Can static_assert check if a type is a vector?

Question

Can static_assert check if a type is a vector? IE, an int would raise the assertion, whereas a vector<int> would not.
I'm thinking of something along the lines of:

static_assert(decltype(T) == std::vector, "Some error") 

Answer 1

Yes. Consider the following meta function:

#include <stdio.h> #include <vector>  template <class N> struct is_vector { static const int value = 0; };  template <class N, class A> struct is_vector<std::vector<N, A> > { static const int value = 1; };  int main() {    printf("is_vector<int>: %d\n", is_vector<int>::value);    printf("is_vector<vector<int> >: %d\n", is_vector<std::vector<int> >::value); } 

Simply use that as your expression in static_assert.

Answer 2

c++0x:

static_assert(std::is_same<T, std::vector<int>>::value, "Some Error");