Unfortunately, this very simple example, which we have been discussing for other reasons, regresses very badly vs tr1. Unfortunately the C++ front-end doesn't seem ready for a conforming result_of :( Can we prepare a reduced testcase for Jason?

Maybe he can already tell us whether an error message of the form: "sorry, unimplemented: unable to determine the declared type of expression ‘declval<X>()()’" points to an issue fixable any time soon...

Otherwise, I'm afraid that for 4.5.0 we have to revert consistently most C++0x work in <functional>.

///////////////

#include <functional>

struct X {
  typedef int result_type;
  int operator()() { return 0; }
  int operator()() const { return 1; }
};

const auto b = std::bind(X());

b(); // b is const, so must return 1