[Bug c++/20547] undefined reference to "static const" fields of classes

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-19 14:34 -------
(In reply to comment #5)
> I understand what you mean.
> But why the following codes works:
> 
> #include <iostream>
> #include <vector>
> 
> struct T
> {
>   static char const a = 3;
> };
> 
> std::vector<char> ddd;
> 
> int
> main()
> {
>   ddd.push_back(static_cast<char>(T::a)); // <========= here
> 
>   std::cerr << ddd.front() << std::endl;
> 
>   return 0;
> }
> 
> and if I pass an constant to a function which takes its address,
Because you changed an lvalue to a rvalue.

> then why the folloing codes doesn't produce errors?

Because constants are rvalues so there is going to be a temporary variable made for you.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20547