#include <boost/type_traits/is_function.hpp>

struct CallerConst
  {
  void Call() const
    {
    }
  };

struct CallerNonConst
  {
  void Call()
    {
    }
  };

struct FunctorNonConst
  {
  void operator()()
    {
    }
  };

struct FunctorConst
  {
  void operator()() const
    {
    }
  };

void Function()
  {
  }

int main()
  {
  auto val1 = boost::is_function<void()>::value;
  auto val2 = boost::is_function<decltype(Function)>::value;
  auto val3 = boost::is_function<decltype(CallerConst().Call())>::value;
  auto val4 = boost::is_function<decltype(CallerNonConst().Call())>::value;
  auto val5 = boost::is_function<decltype(FunctorNonConst().operator())>::value;
  auto val6 = boost::is_function<decltype(FunctorConst().operator())>::value; // VC++ compile error if any of val1, val2, val5 is present

  return 0;
  }