1 | // Function library |
---|---|
2 | |
3 | // Copyright (C) 2001-2003 Douglas Gregor |
4 | |
5 | // Use, modification and distribution is subject to the Boost Software |
6 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
7 | // http://www.boost.org/LICENSE_1_0.txt) |
8 | |
9 | // For more information, see http://www.boost.org/ |
10 | |
11 | |
12 | #include <boost/function.hpp> |
13 | #include <iostream> |
14 | |
15 | |
16 | float mul_ints(int x, int y) { return ((float)x) * y; } |
17 | struct int_div { |
18 | float operator()(int x, int y) const { return ((float)x)/y; }; |
19 | }; |
20 | |
21 | int main() |
22 | { |
23 | boost::function<float (int x, int y)> f; |
24 | f = int_div(); |
25 | std::cout << f(5, 3) << std::endl; |
26 | if (f) |
27 | std::cout << f(5, 3) << std::endl; |
28 | else |
29 | std::cout << "f has no target, so it is unsafe to call"<< std::endl; |
30 | f = 0; |
31 | f = &mul_ints; |
32 | |
33 | return 0; |
34 | } |
35 |