how to query if(T==int) with template class

Question

When I\'m writing a function in a template class how can I find out what my T is?

e.g.

template 
ostream& operator << (os         


        

Answer 1

C++ templates don't work this way. The general idea of templates is express somethings which is common for a lot of different types. And in your case you should use template specialization.

template ostream& operator<< (ostream& out, const vector& v)
{
    // your general code for all type
}
// specialized template
template<> ostream& operator<< (ostream& out, const vector& vec)
{
    // your specific to iny type code goes here
}

Then C++ compiler will call this function when you use int type and general implementation for any other type

std::vector f(5, 5);
std::cout << f;