idmap2: switch to improved Result class

Remove the old std::optional based Result class, replace uses with the
new std::variant based Result class.

Test: make idmap2_tests
Change-Id: I401cb36e5af06133a2872d835cf29bfb0b106597
diff --git a/cmds/idmap2/tests/FileUtilsTests.cpp b/cmds/idmap2/tests/FileUtilsTests.cpp
index 2e85eb6..34a0097 100644
--- a/cmds/idmap2/tests/FileUtilsTests.cpp
+++ b/cmds/idmap2/tests/FileUtilsTests.cpp
@@ -58,21 +58,15 @@
   });
   ASSERT_THAT(v, NotNull());
   ASSERT_EQ(v->size(), 10U);
-  ASSERT_EQ(
-      std::set<std::string>(v->begin(), v->end()),
-      std::set<std::string>(
-          {
-              root + "/target/target.apk",
-              root + "/target/target-no-overlayable.apk",
-              root + "/overlay/overlay.apk",
-              root + "/overlay/overlay-no-name.apk",
-              root + "/overlay/overlay-no-name-static.apk",
-              root + "/overlay/overlay-static-1.apk",
-              root + "/overlay/overlay-static-2.apk",
-              root + "/signature-overlay/signature-overlay.apk",
-              root + "/system-overlay/system-overlay.apk",
-              root + "/system-overlay-invalid/system-overlay-invalid.apk"
-          }));
+  ASSERT_EQ(std::set<std::string>(v->begin(), v->end()),
+            std::set<std::string>(
+                {root + "/target/target.apk", root + "/target/target-no-overlayable.apk",
+                 root + "/overlay/overlay.apk", root + "/overlay/overlay-no-name.apk",
+                 root + "/overlay/overlay-no-name-static.apk",
+                 root + "/overlay/overlay-static-1.apk", root + "/overlay/overlay-static-2.apk",
+                 root + "/signature-overlay/signature-overlay.apk",
+                 root + "/system-overlay/system-overlay.apk",
+                 root + "/system-overlay-invalid/system-overlay-invalid.apk"}));
 }
 
 TEST(FileUtilsTests, ReadFile) {
diff --git a/cmds/idmap2/tests/IdmapTests.cpp b/cmds/idmap2/tests/IdmapTests.cpp
index 53ec03b..bbfbad9 100644
--- a/cmds/idmap2/tests/IdmapTests.cpp
+++ b/cmds/idmap2/tests/IdmapTests.cpp
@@ -256,10 +256,10 @@
   ASSERT_EQ(types[0]->GetOverlayTypeId(), 0x01U);
   ASSERT_EQ(types[0]->GetEntryCount(), 4U);
   ASSERT_EQ(types[0]->GetEntryOffset(), 6U);
-  ASSERT_EQ(types[0]->GetEntry(0), 0x0000U);  // string/policy_public
-  ASSERT_EQ(types[0]->GetEntry(1), kNoEntry); // string/policy_signature
-  ASSERT_EQ(types[0]->GetEntry(2), 0x0001U);  // string/policy_system
-  ASSERT_EQ(types[0]->GetEntry(3), 0x0002U);  // string/policy_system_vendor
+  ASSERT_EQ(types[0]->GetEntry(0), 0x0000U);   // string/policy_public
+  ASSERT_EQ(types[0]->GetEntry(1), kNoEntry);  // string/policy_signature
+  ASSERT_EQ(types[0]->GetEntry(2), 0x0001U);   // string/policy_system
+  ASSERT_EQ(types[0]->GetEntry(3), 0x0002U);   // string/policy_system_vendor
 }
 
 TEST(IdmapOverlayableTests, CreateIdmapFromApkAssetsPolicySignature) {
@@ -267,7 +267,8 @@
   std::unique_ptr<const ApkAssets> target_apk = ApkAssets::Load(target_apk_path);
   ASSERT_THAT(target_apk, NotNull());
 
-  const std::string overlay_apk_path(GetTestDataPath() + "/signature-overlay/signature-overlay.apk");
+  const std::string overlay_apk_path(GetTestDataPath() +
+                                     "/signature-overlay/signature-overlay.apk");
   std::unique_ptr<const ApkAssets> overlay_apk = ApkAssets::Load(overlay_apk_path);
   ASSERT_THAT(overlay_apk, NotNull());
 
@@ -294,7 +295,7 @@
   ASSERT_EQ(types[0]->GetOverlayTypeId(), 0x01U);
   ASSERT_EQ(types[0]->GetEntryCount(), 1U);
   ASSERT_EQ(types[0]->GetEntryOffset(), 7U);
-  ASSERT_EQ(types[0]->GetEntry(0), 0x0000U); // string/policy_signature
+  ASSERT_EQ(types[0]->GetEntry(0), 0x0000U);  // string/policy_signature
 }
 
 TEST(IdmapOverlayableTests, CreateIdmapFromApkAssetsPolicySignatureNotFulfilled) {
@@ -302,7 +303,8 @@
   std::unique_ptr<const ApkAssets> target_apk = ApkAssets::Load(target_apk_path);
   ASSERT_THAT(target_apk, NotNull());
 
-  const std::string overlay_apk_path(GetTestDataPath() + "/signature-overlay/signature-overlay.apk");
+  const std::string overlay_apk_path(GetTestDataPath() +
+                                     "/signature-overlay/signature-overlay.apk");
   std::unique_ptr<const ApkAssets> overlay_apk = ApkAssets::Load(overlay_apk_path);
   ASSERT_THAT(overlay_apk, NotNull());
 
@@ -323,7 +325,7 @@
   ASSERT_EQ(data->GetHeader()->GetTypeCount(), 0U);
 
   const std::vector<std::unique_ptr<const IdmapData::TypeEntry>>& types = data->GetTypeEntries();
-  ASSERT_EQ(types.size(), 0U); // can't overlay, so contains nothing
+  ASSERT_EQ(types.size(), 0U);  // can't overlay, so contains nothing
 }
 
 // Overlays should abide by all overlayable restrictions if enforcement of overlayable is enabled.
@@ -359,10 +361,10 @@
   ASSERT_EQ(types[0]->GetOverlayTypeId(), 0x01U);
   ASSERT_EQ(types[0]->GetEntryCount(), 4U);
   ASSERT_EQ(types[0]->GetEntryOffset(), 6U);
-  ASSERT_EQ(types[0]->GetEntry(0), 0x0003U);  // string/policy_public
-  ASSERT_EQ(types[0]->GetEntry(1), kNoEntry); // string/policy_signature
-  ASSERT_EQ(types[0]->GetEntry(2), 0x0005U);  // string/policy_system
-  ASSERT_EQ(types[0]->GetEntry(3), 0x0006U);  // string/policy_system_vendor
+  ASSERT_EQ(types[0]->GetEntry(0), 0x0003U);   // string/policy_public
+  ASSERT_EQ(types[0]->GetEntry(1), kNoEntry);  // string/policy_signature
+  ASSERT_EQ(types[0]->GetEntry(2), 0x0005U);   // string/policy_system
+  ASSERT_EQ(types[0]->GetEntry(3), 0x0006U);   // string/policy_system_vendor
 }
 
 // Overlays should ignore all overlayable restrictions if enforcement of overlayable is disabled.
diff --git a/cmds/idmap2/tests/PoliciesTests.cpp b/cmds/idmap2/tests/PoliciesTests.cpp
index ab567ad..a76da53 100644
--- a/cmds/idmap2/tests/PoliciesTests.cpp
+++ b/cmds/idmap2/tests/PoliciesTests.cpp
@@ -27,44 +27,42 @@
 namespace android::idmap2 {
 
 TEST(PoliciesTests, PoliciesToBitmasks) {
-  const Result<PolicyBitmask> bitmask1 = PoliciesToBitmask({"system"}, std::cerr);
-  ASSERT_NE(bitmask1, kResultError);
-  ASSERT_EQ(bitmask1, PolicyFlags::POLICY_SYSTEM_PARTITION);
+  const auto bitmask1 = PoliciesToBitmask({"system"});
+  ASSERT_TRUE(bitmask1);
+  ASSERT_EQ(*bitmask1, PolicyFlags::POLICY_SYSTEM_PARTITION);
 
-  const Result<PolicyBitmask> bitmask2 = PoliciesToBitmask({"system", "vendor"}, std::cerr);
-  ASSERT_NE(bitmask2, kResultError);
-  ASSERT_EQ(bitmask2, PolicyFlags::POLICY_SYSTEM_PARTITION | PolicyFlags::POLICY_VENDOR_PARTITION);
+  const auto bitmask2 = PoliciesToBitmask({"system", "vendor"});
+  ASSERT_TRUE(bitmask2);
+  ASSERT_EQ(*bitmask2, PolicyFlags::POLICY_SYSTEM_PARTITION | PolicyFlags::POLICY_VENDOR_PARTITION);
 
-  const Result<PolicyBitmask> bitmask3 = PoliciesToBitmask({"vendor", "system"}, std::cerr);
-  ASSERT_NE(bitmask3, kResultError);
-  ASSERT_EQ(bitmask3, PolicyFlags::POLICY_SYSTEM_PARTITION | PolicyFlags::POLICY_VENDOR_PARTITION);
+  const auto bitmask3 = PoliciesToBitmask({"vendor", "system"});
+  ASSERT_TRUE(bitmask3);
+  ASSERT_EQ(*bitmask3, PolicyFlags::POLICY_SYSTEM_PARTITION | PolicyFlags::POLICY_VENDOR_PARTITION);
 
-  const Result<PolicyBitmask> bitmask4 =
-      PoliciesToBitmask({"public", "product", "system", "vendor"}, std::cerr);
-  ASSERT_NE(bitmask4, kResultError);
-  ASSERT_EQ(bitmask4, PolicyFlags::POLICY_PUBLIC | PolicyFlags::POLICY_PRODUCT_PARTITION |
-                          PolicyFlags::POLICY_SYSTEM_PARTITION |
-                          PolicyFlags::POLICY_VENDOR_PARTITION);
+  const auto bitmask4 = PoliciesToBitmask({"public", "product", "system", "vendor"});
+  ASSERT_TRUE(bitmask4);
+  ASSERT_EQ(*bitmask4, PolicyFlags::POLICY_PUBLIC | PolicyFlags::POLICY_PRODUCT_PARTITION |
+                           PolicyFlags::POLICY_SYSTEM_PARTITION |
+                           PolicyFlags::POLICY_VENDOR_PARTITION);
 
-  const Result<PolicyBitmask> bitmask5 =
-      PoliciesToBitmask({"system", "system", "system"}, std::cerr);
-  ASSERT_NE(bitmask5, kResultError);
-  ASSERT_EQ(bitmask5, PolicyFlags::POLICY_SYSTEM_PARTITION);
+  const auto bitmask5 = PoliciesToBitmask({"system", "system", "system"});
+  ASSERT_TRUE(bitmask5);
+  ASSERT_EQ(*bitmask5, PolicyFlags::POLICY_SYSTEM_PARTITION);
 
-  const Result<PolicyBitmask> bitmask6 = PoliciesToBitmask({""}, std::cerr);
-  ASSERT_EQ(bitmask6, kResultError);
+  const auto bitmask6 = PoliciesToBitmask({""});
+  ASSERT_FALSE(bitmask6);
 
-  const Result<PolicyBitmask> bitmask7 = PoliciesToBitmask({"foo"}, std::cerr);
-  ASSERT_EQ(bitmask7, kResultError);
+  const auto bitmask7 = PoliciesToBitmask({"foo"});
+  ASSERT_FALSE(bitmask7);
 
-  const Result<PolicyBitmask> bitmask8 = PoliciesToBitmask({"system", "foo"}, std::cerr);
-  ASSERT_EQ(bitmask8, kResultError);
+  const auto bitmask8 = PoliciesToBitmask({"system", "foo"});
+  ASSERT_FALSE(bitmask8);
 
-  const Result<PolicyBitmask> bitmask9 = PoliciesToBitmask({"system", ""}, std::cerr);
-  ASSERT_EQ(bitmask9, kResultError);
+  const auto bitmask9 = PoliciesToBitmask({"system", ""});
+  ASSERT_FALSE(bitmask9);
 
-  const Result<PolicyBitmask> bitmask10 = PoliciesToBitmask({"system "}, std::cerr);
-  ASSERT_EQ(bitmask10, kResultError);
+  const auto bitmask10 = PoliciesToBitmask({"system "});
+  ASSERT_FALSE(bitmask10);
 }
 
 }  // namespace android::idmap2
diff --git a/cmds/idmap2/tests/ResultTests.cpp b/cmds/idmap2/tests/ResultTests.cpp
index d82f0c4..5f4daed 100644
--- a/cmds/idmap2/tests/ResultTests.cpp
+++ b/cmds/idmap2/tests/ResultTests.cpp
@@ -32,28 +32,28 @@
 // Tests: Error
 
 TEST(ResultTests, ErrorTraits) {
-  ASSERT_TRUE(std::is_move_constructible<v2::Error>::value);
-  ASSERT_TRUE(std::is_move_assignable<v2::Error>::value);
-  ASSERT_TRUE(std::is_copy_constructible<v2::Error>::value);
-  ASSERT_TRUE(std::is_copy_assignable<v2::Error>::value);
+  ASSERT_TRUE(std::is_move_constructible<Error>::value);
+  ASSERT_TRUE(std::is_move_assignable<Error>::value);
+  ASSERT_TRUE(std::is_copy_constructible<Error>::value);
+  ASSERT_TRUE(std::is_copy_assignable<Error>::value);
 }
 
 TEST(ResultTests, ErrorCtorFormat) {
-  v2::Error e("%s=0x%08x", "resid", 0x7f010002);
+  Error e("%s=0x%08x", "resid", 0x7f010002);
   ASSERT_EQ(e.GetMessage(), "resid=0x7f010002");
 }
 
 TEST(ResultTests, ErrorPropagateParent) {
-  v2::Error e1("foo");
+  Error e1("foo");
   ASSERT_EQ(e1.GetMessage(), "foo");
 
-  v2::Error e2(e1, "bar");
+  Error e2(e1, "bar");
   ASSERT_EQ(e2.GetMessage(), "foo -> bar");
 
-  v2::Error e3(e2);  // NOLINT(performance-unnecessary-copy-initialization)
+  Error e3(e2);  // NOLINT(performance-unnecessary-copy-initialization)
   ASSERT_EQ(e3.GetMessage(), "foo -> bar");
 
-  v2::Error e4(e3, "%02d", 1);
+  Error e4(e3, "%02d", 1);
   ASSERT_EQ(e4.GetMessage(), "foo -> bar -> 01");
 }
 
@@ -61,13 +61,13 @@
 
 // Result(const Result&)
 TEST(ResultTests, CopyConstructor) {
-  v2::Result<uint32_t> r1(42U);
+  Result<uint32_t> r1(42U);
 
-  v2::Result<uint32_t> r2(r1);
+  Result<uint32_t> r2(r1);
   ASSERT_TRUE(r2);
   ASSERT_EQ(*r2, 42U);
 
-  v2::Result<uint32_t> r3 = r2;
+  Result<uint32_t> r3 = r2;
   ASSERT_TRUE(r3);
   ASSERT_EQ(*r3, 42U);
 }
@@ -75,23 +75,23 @@
 // Result(const T&)
 TEST(ResultTests, Constructor) {
   uint32_t v = 42U;
-  v2::Result<uint32_t> r1(v);
+  Result<uint32_t> r1(v);
   ASSERT_TRUE(r1);
   ASSERT_EQ(*r1, 42U);
 
-  v2::Error e("foo");
-  v2::Result<uint32_t> r2(e);
+  Error e("foo");
+  Result<uint32_t> r2(e);
   ASSERT_FALSE(r2);
   ASSERT_EQ(r2.GetErrorMessage(), "foo");
 }
 
 // Result(const T&&)
 TEST(ResultTests, MoveConstructor) {
-  v2::Result<uint32_t> r1(42U);
+  Result<uint32_t> r1(42U);
   ASSERT_TRUE(r1);
   ASSERT_EQ(*r1, 42U);
 
-  v2::Result<uint32_t> r2(v2::Error("foo"));
+  Result<uint32_t> r2(Error("foo"));
   ASSERT_FALSE(r2);
   ASSERT_EQ(r2.GetErrorMessage(), "foo");
 }
@@ -99,52 +99,52 @@
 // operator=
 TEST(ResultTests, CopyAssignmentOperator) {
   // note: 'Result<...> r2 = r1;' calls the copy ctor
-  v2::Result<uint32_t> r1(42U);
-  v2::Result<uint32_t> r2(0U);
+  Result<uint32_t> r1(42U);
+  Result<uint32_t> r2(0U);
   r2 = r1;
   ASSERT_TRUE(r2);
   ASSERT_EQ(*r2, 42U);
 
-  v2::Result<uint32_t> r3(v2::Error("foo"));
+  Result<uint32_t> r3(Error("foo"));
   r2 = r3;
   ASSERT_FALSE(r2);
   ASSERT_EQ(r2.GetErrorMessage(), "foo");
 }
 
 TEST(ResultTests, MoveAssignmentOperator) {
-  v2::Result<uint32_t> r(0U);
-  r = v2::Result<uint32_t>(42U);
+  Result<uint32_t> r(0U);
+  r = Result<uint32_t>(42U);
   ASSERT_TRUE(r);
   ASSERT_EQ(*r, 42U);
 
-  r = v2::Result<uint32_t>(v2::Error("foo"));
+  r = Result<uint32_t>(Error("foo"));
   ASSERT_FALSE(r);
   ASSERT_EQ(r.GetErrorMessage(), "foo");
 }
 
 // operator bool()
 TEST(ResultTests, BoolOperator) {
-  v2::Result<uint32_t> r1(42U);
+  Result<uint32_t> r1(42U);
   ASSERT_TRUE(r1);
   ASSERT_EQ(*r1, 42U);
 
-  v2::Result<uint32_t> r2(v2::Error("foo"));
+  Result<uint32_t> r2(Error("foo"));
   ASSERT_FALSE(r2);
   ASSERT_EQ(r2.GetErrorMessage(), "foo");
 }
 
 // operator*
 TEST(ResultTests, IndirectionOperator) {
-  const v2::Result<uint32_t> r1(42U);
+  const Result<uint32_t> r1(42U);
   ASSERT_TRUE(r1);
   ASSERT_EQ(*r1, 42U);
 
-  const v2::Result<Container> r2(Container{42U});
+  const Result<Container> r2(Container{42U});
   ASSERT_TRUE(r2);
   const Container& c = *r2;
   ASSERT_EQ(c.value, 42U);
 
-  v2::Result<Container> r3(Container{42U});
+  Result<Container> r3(Container{42U});
   ASSERT_TRUE(r3);
   ASSERT_EQ((*r3).value, 42U);
   (*r3).value = 0U;
@@ -153,11 +153,11 @@
 
 // operator->
 TEST(ResultTests, DereferenceOperator) {
-  const v2::Result<Container> r1(Container{42U});
+  const Result<Container> r1(Container{42U});
   ASSERT_TRUE(r1);
   ASSERT_EQ(r1->value, 42U);
 
-  v2::Result<Container> r2(Container{42U});
+  Result<Container> r2(Container{42U});
   ASSERT_TRUE(r2);
   ASSERT_EQ(r2->value, 42U);
   r2->value = 0U;
@@ -167,14 +167,14 @@
 // Tests: intended use of Result<T>
 
 TEST(ResultTests, ResultTraits) {
-  ASSERT_TRUE(std::is_move_constructible<v2::Result<uint32_t>>::value);
-  ASSERT_TRUE(std::is_move_assignable<v2::Result<uint32_t>>::value);
-  ASSERT_TRUE(std::is_copy_constructible<v2::Result<uint32_t>>::value);
-  ASSERT_TRUE(std::is_copy_assignable<v2::Result<uint32_t>>::value);
+  ASSERT_TRUE(std::is_move_constructible<Result<uint32_t>>::value);
+  ASSERT_TRUE(std::is_move_assignable<Result<uint32_t>>::value);
+  ASSERT_TRUE(std::is_copy_constructible<Result<uint32_t>>::value);
+  ASSERT_TRUE(std::is_copy_assignable<Result<uint32_t>>::value);
 }
 
 TEST(ResultTests, UnitTypeResult) {
-  v2::Result<v2::Unit> r(v2::Unit{});
+  Result<Unit> r(Unit{});
   ASSERT_TRUE(r);
 }
 
@@ -220,16 +220,16 @@
   ASSERT_FALSE(std::is_copy_assignable<RefCountContainer>::value);
 
   RefCountData rc{0, 0, 0, 0};
-  { v2::Result<RefCountContainer> r(RefCountContainer{rc}); }
+  { Result<RefCountContainer> r(RefCountContainer{rc}); }
   ASSERT_EQ(rc.ctor, 1);
   ASSERT_EQ(rc.copy_ctor, 1);
   ASSERT_EQ(rc.move, 0);
   ASSERT_EQ(rc.dtor, 2);
 }
 
-v2::Result<Container> CreateContainer(bool succeed) {
+Result<Container> CreateContainer(bool succeed) {
   if (!succeed) {
-    return v2::Error("foo");
+    return Error("foo");
   }
   return Container{42U};
 }
@@ -245,10 +245,10 @@
   ASSERT_EQ(r2.GetError().GetMessage(), "foo");
 }
 
-v2::Result<Container> FailToCreateContainer() {
+Result<Container> FailToCreateContainer() {
   auto container = CreateContainer(false);
   if (!container) {
-    return v2::Error(container.GetError(), "bar");
+    return Error(container.GetError(), "bar");
   }
   return container;
 }
@@ -264,9 +264,9 @@
   DISALLOW_COPY_AND_ASSIGN(NoCopyContainer);
 };
 
-v2::Result<std::unique_ptr<NoCopyContainer>> CreateNoCopyContainer(bool succeed) {
+Result<std::unique_ptr<NoCopyContainer>> CreateNoCopyContainer(bool succeed) {
   if (!succeed) {
-    return v2::Error("foo");
+    return Error("foo");
   }
   std::unique_ptr<NoCopyContainer> p(new NoCopyContainer{0U});
   p->value = 42U;