ceph/src/boost/libs/signals/example/quotient_named.cpp

   1 // Boost.Signals library
   2
   3 // Copyright Douglas Gregor 2001-2003. Use, modification and
   4 // distribution is subject to the Boost Software License, Version
   5 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7
   8 // For more information, see http://www.boost.org
   9
  10 #include <iostream>
  11 #include <boost/signals/signal2.hpp>
  12 #include <cassert>
  13
  14 struct print_sum {
  15   void operator()(int x, int y) const { std::cout << x+y << std::endl; }
  16 };
  17
  18 struct print_product {
  19   void operator()(int x, int y) const { std::cout << x*y << std::endl; }
  20 };
  21
  22 struct print_difference {
  23   void operator()(int x, int y) const { std::cout << x-y << std::endl; }
  24 };
  25
  26 struct print_quotient {
  27   void operator()(int x, int y) const { std::cout << x/-y << std::endl; }
  28 };
  29
  30
  31 int main()
  32 {
  33   boost::signal2<void, int, int, boost::last_value<void>, std::string> sig;
  34
  35   sig.connect(print_sum());
  36   sig.connect(print_product());
  37
  38   sig(3, 5);
  39
  40   boost::signals::connection print_diff_con = sig.connect(print_difference());
  41
  42   // sig is still connected to print_diff_con
  43   assert(print_diff_con.connected());
  44
  45   sig(5, 3); // prints 8, 15, and 2
  46
  47   print_diff_con.disconnect(); // disconnect the print_difference slot
  48
  49   sig(5, 3); // now prints 8 and 15, but not the difference
  50
  51   assert(!print_diff_con.connected()); // not connected any more
  52
  53   {
  54     boost::signals::scoped_connection c = sig.connect(print_quotient());
  55     sig(5, 3); // prints 8, 15, and 1
  56   } // c falls out of scope, so sig and print_quotient are disconnected
  57
  58   sig(5, 3); // prints 8 and 15
  59
  60   sig.connect("quotient", print_quotient());
  61   sig(5, 3); // prints 8, 15, and 1
  62   sig.disconnect("quotient");
  63   sig(5, 3); // prints 8 and 15
  64
  65   return 0;
  66 }