#include <utility>

struct Test{
int i;
Test(int a): i(a){}

bool operator==(const Test & aTest) const{
return i == aTest.i;
}

};


namespace std{
//namespace rel_ops{

template <class _Tp>
inline bool _STLP_CALL operator!=(const _Tp& __x, const _Tp& __y) {
return !(__x == __y);
}

//}
}

using namespace std;//::rel_ops;  //auto generate operator !=, <= , > ,
>=std::rel_ops;  //auto generate operator !=, <= , > , >=

int main( ){

Test a(0), b(3);

a == b; //ok
a != b;

return 0;
}


it seems dmc did not search template in imported namespace !