the user.
@@ -112,7 +112,7 @@
   // - The special filenames "." and ".." are always ignored.
   // - Otherwise the full string is matched.
   // - match is not case-sensitive.
-  bool SetPattern(const android::StringPiece& pattern);
+  bool SetPattern(android::StringPiece pattern);
 
   // Applies the filter, returning true for pass, false for fail.
   bool operator()(const std::string& filename, FileType type) const;
@@ -126,7 +126,7 @@
 
 // Returns a list of files relative to the directory identified by `path`.
 // An optional FileFilter filters out any files that don't pass.
-std::optional<std::vector<std::string>> FindFiles(const android::StringPiece& path,
+std::optional<std::vector<std::string>> FindFiles(android::StringPiece path,
                                                   android::IDiagnostics* diag,
                                                   const FileFilter* filter = nullptr);
 
diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index 9b7ebdd..be87766 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -43,15 +43,14 @@
 // See frameworks/base/core/java/android/content/pm/parsing/ParsingPackageUtils.java
 constexpr static const size_t kMaxPackageNameSize = 223;
 
-static std::vector<std::string> SplitAndTransform(
-    const StringPiece& str, char sep, const std::function<char(char)>& f) {
+static std::vector<std::string> SplitAndTransform(StringPiece str, char sep, char (*f)(char)) {
   std::vector<std::string> parts;
   const StringPiece::const_iterator end = std::end(str);
   StringPiece::const_iterator start = std::begin(str);
   StringPiece::const_iterator current;
   do {
     current = std::find(start, end, sep);
-    parts.emplace_back(str.substr(start, current).to_string());
+    parts.emplace_back(start, current);
     if (f) {
       std::string& part = parts.back();
       std::transform(part.begin(), part.end(), part.begin(), f);
@@ -61,29 +60,29 @@
   return parts;
 }
 
-std::vector<std::string> Split(const StringPiece& str, char sep) {
+std::vector<std::string> Split(StringPiece str, char sep) {
   return SplitAndTransform(str, sep, nullptr);
 }
 
-std::vector<std::string> SplitAndLowercase(const StringPiece& str, char sep) {
-  return SplitAndTransform(str, sep, ::tolower);
+std::vector<std::string> SplitAndLowercase(StringPiece str, char sep) {
+  return SplitAndTransform(str, sep, [](char c) -> char { return ::tolower(c); });
 }
 
-bool StartsWith(const StringPiece& str, const StringPiece& prefix) {
+bool StartsWith(StringPiece str, StringPiece prefix) {
   if (str.size() < prefix.size()) {
     return false;
   }
   return str.substr(0, prefix.size()) == prefix;
 }
 
-bool EndsWith(const StringPiece& str, const StringPiece& suffix) {
+bool EndsWith(StringPiece str, StringPiece suffix) {
   if (str.size() < suffix.size()) {
     return false;
   }
   return str.substr(str.size() - suffix.size(), suffix.size()) == suffix;
 }
 
-StringPiece TrimLeadingWhitespace(const StringPiece& str) {
+StringPiece TrimLeadingWhitespace(StringPiece str) {
   if (str.size() == 0 || str.data() == nullptr) {
     return str;
   }
@@ -97,7 +96,7 @@
   return StringPiece(start, end - start);
 }
 
-StringPiece TrimTrailingWhitespace(const StringPiece& str) {
+StringPiece TrimTrailingWhitespace(StringPiece str) {
   if (str.size() == 0 || str.data() == nullptr) {
     return str;
   }
@@ -111,7 +110,7 @@
   return StringPiece(start, end - start);
 }
 
-StringPiece TrimWhitespace(const StringPiece& str) {
+StringPiece TrimWhitespace(StringPiece str) {
   if (str.size() == 0 || str.data() == nullptr) {
     return str;
   }
@@ -130,9 +129,9 @@
   return StringPiece(start, end - start);
 }
 
-static int IsJavaNameImpl(const StringPiece& str) {
+static int IsJavaNameImpl(StringPiece str) {
   int pieces = 0;
-  for (const StringPiece& piece : Tokenize(str, '.')) {
+  for (StringPiece piece : Tokenize(str, '.')) {
     pieces++;
     if (!text::IsJavaIdentifier(piece)) {
       return -1;
@@ -141,17 +140,17 @@
   return pieces;
 }
 
-bool IsJavaClassName(const StringPiece& str) {
+bool IsJavaClassName(StringPiece str) {
   return IsJavaNameImpl(str) >= 2;
 }
 
-bool IsJavaPackageName(const StringPiece& str) {
+bool IsJavaPackageName(StringPiece str) {
   return IsJavaNameImpl(str) >= 1;
 }
 
-static int IsAndroidNameImpl(const StringPiece& str) {
+static int IsAndroidNameImpl(StringPiece str) {
   int pieces = 0;
-  for (const StringPiece& piece : Tokenize(str, '.')) {
+  for (StringPiece piece : Tokenize(str, '.')) {
     if (piece.empty()) {
       return -1;
     }
@@ -173,15 +172,14 @@
   return pieces;
 }
 
-bool IsAndroidPackageName(const StringPiece& str) {
+bool IsAndroidPackageName(StringPiece str) {
   if (str.size() > kMaxPackageNameSize) {
     return false;
   }
   return IsAndroidNameImpl(str) > 1 || str == "android";
 }
 
-bool IsAndroidSharedUserId(const android::StringPiece& package_name,
-                           const android::StringPiece& shared_user_id) {
+bool IsAndroidSharedUserId(android::StringPiece package_name, android::StringPiece shared_user_id) {
   if (shared_user_id.size() > kMaxPackageNameSize) {
     return false;
   }
@@ -189,25 +187,24 @@
          package_name == "android";
 }
 
-bool IsAndroidSplitName(const StringPiece& str) {
+bool IsAndroidSplitName(StringPiece str) {
   return IsAndroidNameImpl(str) > 0;
 }
 
-std::optional<std::string> GetFullyQualifiedClassName(const StringPiece& package,
-                                                      const StringPiece& classname) {
+std::optional<std::string> GetFullyQualifiedClassName(StringPiece package, StringPiece classname) {
   if (classname.empty()) {
     return {};
   }
 
   if (util::IsJavaClassName(classname)) {
-    return classname.to_string();
+    return std::string(classname);
   }
 
   if (package.empty()) {
     return {};
   }
 
-  std::string result = package.to_string();
+  std::string result{package};
   if (classname.data()[0] != '.') {
     result += '.';
   }
@@ -251,7 +248,7 @@
   return static_cast<size_t>(c - start);
 }
 
-bool VerifyJavaStringFormat(const StringPiece& str) {
+bool VerifyJavaStringFormat(StringPiece str) {
   const char* c = str.begin();
   const char* const end = str.end();
 
@@ -341,7 +338,7 @@
   return true;
 }
 
-std::u16string Utf8ToUtf16(const StringPiece& utf8) {
+std::u16string Utf8ToUtf16(StringPiece utf8) {
   ssize_t utf16_length = utf8_to_utf16_length(
       reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length());
   if (utf16_length <= 0) {
@@ -381,7 +378,7 @@
   const char* end = str_.end();
   if (start == end) {
     end_ = true;
-    token_.assign(token_.end(), 0);
+    token_ = StringPiece(token_.end(), 0);
     return *this;
   }
 
@@ -389,12 +386,12 @@
   const char* current = start;
   while (current != end) {
     if (*current == separator_) {
-      token_.assign(start, current - start);
+      token_ = StringPiece(start, current - start);
       return *this;
     }
     ++current;
   }
-  token_.assign(start, end - start);
+  token_ = StringPiece(start, end - start);
   return *this;
 }
 
@@ -409,15 +406,17 @@
   return !(*this == rhs);
 }
 
-Tokenizer::iterator::iterator(const StringPiece& s, char sep, const StringPiece& tok, bool end)
-    : str_(s), separator_(sep), token_(tok), end_(end) {}
+Tokenizer::iterator::iterator(StringPiece s, char sep, StringPiece tok, bool end)
+    : str_(s), separator_(sep), token_(tok), end_(end) {
+}
 
-Tokenizer::Tokenizer(const StringPiece& str, char sep)
+Tokenizer::Tokenizer(StringPiece str, char sep)
     : begin_(++iterator(str, sep, StringPiece(str.begin() - 1, 0), false)),
-      end_(str, sep, StringPiece(str.end(), 0), true) {}
+      end_(str, sep, StringPiece(str.end(), 0), true) {
+}
 
-bool ExtractResFilePathParts(const StringPiece& path, StringPiece* out_prefix,
-                             StringPiece* out_entry, StringPiece* out_suffix) {
+bool ExtractResFilePathParts(StringPiece path, StringPiece* out_prefix, StringPiece* out_entry,
+                             StringPiece* out_suffix) {
   const StringPiece res_prefix("res/");
   if (!StartsWith(path, res_prefix)) {
     return false;
diff --git a/tools/aapt2/util/Util.h b/tools/aapt2/util/Util.h
index 8d3b413..40ff5b6 100644
--- a/tools/aapt2/util/Util.h
+++ b/tools/aapt2/util/Util.h
@@ -48,44 +48,44 @@
   T end;
 };
 
-std::vector<std::string> Split(const android::StringPiece& str, char sep);
-std::vector<std::string> SplitAndLowercase(const android::StringPiece& str, char sep);
+std::vector<std::string> Split(android::StringPiece str, char sep);
+std::vector<std::string> SplitAndLowercase(android::StringPiece str, char sep);
 
 // Returns true if the string starts with prefix.
-bool StartsWith(const android::StringPiece& str, const android::StringPiece& prefix);
+bool StartsWith(android::StringPiece str, android::StringPiece prefix);
 
 // Returns true if the string ends with suffix.
-bool EndsWith(const android::StringPiece& str, const android::StringPiece& suffix);
+bool EndsWith(android::StringPiece str, android::StringPiece suffix);
 
 // Creates a new StringPiece that points to a substring of the original string without leading
 // whitespace.
-android::StringPiece TrimLeadingWhitespace(const android::StringPiece& str);
+android::StringPiece TrimLeadingWhitespace(android::StringPiece str);
 
 // Creates a new StringPiece that points to a substring of the original string without trailing
 // whitespace.
-android::StringPiece TrimTrailingWhitespace(const android::StringPiece& str);
+android::StringPiece TrimTrailingWhitespace(android::StringPiece str);
 
 // Creates a new StringPiece that points to a substring of the original string without leading or
 // trailing whitespace.
-android::StringPiece TrimWhitespace(const android::StringPiece& str);
+android::StringPiece TrimWhitespace(android::StringPiece str);
 
 // Tests that the string is a valid Java class name.
-bool IsJavaClassName(const android::StringPiece& str);
+bool IsJavaClassName(android::StringPiece str);
 
 // Tests that the string is a valid Java package name.
-bool IsJavaPackageName(const android::StringPiece& str);
+bool IsJavaPackageName(android::StringPiece str);
 
 // Tests that the string is a valid Android package name. More strict than a Java package name.
 // - First character of each component (separated by '.') must be an ASCII letter.
 // - Subsequent characters of a component can be ASCII alphanumeric or an underscore.
 // - Package must contain at least two components, unless it is 'android'.
 // - The maximum package name length is 223.
-bool IsAndroidPackageName(const android::StringPiece& str);
+bool IsAndroidPackageName(android::StringPiece str);
 
 // Tests that the string is a valid Android split name.
 // - First character of each component (separated by '.') must be an ASCII letter.
 // - Subsequent characters of a component can be ASCII alphanumeric or an underscore.
-bool IsAndroidSplitName(const android::StringPiece& str);
+bool IsAndroidSplitName(android::StringPiece str);
 
 // Tests that the string is a valid Android shared user id.
 // - First character of each component (separated by '.') must be an ASCII letter.
@@ -93,8 +93,7 @@
 // - Must contain at least two components, unless package name is 'android'.
 // - The maximum shared user id length is 223.
 // - Treat empty string as valid, it's the case of no shared user id.
-bool IsAndroidSharedUserId(const android::StringPiece& package_name,
-                           const android::StringPiece& shared_user_id);
+bool IsAndroidSharedUserId(android::StringPiece package_name, android::StringPiece shared_user_id);
 
 // Converts the class name to a fully qualified class name from the given
 // `package`. Ex:
@@ -103,8 +102,8 @@
 // .asdf        --> package.asdf
 // .a.b         --> package.a.b
 // asdf.adsf    --> asdf.adsf
-std::optional<std::string> GetFullyQualifiedClassName(const android::StringPiece& package,
-                                                      const android::StringPiece& class_name);
+std::optional<std::string> GetFullyQualifiedClassName(android::StringPiece package,
+                                                      android::StringPiece class_name);
 
 // Retrieves the formatted name of aapt2.
 const char* GetToolName();
@@ -152,16 +151,16 @@
 // explicitly specifying an index) when there are more than one argument. This is an error
 // because translations may rearrange the order of the arguments in the string, which will
 // break the string interpolation.
-bool VerifyJavaStringFormat(const android::StringPiece& str);
+bool VerifyJavaStringFormat(android::StringPiece str);
 
-bool AppendStyledString(const android::StringPiece& input, bool preserve_spaces,
-                        std::string* out_str, std::string* out_error);
+bool AppendStyledString(android::StringPiece input, bool preserve_spaces, std::string* out_str,
+                        std::string* out_error);
 
 class StringBuilder {
  public:
   StringBuilder() = default;
 
-  StringBuilder& Append(const android::StringPiece& str);
+  StringBuilder& Append(android::StringPiece str);
   const std::string& ToString() const;
   const std::string& Error() const;
   bool IsEmpty() const;
@@ -229,7 +228,7 @@
    private:
     friend class Tokenizer;
 
-    iterator(const android::StringPiece& s, char sep, const android::StringPiece& tok, bool end);
+    iterator(android::StringPiece s, char sep, android::StringPiece tok, bool end);
 
     android::StringPiece str_;
     char separator_;
@@ -237,7 +236,7 @@
     bool end_;
   };
 
-  Tokenizer(const android::StringPiece& str, char sep);
+  Tokenizer(android::StringPiece str, char sep);
 
   iterator begin() const {
     return begin_;
@@ -252,7 +251,7 @@
   const iterator end_;
 };
 
-inline Tokenizer Tokenize(const android::StringPiece& str, char sep) {
+inline Tokenizer Tokenize(android::StringPiece str, char sep) {
   return Tokenizer(str, sep);
 }
 
@@ -263,7 +262,7 @@
 // Extracts ".xml" into outSuffix.
 //
 // Returns true if successful.
-bool ExtractResFilePathParts(const android::StringPiece& path, android::StringPiece* out_prefix,
+bool ExtractResFilePathParts(android::StringPiece path, android::StringPiece* out_prefix,
                              android::StringPiece* out_entry, android::StringPiece* out_suffix);
 
 }  // namespace util
diff --git a/tools/aapt2/util/Util_test.cpp b/tools/aapt2/util/Util_test.cpp
index 4ebcb11..15135690 100644
--- a/tools/aapt2/util/Util_test.cpp
+++ b/tools/aapt2/util/Util_test.cpp
@@ -84,6 +84,14 @@
   ASSERT_THAT(*iter, Eq(StringPiece()));
 }
 
+TEST(UtilTest, TokenizeNone) {
+  auto tokenizer = util::Tokenize(StringPiece("none"), '.');
+  auto iter = tokenizer.begin();
+  ASSERT_THAT(*iter, Eq("none"));
+  ++iter;
+  ASSERT_THAT(iter, Eq(tokenizer.end()));
+}
+
 TEST(UtilTest, IsJavaClassName) {
   EXPECT_TRUE(util::IsJavaClassName("android.test.Class"));
   EXPECT_TRUE(util::IsJavaClassName("android.test.Class$Inner"));
diff --git a/tools/aapt2/xml/XmlActionExecutor.cpp b/tools/aapt2/xml/XmlActionExecutor.cpp
index 9bdbd22..3ccbaa2 100644
--- a/tools/aapt2/xml/XmlActionExecutor.cpp
+++ b/tools/aapt2/xml/XmlActionExecutor.cpp
@@ -84,7 +84,7 @@
         error_msg << "unexpected element ";
         PrintElementToDiagMessage(child_el, &error_msg);
         error_msg << " found in ";
-        for (const StringPiece& element : *bread_crumb) {
+        for (StringPiece element : *bread_crumb) {
           error_msg << "<" << element << ">";
         }
         if (policy == XmlActionExecutorPolicy::kAllowListWarning) {
diff --git a/tools/aapt2/xml/XmlDom.cpp b/tools/aapt2/xml/XmlDom.cpp
index f51e8a4..8dea8ea 100644
--- a/tools/aapt2/xml/XmlDom.cpp
+++ b/tools/aapt2/xml/XmlDom.cpp
@@ -169,7 +169,7 @@
   stack->last_text_node = util::make_unique<Text>();
   stack->last_text_node->line_number = XML_GetCurrentLineNumber(parser);
   stack->last_text_node->column_number = XML_GetCurrentColumnNumber(parser);
-  stack->last_text_node->text = str.to_string();
+  stack->last_text_node->text.assign(str);
 }
 
 static void XMLCALL CommentDataHandler(void* user_data, const char* comment) {
@@ -417,11 +417,11 @@
   children.insert(children.begin() + index, std::move(child));
 }
 
-Attribute* Element::FindAttribute(const StringPiece& ns, const StringPiece& name) {
+Attribute* Element::FindAttribute(StringPiece ns, StringPiece name) {
   return const_cast<Attribute*>(static_cast<const Element*>(this)->FindAttribute(ns, name));
 }
 
-const Attribute* Element::FindAttribute(const StringPiece& ns, const StringPiece& name) const {
+const Attribute* Element::FindAttribute(StringPiece ns, StringPiece name) const {
   for (const auto& attr : attributes) {
     if (ns == attr.namespace_uri && name == attr.name) {
       return &attr;
@@ -430,7 +430,7 @@
   return nullptr;
 }
 
-void Element::RemoveAttribute(const StringPiece& ns, const StringPiece& name) {
+void Element::RemoveAttribute(StringPiece ns, StringPiece name) {
   auto new_attr_end = std::remove_if(attributes.begin(), attributes.end(),
     [&](const Attribute& attr) -> bool {
       return ns == attr.namespace_uri && name == attr.name;
@@ -439,34 +439,32 @@
   attributes.erase(new_attr_end, attributes.end());
 }
 
-Attribute* Element::FindOrCreateAttribute(const StringPiece& ns, const StringPiece& name) {
+Attribute* Element::FindOrCreateAttribute(StringPiece ns, StringPiece name) {
   Attribute* attr = FindAttribute(ns, name);
   if (attr == nullptr) {
-    attributes.push_back(Attribute{ns.to_string(), name.to_string()});
+    attributes.push_back(Attribute{std::string(ns), std::string(name)});
     attr = &attributes.back();
   }
   return attr;
 }
 
-Element* Element::FindChild(const StringPiece& ns, const StringPiece& name) {
+Element* Element::FindChild(StringPiece ns, StringPiece name) {
   return FindChildWithAttribute(ns, name, {}, {}, {});
 }
 
-const Element* Element::FindChild(const StringPiece& ns, const StringPiece& name) const {
+const Element* Element::FindChild(StringPiece ns, StringPiece name) const {
   return FindChildWithAttribute(ns, name, {}, {}, {});
 }
 
-Element* Element::FindChildWithAttribute(const StringPiece& ns, const StringPiece& name,
-                                         const StringPiece& attr_ns, const StringPiece& attr_name,
-                                         const StringPiece& attr_value) {
+Element* Element::FindChildWithAttribute(StringPiece ns, StringPiece name, StringPiece attr_ns,
+                                         StringPiece attr_name, StringPiece attr_value) {
   return const_cast<Element*>(static_cast<const Element*>(this)->FindChildWithAttribute(
       ns, name, attr_ns, attr_name, attr_value));
 }
 
-const Element* Element::FindChildWithAttribute(const StringPiece& ns, const StringPiece& name,
-                                               const StringPiece& attr_ns,
-                                               const StringPiece& attr_name,
-                                               const StringPiece& attr_value) const {
+const Element* Element::FindChildWithAttribute(StringPiece ns, StringPiece name,
+                                               StringPiece attr_ns, StringPiece attr_name,
+                                               StringPiece attr_value) const {
   for (const auto& child : children) {
     if (const Element* el = NodeCast<Element>(child.get())) {
       if (ns == el->namespace_uri && name == el->name) {
@@ -559,7 +557,7 @@
 }
 
 std::optional<ExtractedPackage> PackageAwareVisitor::TransformPackageAlias(
-    const StringPiece& alias) const {
+    StringPiece alias) const {
   if (alias.empty()) {
     return ExtractedPackage{{}, false /*private*/};
   }
diff --git a/tools/aapt2/xml/XmlDom.h b/tools/aapt2/xml/XmlDom.h
index 5bc55b6..c253b0a 100644
--- a/tools/aapt2/xml/XmlDom.h
+++ b/tools/aapt2/xml/XmlDom.h
@@ -96,27 +96,22 @@
   void AppendChild(std::unique_ptr<Node> child);
   void InsertChild(size_t index, std::unique_ptr<Node> child);
 
-  Attribute* FindAttribute(const android::StringPiece& ns, const android::StringPiece& name);
-  const Attribute* FindAttribute(const android::StringPiece& ns,
-                                 const android::StringPiece& name) const;
-  Attribute* FindOrCreateAttribute(const android::StringPiece& ns,
-                                   const android::StringPiece& name);
-  void RemoveAttribute(const android::StringPiece& ns,
-                       const android::StringPiece& name);
+  Attribute* FindAttribute(android::StringPiece ns, android::StringPiece name);
+  const Attribute* FindAttribute(android::StringPiece ns, android::StringPiece name) const;
+  Attribute* FindOrCreateAttribute(android::StringPiece ns, android::StringPiece name);
+  void RemoveAttribute(android::StringPiece ns, android::StringPiece name);
 
-  Element* FindChild(const android::StringPiece& ns, const android::StringPiece& name);
-  const Element* FindChild(const android::StringPiece& ns, const android::StringPiece& name) const;
+  Element* FindChild(android::StringPiece ns, android::StringPiece name);
+  const Element* FindChild(android::StringPiece ns, android::StringPiece name) const;
 
-  Element* FindChildWithAttribute(const android::StringPiece& ns, const android::StringPiece& name,
-                                  const android::StringPiece& attr_ns,
-                                  const android::StringPiece& attr_name,
-                                  const android::StringPiece& attr_value);
+  Element* FindChildWithAttribute(android::StringPiece ns, android::StringPiece name,
+                                  android::StringPiece attr_ns, android::StringPiece attr_name,
+                                  android::StringPiece attr_value);
 
-  const Element* FindChildWithAttribute(const android::StringPiece& ns,
-                                        const android::StringPiece& name,
-                                        const android::StringPiece& attr_ns,
-                                        const android::StringPiece& attr_name,
-                                        const android::StringPiece& attr_value) const;
+  const Element* FindChildWithAttribute(android::StringPiece ns, android::StringPiece name,
+                                        android::StringPiece attr_ns,
+                                        android::StringPiece attr_name,
+                                        android::StringPiece attr_value) const;
 
   std::vector<Element*> GetChildElements();
 
@@ -235,8 +230,7 @@
  public:
   using Visitor::Visit;
 
-  std::optional<ExtractedPackage> TransformPackageAlias(
-      const android::StringPiece& alias) const override;
+  std::optional<ExtractedPackage> TransformPackageAlias(android::StringPiece alias) const override;
 
  protected:
   PackageAwareVisitor() = default;
diff --git a/tools/aapt2/xml/XmlPullParser.cpp b/tools/aapt2/xml/XmlPullParser.cpp
index bfa0749..d79446b 100644
--- a/tools/aapt2/xml/XmlPullParser.cpp
+++ b/tools/aapt2/xml/XmlPullParser.cpp
@@ -140,8 +140,7 @@
   return event_queue_.front().data2;
 }
 
-std::optional<ExtractedPackage> XmlPullParser::TransformPackageAlias(
-    const StringPiece& alias) const {
+std::optional<ExtractedPackage> XmlPullParser::TransformPackageAlias(StringPiece alias) const {
   if (alias.empty()) {
     return ExtractedPackage{{}, false /*private*/};
   }
@@ -307,7 +306,7 @@
                                       parser->depth_ });
 }
 
-std::optional<StringPiece> FindAttribute(const XmlPullParser* parser, const StringPiece& name) {
+std::optional<StringPiece> FindAttribute(const XmlPullParser* parser, StringPiece name) {
   auto iter = parser->FindAttribute("", name);
   if (iter != parser->end_attributes()) {
     return StringPiece(util::TrimWhitespace(iter->value));
@@ -315,8 +314,7 @@
   return {};
 }
 
-std::optional<StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser,
-                                                 const StringPiece& name) {
+std::optional<StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser, StringPiece name) {
   auto iter = parser->FindAttribute("", name);
   if (iter != parser->end_attributes()) {
     StringPiece trimmed = util::TrimWhitespace(iter->value);
diff --git a/tools/aapt2/xml/XmlPullParser.h b/tools/aapt2/xml/XmlPullParser.h
index ab34772..fe4cd01 100644
--- a/tools/aapt2/xml/XmlPullParser.h
+++ b/tools/aapt2/xml/XmlPullParser.h
@@ -120,8 +120,7 @@
    * If xmlns:app="http://schemas.android.com/apk/res-auto", then
    * 'package' will be set to 'defaultPackage'.
    */
-  std::optional<ExtractedPackage> TransformPackageAlias(
-      const android::StringPiece& alias) const override;
+  std::optional<ExtractedPackage> TransformPackageAlias(android::StringPiece alias) const override;
 
   struct PackageDecl {
     std::string prefix;
@@ -194,7 +193,7 @@
  * Finds the attribute in the current element within the global namespace.
  */
 std::optional<android::StringPiece> FindAttribute(const XmlPullParser* parser,
-                                                  const android::StringPiece& name);
+                                                  android::StringPiece name);
 
 /**
  * Finds the attribute in the current element within the global namespace. The
@@ -202,7 +201,7 @@
  * must not be the empty string.
  */
 std::optional<android::StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser,
-                                                          const android::StringPiece& name);
+                                                          android::StringPiece name);
 
 //
 // Implementation
diff --git a/tools/aapt2/xml/XmlUtil.cpp b/tools/aapt2/xml/XmlUtil.cpp
index 114b5ba..709755e 100644
--- a/tools/aapt2/xml/XmlUtil.cpp
+++ b/tools/aapt2/xml/XmlUtil.cpp
@@ -27,7 +27,7 @@
 namespace aapt {
 namespace xml {
 
-std::string BuildPackageNamespace(const StringPiece& package, bool private_reference) {
+std::string BuildPackageNamespace(StringPiece package, bool private_reference) {
   std::string result = private_reference ? kSchemaPrivatePrefix : kSchemaPublicPrefix;
   result.append(package.data(), package.size());
   return result;
@@ -41,7 +41,7 @@
     if (package.empty()) {
       return {};
     }
-    return ExtractedPackage{package.to_string(), false /* is_private */};
+    return ExtractedPackage{std::string(package), false /* is_private */};
 
   } else if (util::StartsWith(namespace_uri, kSchemaPrivatePrefix)) {
     StringPiece schema_prefix = kSchemaPrivatePrefix;
@@ -50,7 +50,7 @@
     if (package.empty()) {
       return {};
     }
-    return ExtractedPackage{package.to_string(), true /* is_private */};
+    return ExtractedPackage{std::string(package), true /* is_private */};
 
   } else if (namespace_uri == kSchemaAuto) {
     return ExtractedPackage{std::string(), true /* is_private */};
diff --git a/tools/aapt2/xml/XmlUtil.h b/tools/aapt2/xml/XmlUtil.h
index 1ab05a9..ad676ca 100644
--- a/tools/aapt2/xml/XmlUtil.h
+++ b/tools/aapt2/xml/XmlUtil.h
@@ -59,8 +59,7 @@
 //
 // If privateReference == true, the package will be of the form:
 //   http://schemas.android.com/apk/prv/res/<package>
-std::string BuildPackageNamespace(const android::StringPiece& package,
-                                  bool private_reference = false);
+std::string BuildPackageNamespace(android::StringPiece package, bool private_reference = false);
 
 // Interface representing a stack of XML namespace declarations. When looking up the package for a
 // namespace prefix, the stack is checked from top to bottom.
@@ -69,7 +68,7 @@
 
   // Returns an ExtractedPackage struct if the alias given corresponds with a package declaration.
   virtual std::optional<ExtractedPackage> TransformPackageAlias(
-      const android::StringPiece& alias) const = 0;
+      android::StringPiece alias) const = 0;
 };
 
 // Helper function for transforming the original Reference inRef to a fully qualified reference