commit 4382e44c42d2a1edf92a9ef11dbf34843025e64f
author Ryan Mitchell <rtmitchell@google.com> Wed Jul 14 12:53:01 2021 -0700
committer Ryan Mitchell <rtmitchell@google.com> Thu Jul 15 13:42:13 2021 -0700
tree f4b2855b1df909e526a298300ee55f79a65ccc79
parent 3947c9b56c2e79d76b6941fb5bdcdf25e359b0a4

Replace Maybe with std::optional

With c++17, std::optional provides the functionality that Maybe
provided.

Bug: 183215655
Test: aapt2_tests
Change-Id: I62bb9c2fa4985dc5217a6ed153df92b85ad9a034

tools/aapt2/xml/XmlPullParser.cpp

diff --git a/tools/aapt2/xml/XmlPullParser.cpp b/tools/aapt2/xml/XmlPullParser.cpp
index 182203d..bfa0749 100644
--- a/tools/aapt2/xml/XmlPullParser.cpp
+++ b/tools/aapt2/xml/XmlPullParser.cpp
@@ -17,7 +17,6 @@
 #include <iostream>
 #include <string>
 
-#include "util/Maybe.h"
 #include "util/Util.h"
 #include "xml/XmlPullParser.h"
 #include "xml/XmlUtil.h"
@@ -84,8 +83,7 @@
   // handling of references that use namespace aliases.
   if (next_event == Event::kStartNamespace ||
       next_event == Event::kEndNamespace) {
-    Maybe<ExtractedPackage> result =
-        ExtractPackageFromNamespace(namespace_uri());
+    std::optional<ExtractedPackage> result = ExtractPackageFromNamespace(namespace_uri());
     if (next_event == Event::kStartNamespace) {
       if (result) {
         package_aliases_.emplace_back(
@@ -142,7 +140,8 @@
   return event_queue_.front().data2;
 }
 
-Maybe<ExtractedPackage> XmlPullParser::TransformPackageAlias(const StringPiece& alias) const {
+std::optional<ExtractedPackage> XmlPullParser::TransformPackageAlias(
+    const StringPiece& alias) const {
   if (alias.empty()) {
     return ExtractedPackage{{}, false /*private*/};
   }
@@ -308,8 +307,7 @@
                                       parser->depth_ });
 }
 
-Maybe<StringPiece> FindAttribute(const XmlPullParser* parser,
-                                 const StringPiece& name) {
+std::optional<StringPiece> FindAttribute(const XmlPullParser* parser, const StringPiece& name) {
   auto iter = parser->FindAttribute("", name);
   if (iter != parser->end_attributes()) {
     return StringPiece(util::TrimWhitespace(iter->value));
@@ -317,8 +315,8 @@
   return {};
 }
 
-Maybe<StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser,
-                                         const StringPiece& name) {
+std::optional<StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser,
+                                                 const StringPiece& name) {
   auto iter = parser->FindAttribute("", name);
   if (iter != parser->end_attributes()) {
     StringPiece trimmed = util::TrimWhitespace(iter->value);