Having a C++ hell problem.

There's a namespace named "vendor", containing a class named "ClassName", containing an enum "EnumName", containing a value named "Success".

There's code that compiles on Windows with MSVC and on MacOS with Clang. But on Linux with GCC, it fails; if I say vendor::ClassName::Success it says "expected unqualified-id before numeric constant" on Success and if I say "vendor::ClassName::EnumName::Success" it says "expected unqualified-id before 'int'" on EnumName.

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