Replace Maybe with std::optional

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

Bug: 183215655
Test: aapt2_tests
Change-Id: I62bb9c2fa4985dc5217a6ed153df92b85ad9a034

2 files changed, 10 insertions, 11 deletions

diff --git a/tools/aapt2/process/SymbolTable.cpp b/tools/aapt2/process/SymbolTable.cpp
index d385267fe5ed..2d58cbfb3dbe 100644
--- a/tools/aapt2/process/SymbolTable.cpp
+++ b/tools/aapt2/process/SymbolTable.cpp
@@ -75,8 +75,8 @@ const SymbolTable::Symbol* SymbolTable::FindByName(const ResourceName& name) {
 
   // Fill in the package name if necessary.
   // If there is no package in `name`, we will need to copy the ResourceName
-  // and store it somewhere; we use the Maybe<> class to reserve storage.
-  Maybe<ResourceName> name_with_package_impl;
+  // and store it somewhere; we use the std::optional<> class to reserve storage.
+  std::optional<ResourceName> name_with_package_impl;
   if (name.package.empty()) {
     name_with_package_impl = ResourceName(mangler_->GetTargetPackageName(), name.type, name.entry);
     name_with_package = &name_with_package_impl.value();
@@ -88,9 +88,9 @@ const SymbolTable::Symbol* SymbolTable::FindByName(const ResourceName& name) {
   }
 
   // The name was not found in the cache. Mangle it (if necessary) and find it in our sources.
-  // Again, here we use a Maybe<> object to reserve storage if we need to mangle.
+  // Again, here we use a std::optional<> object to reserve storage if we need to mangle.
   const ResourceName* mangled_name = name_with_package;
-  Maybe<ResourceName> mangled_name_impl;
+  std::optional<ResourceName> mangled_name_impl;
   if (mangler_->ShouldMangle(name_with_package->package)) {
     mangled_name_impl = mangler_->MangleName(*name_with_package);
     mangled_name = &mangled_name_impl.value();
@@ -183,7 +183,7 @@ std::unique_ptr<SymbolTable::Symbol> DefaultSymbolTableDelegate::FindById(
 
 std::unique_ptr<SymbolTable::Symbol> ResourceTableSymbolSource::FindByName(
     const ResourceName& name) {
-  Maybe<ResourceTable::SearchResult> result = table_->FindResource(name);
+  std::optional<ResourceTable::SearchResult> result = table_->FindResource(name);
   if (!result) {
     if (name.type == ResourceType::kAttr) {
       // Recurse and try looking up a private attribute.
@@ -306,7 +306,7 @@ static std::unique_ptr<SymbolTable::Symbol> LookupAttributeInTable(
         return nullptr;
       }
 
-      Maybe<ResourceName> parsed_name = ResourceUtils::ToResourceName(*name);
+      std::optional<ResourceName> parsed_name = ResourceUtils::ToResourceName(*name);
       if (!parsed_name) {
         return nullptr;
       }
@@ -382,8 +382,7 @@ std::unique_ptr<SymbolTable::Symbol> AssetManagerSymbolSource::FindByName(
   return {};
 }
 
-static Maybe<ResourceName> GetResourceName(android::AssetManager2& am,
-                                           ResourceId id) {
+static std::optional<ResourceName> GetResourceName(android::AssetManager2& am, ResourceId id) {
   auto name = am.GetResourceName(id.id);
   if (!name.has_value()) {
     return {};
@@ -402,7 +401,7 @@ std::unique_ptr<SymbolTable::Symbol> AssetManagerSymbolSource::FindById(
     return {};
   }
 
-  Maybe<ResourceName> maybe_name = GetResourceName(asset_manager_, id);
+  std::optional<ResourceName> maybe_name = GetResourceName(asset_manager_, id);
   if (!maybe_name) {
     return {};
   }
diff --git a/tools/aapt2/process/SymbolTable.h b/tools/aapt2/process/SymbolTable.h
index 06eaf63ad442..65ae7beadc07 100644
--- a/tools/aapt2/process/SymbolTable.h
+++ b/tools/aapt2/process/SymbolTable.h
@@ -56,7 +56,7 @@ class SymbolTable {
   struct Symbol {
     Symbol() = default;
 
-    explicit Symbol(const Maybe<ResourceId>& i, const std::shared_ptr<Attribute>& attr = {},
+    explicit Symbol(const std::optional<ResourceId>& i, const std::shared_ptr<Attribute>& attr = {},
                     bool pub = false)
         : id(i), attribute(attr), is_public(pub) {
     }
@@ -66,7 +66,7 @@ class SymbolTable {
     Symbol& operator=(const Symbol&) = default;
     Symbol& operator=(Symbol&&) = default;
 
-    Maybe<ResourceId> id;
+    std::optional<ResourceId> id;
     std::shared_ptr<Attribute> attribute;
     bool is_public = false;
     bool is_dynamic = false;