ceph/src/boost/boost/core/noinit_adaptor.hpp

   1 /*
   2 Copyright 2019 Glen Joseph Fernandes
   3 (glenjofe@gmail.com)
   4
   5 Distributed under the Boost Software License, Version 1.0.
   6 (http://www.boost.org/LICENSE_1_0.txt)
   7 */
   8 #ifndef BOOST_CORE_NOINIT_ADAPTOR_HPP
   9 #define BOOST_CORE_NOINIT_ADAPTOR_HPP
  10
  11 #include <boost/config.hpp>
  12 #if !defined(BOOST_NO_CXX11_ALLOCATOR)
  13 #include <memory>
  14 #endif
  15 #include <new>
  16 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  17 #include <utility>
  18 #endif
  19
  20 namespace boost {
  21
  22 template<class A>
  23 struct noinit_adaptor
  24     : A {
  25     template<class U>
  26     struct rebind {
  27 #if !defined(BOOST_NO_CXX11_ALLOCATOR)
  28         typedef noinit_adaptor<typename std::allocator_traits<A>::template
  29             rebind_alloc<U> > other;
  30 #else
  31         typedef noinit_adaptor<typename A::template rebind<U>::other> other;
  32 #endif
  33     };
  34
  35     noinit_adaptor()
  36         : A() { }
  37
  38 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  39     template<class U>
  40     noinit_adaptor(U&& u) BOOST_NOEXCEPT
  41         : A(std::forward<U>(u)) { }
  42 #else
  43     template<class U>
  44     noinit_adaptor(const U& u) BOOST_NOEXCEPT
  45         : A(u) { }
  46 #endif
  47
  48     template<class U>
  49     noinit_adaptor(const noinit_adaptor<U>& u) BOOST_NOEXCEPT
  50         : A(static_cast<const U&>(u)) { }
  51
  52     template<class U>
  53     void construct(U* p) {
  54         ::new((void*)p) U;
  55     }
  56
  57 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  58 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
  59     template<class U, class V, class... Args>
  60     void construct(U* p, V&& v, Args&&... args) {
  61         ::new((void*)p) U(std::forward<V>(v), std::forward<Args>(args)...);
  62     }
  63 #else
  64     template<class U, class V>
  65     void construct(U* p, V&& v) {
  66         ::new((void*)p) U(std::forward<V>(v));
  67     }
  68 #endif
  69 #else
  70     template<class U, class V>
  71     void construct(U* p, const V& v) {
  72         ::new((void*)p) U(v);
  73     }
  74
  75     template<class U, class V>
  76     void construct(U* p, V& v) {
  77         ::new((void*)p) U(v);
  78     }
  79 #endif
  80
  81     template<class U>
  82     void destroy(U* p) {
  83         p->~U();
  84     }
  85 };
  86
  87 template<class T, class U>
  88 inline bool
  89 operator==(const noinit_adaptor<T>& lhs,
  90     const noinit_adaptor<U>& rhs) BOOST_NOEXCEPT
  91 {
  92     return static_cast<const T&>(lhs) == static_cast<const U&>(rhs);
  93 }
  94
  95 template<class T, class U>
  96 inline bool
  97 operator!=(const noinit_adaptor<T>& lhs,
  98     const noinit_adaptor<U>& rhs) BOOST_NOEXCEPT
  99 {
 100     return !(lhs == rhs);
 101 }
 102
 103 template<class A>
 104 inline noinit_adaptor<A>
 105 noinit_adapt(const A& a) BOOST_NOEXCEPT
 106 {
 107     return noinit_adaptor<A>(a);
 108 }
 109
 110 } /* boost */
 111
 112 #endif