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

TypeID is never a good idea. It relies on RTTI. By the way here is your answer :http://www.parashift.com/c++-faq-lite/templates.html#faq-35.7

Answer 2

One more solution is:

if(std::is_same<T, int>::value)
     //It is int
if (std::is_same<T, double>::value)
     //It is double
if (std::is_same<T, long double>::value)
     //It is long double

Answer 3

This way.

ostream & operator << (ostream &out, Vector<int> const & vec)
{
    // ...
}

The compiler will choose this function over the function template if you pass Vector<int>.

Edit: I found this article, which attempts to explain why to prefer overloading to template specialization.