[libc++] Mark string operator+ _LIBCPP_FUNC_VIS
It has an extern template instantiation declaration in the headers and a
corresponding instantiation definition in the library, so we must mark
it with _LIBCPP_FUNC_VIS to make it available outside the library.
This doesn't cause any ABI changes as-is since we don't build libc++
with hidden visibility (so the function is exported anyway). It's needed
for building libc++ with hidden visibility, however.
Clarify the Windows behavior for extern function templates while I'm
here, since this exercises that behavior.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@307966 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed