[clang] Use std::nullopt instead of None in comments (NFC)

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

1 files changed, 9 insertions, 9 deletions

diff --git a/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp b/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
index 91dc252..cea4d91 100644
--- a/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
+++ b/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
@@ -56,8 +56,8 @@ void serializeArray(Object &Paren, StringRef Key, Optional<Array> Array) {
 ///   }
 /// \endcode
 ///
-/// \returns \c None if the version \p V is empty, or an \c Object containing
-/// the semantic version representation of \p V.
+/// \returns \c std::nullopt if the version \p V is empty, or an \c Object
+/// containing the semantic version representation of \p V.
 Optional<Object> serializeSemanticVersion(const VersionTuple &V) {
   if (V.empty())
     return std::nullopt;
@@ -142,8 +142,8 @@ Object serializeSourceRange(const PresumedLoc &BeginLoc,
 /// or deprecated, i.e. \c __attribute__((unavailable)) and \c
 /// __attribute__((deprecated)).
 ///
-/// \returns \c None if the symbol has default availability attributes, or
-/// an \c Array containing the formatted availability information.
+/// \returns \c std::nullopt if the symbol has default availability attributes,
+/// or an \c Array containing the formatted availability information.
 Optional<Array> serializeAvailability(const AvailabilitySet &Availabilities) {
   if (Availabilities.isDefault())
     return std::nullopt;
@@ -228,8 +228,8 @@ Object serializeIdentifier(const APIRecord &Record, Language Lang) {
 ///       ^~~~~~~~~~~~~~~~~~~~~~~'         Second line.
 /// \endcode
 ///
-/// \returns \c None if \p Comment is empty, or an \c Object containing the
-/// formatted lines.
+/// \returns \c std::nullopt if \p Comment is empty, or an \c Object containing
+/// the formatted lines.
 Optional<Object> serializeDocComment(const DocComment &Comment) {
   if (Comment.empty())
     return std::nullopt;
@@ -280,8 +280,8 @@ Optional<Object> serializeDocComment(const DocComment &Comment) {
 ///                    ]
 /// \endcode
 ///
-/// \returns \c None if \p DF is empty, or an \c Array containing the formatted
-/// declaration fragments array.
+/// \returns \c std::nullopt if \p DF is empty, or an \c Array containing the
+/// formatted declaration fragments array.
 Optional<Array> serializeDeclarationFragments(const DeclarationFragments &DF) {
   if (DF.getFragments().empty())
     return std::nullopt;
@@ -447,7 +447,7 @@ Optional<Object> serializeFunctionSignatureMixinImpl(const RecordTy &Record,
 ///   - The \c parameters array contains names and declaration fragments of the
 ///     parameters.
 ///
-/// \returns \c None if \p FS is empty, or an \c Object containing the
+/// \returns \c std::nullopt if \p FS is empty, or an \c Object containing the
 /// formatted function signature.
 template <typename RecordTy>
 void serializeFunctionSignatureMixin(Object &Paren, const RecordTy &Record) {