delegate_arith_portable.cpp

An article on the implementation of a fast C++ delegate with many advanced features.

// FD.Delegate Library

// Copyright (C) 2001-2003 Douglas Gregor

// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

// For more information, see http://www.boost.org/

// Copyright (C) 2007 JaeWook Choi
// , modified from Boost.Function function_arith_portable.cpp


#include <fd/delegate.hpp>
#include <iostream>

float mul_ints(int x, int y) { return ((float)x) * y; }
struct int_div {
  float operator()(int x, int y) const { return ((float)x)/y; };
};
int main()
{
    fd::delegate2<float, int, int> f;
    f = int_div();
    std::cout << f(5, 3) << std::endl;
    if (f)
  std::cout << f(5, 3) << std::endl;
else
  std::cout << "f has no target, so it is unsafe to call" << std::endl;
    f = 0;
    f = &mul_ints;

    return 0;
}