#include <iostream>
#include <boost/concept_check.hpp>
#include <boost/concept/requires.hpp>


template <typename T>
struct foo
{ };


template <class X>
struct DummyConcept
{
    typedef typename X::something something;
    
    BOOST_CONCEPT_USAGE(DummyConcept){
    }
};


template<typename T>
 BOOST_CONCEPT_REQUIRES(
     ((DummyConcept<T>)),
     (void)) 
func(T&)
{ std::cout << "first overload" << std::endl; }

template<typename T>
 void func(foo<T>)
 { std::cout << "second overload" << std::endl; }
 

int main()
{
    func(foo<int>());
    return 0;
}