302 struct ConstexprOptional {  struct
304   constexpr ConstexprOptional() : _has_value(false), _nothing() {  in ConstexprOptional()  argument
308   constexpr ConstexprOptional(const T& value)  // NOLINT(google-explicit-constructor)  in ConstexprOptional()  argument
345 operator==(const ConstexprOptional<T>& lhs, const ConstexprOptional<T>& rhs) {  argument
354 operator!=(const ConstexprOptional<T>& lhs, const ConstexprOptional<T>& rhs) {
359 inline std::ostream& operator<<(std::ostream& os, const ConstexprOptional<T>& val) {
371   constexpr operator ConstexprOptional<T>() const {  // NOLINT(google-explicit-constructor)
372     return ConstexprOptional<T>();
427 constexpr ConstexprOptional<ParseTypeDescriptorResult>
493       ConstexprOptional<ParseTypeDescriptorResult>
587 constexpr ConstexprOptional<JniSignatureDescriptor<kMaxSize>>
622         ConstexprOptional<ParseTypeDescriptorResult>  in ParseSignatureAsList()
632         ConstexprOptional<ParseTypeDescriptorResult>  in ParseSignatureAsList()
744   static constexpr ConstexprOptional<ReifiedJniTypeTrait>
803 constexpr ConstexprOptional<ReifiedJniTypeTrait>  in DEFINE_JNI_TYPE_TRAIT()
1113 constexpr ConstexprOptional<ReifiedJniSignature<kMaxSize>>
1155   ConstexprOptional<ReifiedJniTypeTrait> user_reified_opt =
1227   ConstexprOptional<ReifiedJniSignature<kReifiedMaxSize>>
1235   ConstexprOptional<JniSignatureDescriptor<kMaxSize>> user_jni_sig_desc_opt =
1282   static constexpr ConstexprOptional<JniSignatureDescriptor<kMaxSize>> FromFunctionType() {
1284     ConstexprOptional<ReifiedJniSignature<kReifiedMaxSize>>
1322     ConstexprOptional<JniSignatureDescriptor<kMaxSize>>
1361     ConstexprOptional<JniSignatureDescriptor<kMaxSize>>