[Bug c++/67777] New: unsigned wchar_t and signed wchar_t should cause compiler errors but do not.

[Bug c++/67777] New: unsigned wchar_t and signed wchar_t should cause compiler errors but do not.

[TrevorJamesHickey at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67777

            Bug ID: 67777
           Summary: unsigned wchar_t and signed wchar_t should cause
                    compiler errors but do not.
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: TrevorJamesHickey at gmail dot com
  Target Milestone: ---

Is the following program valid C++?

void f(unsigned wchar_t){}
int main(){}

It compiles without errors.   

The standard specifies that:  
"signed or unsigned can be combined with char, long, short, or int."

wchar_t is a distinct type, but the standard makes no mention of it being able
to be qualified with signed or unsigned.

"Type wchar_t shall have the same size, signedness, and alignment requirements
(3.11) as one of the other integral types, called its underlying type."  

Why can we add signed/unsigned qualifiers to wchar_t?  
Is this by design?  Can I get a warning about this?

[Bug c++/67777] unsigned wchar_t and signed wchar_t should cause compiler errors but do not.

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67777

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
         Resolution|---                         |FIXED
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=84701
             Status|UNCONFIRMED                 |RESOLVED
   Target Milestone|---                         |9.0

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This changed in GCC9+ to always reject.  Most likely by the patch which fixed
PR 84701.

[Bug c++/67777] unsigned wchar_t and signed wchar_t should cause compiler errors but do not.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67777

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Yes, it was fixed by r259780