[Bug c++/102804] template matching fails w/ false ambiguity on ternary expressions with enums class defined with unsigned typdef

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102804

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
unsigned int32_t is invalid. You cannot use unsigned (or short or long) with a
typedef, only with 'int'.

GCC was changed to diagnose that fairly recently, which is probably why the
behaviour changed since GCC 7.