ceph/src/boost/boost/move/default_delete.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2014-2014. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/move for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef BOOST_MOVE_DEFAULT_DELETE_HPP_INCLUDED
  12 #define BOOST_MOVE_DEFAULT_DELETE_HPP_INCLUDED
  13
  14 #ifndef BOOST_CONFIG_HPP
  15 #  include <boost/config.hpp>
  16 #endif
  17 #
  18 #if defined(BOOST_HAS_PRAGMA_ONCE)
  19 #  pragma once
  20 #endif
  21
  22 #include <boost/move/detail/config_begin.hpp>
  23 #include <boost/move/detail/workaround.hpp>
  24 #include <boost/move/detail/unique_ptr_meta_utils.hpp>
  25 #include <boost/move/utility_core.hpp>
  26 #include <boost/static_assert.hpp>
  27
  28 #include <cstddef>   //For std::size_t,std::nullptr_t
  29
  30 //!\file
  31 //! Describes the default deleter (destruction policy) of <tt>unique_ptr</tt>: <tt>default_delete</tt>.
  32
  33 namespace boost{
  34 // @cond
  35 namespace move_upd {
  36
  37 namespace bmupmu = ::boost::move_upmu;
  38
  39 ////////////////////////////////////////
  40 ////        enable_def_del
  41 ////////////////////////////////////////
  42
  43 //compatible with a pointer type T*:
  44 //When either Y* is convertible to T*
  45 //Y is U[N] and T is U cv []
  46 template<class U, class T>
  47 struct def_del_compatible_cond
  48    : bmupmu::is_convertible<U*, T*>
  49 {};
  50
  51 template<class U, class T, std::size_t N>
  52 struct def_del_compatible_cond<U[N], T[]>
  53    : def_del_compatible_cond<U[], T[]>
  54 {};
  55
  56 template<class U, class T, class Type = bmupmu::nat>
  57 struct enable_def_del
  58    : bmupmu::enable_if_c<def_del_compatible_cond<U, T>::value, Type>
  59 {};
  60
  61 ////////////////////////////////////////
  62 ////        enable_defdel_call
  63 ////////////////////////////////////////
  64
  65 //When 2nd is T[N], 1st(*)[N] shall be convertible to T(*)[N];
  66 //When 2nd is T[],  1st(*)[] shall be convertible to T(*)[];
  67 //Otherwise, 1st* shall be convertible to 2nd*.
  68
  69 template<class U, class T, class Type = bmupmu::nat>
  70 struct enable_defdel_call
  71    : public enable_def_del<U, T, Type>
  72 {};
  73
  74 template<class U, class T, class Type>
  75 struct enable_defdel_call<U, T[], Type>
  76    : public enable_def_del<U[], T[], Type>
  77 {};
  78
  79 template<class U, class T, class Type, std::size_t N>
  80 struct enable_defdel_call<U, T[N], Type>
  81    : public enable_def_del<U[N], T[N], Type>
  82 {};
  83
  84 ////////////////////////////////////////
  85 ////     Some bool literal zero conversion utilities
  86 ////////////////////////////////////////
  87
  88 struct bool_conversion {int for_bool; int for_arg(); };
  89 typedef int bool_conversion::* explicit_bool_arg;
  90
  91 #if !defined(BOOST_NO_CXX11_NULLPTR) && !defined(BOOST_NO_CXX11_DECLTYPE)
  92    typedef decltype(nullptr) nullptr_type;
  93 #elif !defined(BOOST_NO_CXX11_NULLPTR)
  94    typedef std::nullptr_t nullptr_type;
  95 #else
  96    typedef int (bool_conversion::*nullptr_type)();
  97 #endif
  98
  99 template<bool B>
 100 struct is_array_del
 101 {};
 102
 103 template<class T>
 104 void call_delete(T *p, is_array_del<true>)
 105 {
 106    delete [] p;
 107 }
 108
 109 template<class T>
 110 void call_delete(T *p, is_array_del<false>)
 111 {
 112    delete p;
 113 }
 114
 115 }  //namespace move_upd {
 116 // @endcond
 117
 118 namespace movelib {
 119
 120 namespace bmupd = boost::move_upd;
 121 namespace bmupmu = ::boost::move_upmu;
 122
 123 //!The class template <tt>default_delete</tt> serves as the default deleter
 124 //!(destruction policy) for the class template <tt>unique_ptr</tt>.
 125 //!
 126 //! \tparam T The type to be deleted. It may be an incomplete type
 127 template <class T>
 128 struct default_delete
 129 {
 130    //! Default constructor.
 131    //!
 132    BOOST_CONSTEXPR default_delete()
 133    //Avoid "defaulted on its first declaration must not have an exception-specification" error for GCC 4.6
 134    #if !defined(BOOST_GCC) || (BOOST_GCC < 40600 && BOOST_GCC >= 40700) || defined(BOOST_MOVE_DOXYGEN_INVOKED)
 135    BOOST_NOEXCEPT
 136    #endif
 137    #if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) || defined(BOOST_MOVE_DOXYGEN_INVOKED)
 138    = default;
 139    #else
 140    {};
 141    #endif
 142
 143    #if defined(BOOST_MOVE_DOXYGEN_INVOKED)
 144    //! Trivial copy constructor
 145    //!
 146    default_delete(const default_delete&) BOOST_NOEXCEPT = default;
 147    //! Trivial assignment
 148    //!
 149    default_delete &operator=(const default_delete&) BOOST_NOEXCEPT = default;
 150    #else
 151    typedef typename bmupmu::remove_extent<T>::type element_type;
 152    #endif
 153
 154    //! <b>Effects</b>: Constructs a default_delete object from another <tt>default_delete<U></tt> object.
 155    //!
 156    //! <b>Remarks</b>: This constructor shall not participate in overload resolution unless:
 157    //!   - If T is not an array type and U* is implicitly convertible to T*.
 158    //!   - If T is an array type and U* is a more CV qualified pointer to remove_extent<T>::type.
 159    template <class U>
 160    default_delete(const default_delete<U>&
 161       BOOST_MOVE_DOCIGN(BOOST_MOVE_I typename bmupd::enable_def_del<U BOOST_MOVE_I T>::type* =0)
 162       ) BOOST_NOEXCEPT
 163    {
 164       //If T is not an array type, U derives from T
 165       //and T has no virtual destructor, then you have a problem
 166       BOOST_STATIC_ASSERT(( !::boost::move_upmu::missing_virtual_destructor<default_delete, U>::value ));
 167    }
 168
 169    //! <b>Effects</b>: Constructs a default_delete object from another <tt>default_delete<U></tt> object.
 170    //!
 171    //! <b>Remarks</b>: This constructor shall not participate in overload resolution unless:
 172    //!   - If T is not an array type and U* is implicitly convertible to T*.
 173    //!   - If T is an array type and U* is a more CV qualified pointer to remove_extent<T>::type.
 174    template <class U>
 175    BOOST_MOVE_DOC1ST(default_delete&,
 176       typename bmupd::enable_def_del<U BOOST_MOVE_I T BOOST_MOVE_I default_delete &>::type)
 177       operator=(const default_delete<U>&) BOOST_NOEXCEPT
 178    {
 179       //If T is not an array type, U derives from T
 180       //and T has no virtual destructor, then you have a problem
 181       BOOST_STATIC_ASSERT(( !::boost::move_upmu::missing_virtual_destructor<default_delete, U>::value ));
 182       return *this;
 183    }
 184
 185    //! <b>Effects</b>: if T is not an array type, calls <tt>delete</tt> on static_cast<T*>(ptr),
 186    //!   otherwise calls <tt>delete[]</tt> on static_cast<remove_extent<T>::type*>(ptr).
 187    //!
 188    //! <b>Remarks</b>: If U is an incomplete type, the program is ill-formed.
 189    //!   This operator shall not participate in overload resolution unless:
 190    //!      - T is not an array type and U* is convertible to T*, OR
 191    //!      - T is an array type, and remove_cv<U>::type is the same type as
 192    //!         remove_cv<remove_extent<T>::type>::type and U* is convertible to remove_extent<T>::type*.
 193    template <class U>
 194    BOOST_MOVE_DOC1ST(void, typename bmupd::enable_defdel_call<U BOOST_MOVE_I T BOOST_MOVE_I void>::type)
 195       operator()(U* ptr) const BOOST_NOEXCEPT
 196    {
 197       //U must be a complete type
 198       BOOST_STATIC_ASSERT(sizeof(U) > 0);
 199       //If T is not an array type, U derives from T
 200       //and T has no virtual destructor, then you have a problem
 201       BOOST_STATIC_ASSERT(( !::boost::move_upmu::missing_virtual_destructor<default_delete, U>::value ));
 202       element_type * const p = static_cast<element_type*>(ptr);
 203       move_upd::call_delete(p, move_upd::is_array_del<bmupmu::is_array<T>::value>());
 204    }
 205
 206    //! <b>Effects</b>: Same as <tt>(*this)(static_cast<element_type*>(nullptr))</tt>.
 207    //!
 208    void operator()(BOOST_MOVE_DOC0PTR(bmupd::nullptr_type)) const BOOST_NOEXCEPT
 209    {  BOOST_STATIC_ASSERT(sizeof(element_type) > 0);  }
 210 };
 211
 212 }  //namespace movelib {
 213 }  //namespace boost{
 214
 215 #include <boost/move/detail/config_end.hpp>
 216
 217 #endif   //#ifndef BOOST_MOVE_DEFAULT_DELETE_HPP_INCLUDED