Disallow a specific function template instantiation

Question

I would like to define a template function but disallow instantiation with a particular type. Note that in general all types are allowed and the generic template works, I just w

Answer 1

If you don't want to rely on static_assert or make the code portable pre-C++0x, use this:

template
void func(){
    typedef char ERROR_in_the_matrix[std::is_same::value? -1 : 1];
}

int main(){
  func(); // no error
  func(); // error: negative subscript
}