Re: [Mingw-users] [OT] static consts in template classes with MSVC?

[Greg C. <chi...@mi...>]

Nicolas Weber wrote:
> 
> template<class Num>
> class Matrix44
> {
>   public:
>    Matrix44(Num _00, Num _01, Num _02, Num _03,
>             ..., Num _33);

Given the static data member definitions below, you
probably intend sixteen arguments here.

>    static const Matrix44<Num> IDENTITY;
>    static const Matrix44<Num> ZERO;
> 
>   private:
>    Num m[4][4];
> };
> 
> Now I want to put the IDENTITY and ZERO definitions outside the class,
> what is the right syntax?
> 
> template <class Num>
> const Matrix44<Num> Matrix44<Num>::IDENTITY(1, 0, 0, 0, 0, 1, 0, 0, 0,
> 0, 1, 0, 0, 0, 0, 1);
> 
> works with gcc 3.3, but it does not with MSVC (MSVC interprets the above
> as a function declaration). Now, is this a problem with MSVCs compiler
> or is the above syntax wrong?

Try it here
  http://www.comeaucomputing.com/tryitout/
If gcc and comeau agree, then one would suspect that
msvc is incorrect, though that's not conclusive. But
if the statement above were a declaration of a member
function, wouldn't it have to occur inside the class?
Ambiguities between declarations and statements are
generally resolved as declarations, but I don't see
an ambiguity here.

If you follow the example in 14.5.1.3, then it's more
likely that all compilers will agree. I guess it'd
look something like

  template <class Num>
  const Matrix44<Num> Matrix44<Num>::ZERO = Matrix44<Num>
    (1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);