[libcxx-commits] [libcxx] [libc++] Fix initialization-order-fiasco with iostream.cpp constructors (PR #126995)

[Vitaly Buka via libcxx-commits]

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@@ -38,13 +38,20 @@ union stream_data {
 #define CHAR_MANGLING_wchar_t "_W"
 #define CHAR_MANGLING(CharT) CHAR_MANGLING_##CharT
 
+#ifdef _LIBCPP_COMPILER_CLANG_BASED
+#  define STRING_DATA_CONSTINIT constinit
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vitalybuka wrote:

can't figure out how to make GCC happy,
all the time:  error: ‘constinit’ variable ‘std::__1::cin’ does not have a constant initializer

https://github.com/llvm/llvm-project/pull/126995