[Bug c++/102350] __builtin_source_location not available in earlier language modes

[pdimov at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102350

--- Comment #18 from Peter Dimov <pdimov at gmail dot com> ---
I would use it like this: https://godbolt.org/z/1eqEx6678

#include <source_location>

struct error_category
{
};

error_category const& system_category();

struct error_code
{
    error_code( int v, error_category const& cat, void const* loc =
__builtin_source_location() );
};

int main()
{
    error_code ec( 5, system_category() );
}

provided, of course, I have some not-undefined way to interpret its result.