This adjusts the workaround from D104731.
The issue lies in libstdc++'s classes, not GCC itself, and manifests
itself in the same way if building e.g. with clang while using
libstdc++ headers from GCC 7 (e.g. if building with Clang on Ubuntu 18.04,
while using the system default C++ library).
Therefore, change the condition to look for the version of libstdc++
instead of the compiler.
Differential Revision: https://reviews.llvm.org/D104779
return charLengthParamValue_;
}
constexpr std::optional<std::int64_t> knownLength() const {
-#if !__clang__ && __GNUC__ == 7
+#if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE == 7
if (knownLength_ < 0) {
return std::nullopt;
}
TypeCategory category_{TypeCategory::Derived}; // overridable default
int kind_{0};
const semantics::ParamValue *charLengthParamValue_{nullptr};
-#if !__clang__ && __GNUC__ == 7
+#if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE == 7
// GCC 7's optional<> lacks a constexpr operator=
std::int64_t knownLength_{-1};
#else