[Bug c++/68975] Request: Provide alternate keyword for decltype in C++03

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68975

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I see that clang supports __decltype (but not __decltype__, strangely)