[Bug c++/47396] Link error when declare a constant reference to a class or struct static const member!

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47396

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-21 13:49:32 UTC ---
GCC bugzilla is not a place to learn C++, just read the standard, in particular
[class.static.data]/4:
"If a static data member is of const integral or const enumeration type, its
declaration in the class definition can specify a constant-initializer which
shall be an integral constant expression (5.19). In that case, the member can
appear in integral constant expressions within its scope. The member shall
still be defined in a namespace scope if it is used in the program and the
namespace scope definition shall not contain an initializer."

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-01-21 13:49:32 UTC ---
(In reply to comment #2)
> but like this:
> 
> struct test
> {
>     static const int i = 0;
> };
> 
> int main(void)
> {
>     const unsigned int &m = test::i;
> }
> 
> 
> no link errors!!!! why???

a temporary (of type unsigned) has to be created, and the reference binds to
the temporary, not to test::i

This is invalid, please don't reopen it