get_result_type

A nested typedef named type, that is the return type of the function type in result_of's template parameter.

typedef /* implementation details */ type; ();

This can be used to specify the operator within function objects that have multiple signatures. result_of is typically used in template programming (as opposed to just determining the return type).

namespace std::tr1{
#include <functional>
#include <iostream>
#include <typeinfo>

typedef double (*FP)(int, short);
int main()
{
   std::cout << typeid(std::tr1::result_of<FP>::type).name() << '\n';
   std::cout << typeid(result_of<less<int>(int, int)>::type).name() 
   << '\n'
};
}

result

  double
  bool

Class type_info