ceph/src/boost/libs/scope_exit/test/world_checkpoint_seq.cpp

   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/scope_exit.hpp>
  10 #include <boost/foreach.hpp>
  11 #include <boost/typeof/typeof.hpp>
  12 #include <boost/typeof/std/vector.hpp>
  13 #include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP()
  14 #include <boost/detail/lightweight_test.hpp>
  15 #include <vector>
  16 #include <sstream>
  17
  18 struct person {
  19     typedef unsigned int id_t;
  20     typedef unsigned int evolution_t;
  21
  22     id_t id;
  23     evolution_t evolution;
  24
  25     person(void) : id(0), evolution(0) {}
  26
  27     friend std::ostream& operator<<(std::ostream& o, person const& p) {
  28         return o << "person(" << p.id << ", " << p.evolution << ")";
  29     }
  30 };
  31 BOOST_TYPEOF_REGISTER_TYPE(person)
  32
  33 struct world {
  34     world(void) : next_id_(1) {}
  35     void add_person(person const& a_person);
  36
  37     friend std::ostream& operator<<(std::ostream& o, world const& w) {
  38         o << "world(" << w.next_id_ << ", {";
  39         BOOST_FOREACH(person const& p, w.persons_) {
  40             o << " " << p << ", ";
  41         }
  42         return o << "})";
  43     }
  44
  45 private:
  46     person::id_t next_id_;
  47     std::vector<person> persons_;
  48 };
  49 BOOST_TYPEOF_REGISTER_TYPE(world)
  50
  51 void world::add_person(person const& a_person) {
  52     persons_.push_back(a_person);
  53
  54     // This block must be no-throw.
  55     person& p = persons_.back();
  56     person::evolution_t checkpoint = p.evolution;
  57     BOOST_SCOPE_EXIT( (checkpoint) (&p) (&persons_) ) {
  58         if(checkpoint == p.evolution) persons_.pop_back();
  59     } BOOST_SCOPE_EXIT_END
  60
  61     // ...
  62
  63     checkpoint = ++p.evolution;
  64
  65     // Assign new identifier to the person.
  66     person::id_t const prev_id = p.id;
  67     p.id = next_id_++;
  68     BOOST_SCOPE_EXIT( (checkpoint) (&p) (&next_id_) (prev_id) ) {
  69         if(checkpoint == p.evolution) {
  70             next_id_ = p.id;
  71             p.id = prev_id;
  72         }
  73     } BOOST_SCOPE_EXIT_END
  74
  75     // ...
  76
  77     checkpoint = ++p.evolution;
  78 }
  79
  80 int main(void) {
  81     person adam, eva;
  82     std::ostringstream oss;
  83     oss << adam;
  84     BOOST_TEST(oss.str() == "person(0, 0)");
  85
  86     oss.str("");
  87     oss << eva;
  88     BOOST_TEST(oss.str() == "person(0, 0)");
  89
  90     world w;
  91     w.add_person(adam);
  92     w.add_person(eva);
  93     oss.str("");
  94     oss << w;
  95     BOOST_TEST(oss.str() == "world(3, { person(1, 2),  person(2, 2), })");
  96
  97     return boost::report_errors();
  98 }
  99