Re: questions about cv-qulifier for function.

[Jonathan Wakely <jwakely dot gcc at gmail dot com>]

On 1 December 2010 10:28, zhang qingshan wrote:
> Hi, team

This sort of question should be sent the mailing list gcc-help@gcc.gnu.org,
not the mailing list gcc@gcc.gnu.org.  gcc@gcc.gnu.org is for the
development of gcc itself.  Please take any future questions about using
gcc to gcc-help.  Thanks.

> Question 1:
>
> std(N3000=09-0190) 8.3.5/6 says that:

N3000 is not a standard, it's only a draft, and N3126 is the latest draft.

> A cv-qualifier-seq shall only be part of the function type for a
> non-static member function, the function type to which a pointer to
> member refers, or the top-level function type of a function typedef
> declaration.
>
> const void func();
>
> can be compiled successfully for GCC 4.5.0. However, I am confused about that:
>
> the const here doesn't belong to the three types which std allows. Why
> it is well-form?

The const is not part of the function type, it's part of the return
type, and is ignored.


> Question 2:
>
> std(N3000=09-0190) 8.3.2/1 says that:
>
> Cv-qualified references are ill-formed except when the cv-qualifiers
> are introduced through the use of a typedef (7.1.3) or of a template
> type argument (14.4), in which case the cv-qualifiers are ignored.
>
> int m = 3;
> const int &t = m;
>
> can be compiled successfully for GCC 4.5.0. But std says that
> cv-qualified references are not allowed to introduce except through
> the use of typedef or template type argument. In this case , it is
> allowed, why?

That is not a const-qualified reference, it's a reference to const int.

Please take any further questions to the gcc-help list or a C++ forum.

Thanks,

Jonathan