Re: [boost] sizeof_array?

From: Kostya Altukhov (kostya_at_[hidden])
Date: 2002-06-24 09:09:12

Daniel Frey wrote:

>This allows using sizeof_array safely, as it doesn't compile for
>non-arrays. The only potential drawback I found is, that it's use is a
>bit more complicated for static evaluation and sometimes, you need
>typeof (hopefully in the next standard!?).
>
You can use the following trick:

   template<typename T, size_t N>
   const char (&sizer(const T (&)[N])) [N];

then the usage is:

   double x[] = { 1, 2, 3, 4, 5, 6 };
   typedef int[42] X;
   enum {
      V1 = sizeof(sizer(X)),
      V2 = sizeof(sizer(x))
   }

No typeof necessary, and doesn't compile for non-arrays.

Best regards,
Kostya