[patch] Implement std::experimental::source_location (sort of)

[Martin Sebor]

On 11/13/2015 05:56 AM, Jonathan Wakely wrote:
> This is a non-conforming implementation of
> https://rawgit.com/cplusplus/fundamentals-ts/v2/fundamentals-ts.html#reflection.src_loc
>
>
> It doesn't provide any column numbers, and fails to meet the
> requirement that using current() in a NSDMI will refer to the location
> of the constructor ... but maybe it's good enough until we get the
> necessary front-end support. It is experimental, after all.
>
> Thoughts?

Lars (CC'd) mentioned he was interested in implementing the front
end support (http://gcc.gnu.org/PR66561).

Martin