[Bug c++/70529] Unhelpful diagnostic for hex float literals, inconsistent parsing

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70529

--- Comment #9 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Thu, 7 Apr 2016, manu at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70529
> 
> --- Comment #8 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
> (In reply to Axel Naumann from comment #2)
> > You asked for it, so here is my wish list:
> > - for C++ < 1z, do not support hexfloats, neither with "unsigned" not
> > negative exponents.
> 
> Since "unsigned" exponents are supported by standard C++11, g++ has to support
> them.

They aren't supported in the sense of being valid floating-literals.  
It's simply the case that if the 'p' or 'P' is followed by a digit, rather 
than by '+' or '-', then it forms part of the pp-number whatever standard 
version is in use (and so none of the lexical complications arise that 
occur in the p+ / p- / P+ / P- cases, so handling p<digit> as an extension 
is easy).