[Bug c++/56643] Failure to match noexcept specifier of friend template function in template class

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56643

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
This is fixed in trunk, I'm adding the testcase and closing the bug.