// Boost.Signals library // Copyright Douglas Gregor 2001-2003. 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 #include <algorithm> #include <iostream> #include <boost/signals/signal2.hpp> template<typename T> struct maximum { typedef T result_type; template<typename InputIterator> T operator()(InputIterator first, InputIterator last) const { if (first == last) throw std::runtime_error("Cannot compute maximum of zero elements!"); return *std::max_element(first, last); } }; int main() { boost::signal2<int, int, int, maximum<int> > sig_max; sig_max.connect(std::plus<int>()); sig_max.connect(std::multiplies<int>()); sig_max.connect(std::minus<int>()); sig_max.connect(std::divides<int>()); std::cout << sig_max(5, 3) << std::endl; // prints 15 return 0; }