ceph/src/boost/libs/flyweight/test/test_assoc_cont_factory.cpp

   1 /* Boost.Flyweight test of assoc_container_factory.
   2  *
   3  * Copyright 2006-2018 Joaquin M Lopez Munoz.
   4  * Distributed under the Boost Software License, Version 1.0.
   5  * (See accompanying file LICENSE_1_0.txt or copy at
   6  * http://www.boost.org/LICENSE_1_0.txt)
   7  *
   8  * See http://www.boost.org/libs/flyweight for library home page.
   9  */
  10
  11 #include "test_assoc_cont_factory.hpp"
  12
  13 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
  14 #include <boost/flyweight/assoc_container_factory.hpp>
  15 #include <boost/flyweight/detail/is_placeholder_expr.hpp>
  16 #include <boost/flyweight/flyweight.hpp>
  17 #include <boost/flyweight/refcounted.hpp>
  18 #include <boost/flyweight/simple_locking.hpp>
  19 #include <boost/flyweight/static_holder.hpp>
  20 #include <boost/mpl/if.hpp>
  21 #include <functional>
  22 #include <set>
  23 #include "test_basic_template.hpp"
  24
  25 using namespace boost::flyweights;
  26
  27 struct reverse_set_specifier
  28 {
  29   template<typename Entry,typename Key>
  30   struct apply
  31   {
  32     typedef std::set<Entry,std::greater<Key> > type;
  33   };
  34 };
  35
  36 struct assoc_container_factory_flyweight_specifier1
  37 {
  38   template<typename T>
  39   struct apply
  40   {
  41     typedef flyweight<
  42       T,
  43       assoc_container_factory<reverse_set_specifier>
  44     > type;
  45   };
  46 };
  47
  48 /* flyweight<..., assoc_container_factory_class<std::set<...> >, ...> pulls
  49  * the type std::set<...> in as part of its associated ADL set and causes it
  50  * to be instantiated when doing any unqualified function call like, for
  51  * instance, comparing flyweights for equality, which can trigger a static
  52  * assertion in concept-checked STL implementations when std::set<...> is an
  53  * MPL placeholder expression. We avoid this mess with protected_set<...>.
  54  */
  55
  56 struct protected_set_empty_base{};
  57
  58 template<typename K,typename C,typename A>
  59 struct protected_set:
  60   boost::mpl::if_c<
  61     boost::flyweights::detail::is_placeholder_expression<
  62       protected_set<K,C,A>
  63     >::value,
  64     protected_set_empty_base,
  65     std::set<K,C,A>
  66   >::type
  67 {};
  68
  69 struct assoc_container_factory_flyweight_specifier2
  70 {
  71   template<typename T>
  72   struct apply
  73   {
  74     typedef flyweight<
  75       T,
  76       assoc_container_factory_class<
  77         protected_set<
  78           boost::mpl::_1,
  79           std::greater<boost::mpl::_2>,
  80           std::allocator<boost::mpl::_1>
  81         >
  82       >
  83     > type;
  84   };
  85 };
  86
  87 void test_assoc_container_factory()
  88 {
  89   test_basic_template<assoc_container_factory_flyweight_specifier1>();
  90   test_basic_template<assoc_container_factory_flyweight_specifier2>();
  91 }