ceph/src/boost/libs/local_function/example/n2529_this.cpp

   1
   2 // Copyright (C) 2009-2012 Lorenzo Caminiti
   3 // Distributed under the Boost Software License, Version 1.0
   4 // (see accompanying file LICENSE_1_0.txt or a copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6 // Home at http://www.boost.org/libs/local_function
   7
   8 #include <boost/local_function.hpp>
   9 #include <boost/typeof/typeof.hpp>
  10 #include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP()
  11 #include <boost/detail/lightweight_test.hpp>
  12 #include <vector>
  13 #include <algorithm>
  14
  15 struct v;
  16 BOOST_TYPEOF_REGISTER_TYPE(v) // Register before `bind this_` below.
  17
  18 struct v {
  19     std::vector<int> nums;
  20
  21     v(const std::vector<int>& numbers): nums(numbers) {}
  22
  23     void change_sign_all(const std::vector<int>& indices) {
  24         void BOOST_LOCAL_FUNCTION(bind this_, int i) { // Bind object `this`.
  25             this_->nums.at(i) = -this_->nums.at(i);
  26         } BOOST_LOCAL_FUNCTION_NAME(complement)
  27
  28         std::for_each(indices.begin(), indices.end(), complement);
  29     }
  30 };
  31
  32 int main(void) {
  33     std::vector<int> n(3);
  34     n[0] = 1; n[1] = 2; n[2] = 3;
  35
  36     std::vector<int> i(2);
  37     i[0] = 0; i[1] = 2; // Will change n[0] and n[2] but not n[1].
  38
  39     v vn(n);
  40     vn.change_sign_all(i);
  41
  42     BOOST_TEST(vn.nums.at(0) == -1);
  43     BOOST_TEST(vn.nums.at(1) == 2);
  44     BOOST_TEST(vn.nums.at(2) == -3);
  45     return boost::report_errors();
  46 }
  47