Once declared, templates can be used like any other function. Their use consists of naming the template and providing function arguments. The compiler can infer the template type arguments from the function argument types. For example, you can use the previously declared template as follows:
double twicedouble( double item )
{ return twice( item ); }If a template argument cannot be inferred from the function argument types, it must be supplied where the function is called. For example:
template<class T> T func(); // no function arguments int k = func<int>(); // template argument supplied explicitly