[libcxx-commits] [libcxx] [libc++] Fix ungetc failing after xsgetn (PR #210951)

[Louis Dionne via libcxx-commits]

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@@ -15,6 +15,21 @@
 #include <streambuf>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
+_LIBCPP_BEGIN_EXPLICIT_ABI_ANNOTATIONS
+
+template <class _CharT, class _Traits>
+bool basic_filebuf<_CharT, _Traits>::__read_mode() {
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ldionne wrote:

Let's add a comment explaining why this is still provided even though it's unused.

https://github.com/llvm/llvm-project/pull/210951