ceph/src/boost/boost/smart_ptr/detail/local_counted_base.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_LOCAL_COUNTED_BASE_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_LOCAL_COUNTED_BASE_HPP_INCLUDED
   3
   4 // MS compatible compilers support #pragma once
   5
   6 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
   7 # pragma once
   8 #endif
   9
  10 //  detail/local_counted_base.hpp
  11 //
  12 //  Copyright 2017 Peter Dimov
  13 //
  14 //  Distributed under the Boost Software License, Version 1.0. (See
  15 //  accompanying file LICENSE_1_0.txt or copy at
  16 //  http://www.boost.org/LICENSE_1_0.txt)
  17 //
  18 //  See http://www.boost.org/libs/smart_ptr/ for documentation.
  19
  20 #include <boost/smart_ptr/detail/shared_count.hpp>
  21 #include <boost/config.hpp>
  22 #include <utility>
  23
  24 namespace boost
  25 {
  26
  27 namespace detail
  28 {
  29
  30 class local_counted_base
  31 {
  32 private:
  33
  34     local_counted_base & operator= ( local_counted_base const & );
  35
  36 private:
  37
  38     // not 'int' or 'unsigned' to avoid aliasing and enable optimizations
  39     enum count_type { min_ = 0, initial_ = 1, max_ = 2147483647 };
  40
  41     count_type local_use_count_;
  42
  43 public:
  44
  45     BOOST_CONSTEXPR local_counted_base() BOOST_SP_NOEXCEPT: local_use_count_( initial_ )
  46     {
  47     }
  48
  49     BOOST_CONSTEXPR local_counted_base( local_counted_base const & ) BOOST_SP_NOEXCEPT: local_use_count_( initial_ )
  50     {
  51     }
  52
  53     virtual ~local_counted_base() /*BOOST_SP_NOEXCEPT*/
  54     {
  55     }
  56
  57     virtual void local_cb_destroy() BOOST_SP_NOEXCEPT = 0;
  58
  59     virtual boost::detail::shared_count local_cb_get_shared_count() const BOOST_SP_NOEXCEPT = 0;
  60
  61     void add_ref() BOOST_SP_NOEXCEPT
  62     {
  63 #if !defined(__NVCC__)
  64 #if defined( __has_builtin )
  65 # if __has_builtin( __builtin_assume )
  66
  67         __builtin_assume( local_use_count_ >= 1 );
  68
  69 # endif
  70 #endif
  71 #endif
  72
  73         local_use_count_ = static_cast<count_type>( local_use_count_ + 1 );
  74     }
  75
  76     void release() BOOST_SP_NOEXCEPT
  77     {
  78         local_use_count_ = static_cast<count_type>( local_use_count_ - 1 );
  79
  80         if( local_use_count_ == 0 )
  81         {
  82             local_cb_destroy();
  83         }
  84     }
  85
  86     long local_use_count() const BOOST_SP_NOEXCEPT
  87     {
  88         return local_use_count_;
  89     }
  90 };
  91
  92 class local_counted_impl: public local_counted_base
  93 {
  94 private:
  95
  96     local_counted_impl( local_counted_impl const & );
  97
  98 private:
  99
 100     shared_count pn_;
 101
 102 public:
 103
 104     explicit local_counted_impl( shared_count const& pn ): pn_( pn )
 105     {
 106     }
 107
 108 #if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
 109
 110     explicit local_counted_impl( shared_count && pn ): pn_( std::move(pn) )
 111     {
 112     }
 113
 114 #endif
 115
 116     virtual void local_cb_destroy() BOOST_SP_NOEXCEPT
 117     {
 118         delete this;
 119     }
 120
 121     virtual boost::detail::shared_count local_cb_get_shared_count() const BOOST_SP_NOEXCEPT
 122     {
 123         return pn_;
 124     }
 125 };
 126
 127 class local_counted_impl_em: public local_counted_base
 128 {
 129 public:
 130
 131     shared_count pn_;
 132
 133     virtual void local_cb_destroy() BOOST_SP_NOEXCEPT
 134     {
 135         shared_count().swap( pn_ );
 136     }
 137
 138     virtual boost::detail::shared_count local_cb_get_shared_count() const BOOST_SP_NOEXCEPT
 139     {
 140         return pn_;
 141     }
 142 };
 143
 144 } // namespace detail
 145
 146 } // namespace boost
 147
 148 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_LOCAL_COUNTED_BASE_HPP_INCLUDED