Template Point of Instantiation

Given:

template <T> 
int f(T a) {
    return sizeof(a);
} 

int main() {
   f<float>(4.0);
   return 0;
}

The template's point of instantiation is just before "int main".

A template declaration must be in scope at a template's point of instantiation.

Reference: http://publib.boulder.ibm.com/infocenter/compbgpl/v9v111/index.jsp?topic=/com.ibm.xlcpp9.bg.doc/language_ref/name_binding.htm