1 2 // Copyright (C) 2006-2009, 2012 Alexander Nasonov 3 // Copyright (C) 2012 Lorenzo Caminiti 4 // Distributed under the Boost Software License, Version 1.0 5 // (see accompanying file LICENSE_1_0.txt or a copy at 6 // http://www.boost.org/LICENSE_1_0.txt) 7 // Home at http://www.boost.org/libs/scope_exit 8 9 #include <boost/config.hpp> 10 #ifdef BOOST_NO_CXX11_VARIADIC_MACROS 11 # error "variadic macros required" 12 #else 13 14 #include <boost/scope_exit.hpp> 15 #include <boost/typeof/typeof.hpp> 16 #include <boost/typeof/std/vector.hpp> 17 #include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP() 18 #include <boost/detail/lightweight_test.hpp> 19 #include <vector> 20 21 struct person {}; 22 BOOST_TYPEOF_REGISTER_TYPE(person) 23 24 struct world { 25 void add_person(person const& a_person); populationworld26 size_t population(void) const { return persons_.size(); } 27 28 private: 29 std::vector<person> persons_; 30 }; BOOST_TYPEOF_REGISTER_TYPE(world)31BOOST_TYPEOF_REGISTER_TYPE(world) 32 33 //[world 34 void world::add_person(person const& a_person) { 35 bool commit = false; 36 37 persons_.push_back(a_person); // (1) direct action 38 // Following block is executed when the enclosing scope exits. 39 BOOST_SCOPE_EXIT(&commit, &persons_) { 40 if(!commit) persons_.pop_back(); // (2) rollback action 41 } BOOST_SCOPE_EXIT_END 42 43 // ... // (3) other operations 44 45 commit = true; // (4) disable rollback actions 46 } 47 //] 48 main(void)49int main(void) { 50 world w; 51 person p; 52 w.add_person(p); 53 BOOST_TEST(w.population() == 1); 54 return boost::report_errors(); 55 } 56 57 #endif // variadic macros 58 59