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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 0 : 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 0 : element_type * const p = static_cast<element_type*>(ptr);
203 0 : 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
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