1 | /* Copyright 2003-2013 Joaquin M Lopez Munoz. |
2 | * Distributed under the Boost Software License, Version 1.0. |
3 | * (See accompanying file LICENSE_1_0.txt or copy at |
4 | * http://www.boost.org/LICENSE_1_0.txt) |
5 | * |
6 | * See Boost website at http://www.boost.org/ |
7 | */ |
8 | |
9 | #ifndef BOOST_DETAIL_ALLOCATOR_UTILITIES_HPP |
10 | #define BOOST_DETAIL_ALLOCATOR_UTILITIES_HPP |
11 | |
12 | #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ |
13 | #include <boost/detail/workaround.hpp> |
14 | #include <boost/mpl/eval_if.hpp> |
15 | #include <boost/type_traits/is_same.hpp> |
16 | #include <cstddef> |
17 | #include <memory> |
18 | #include <new> |
19 | |
20 | namespace boost{ |
21 | |
22 | namespace detail{ |
23 | |
24 | /* Allocator adaption layer. Some stdlibs provide allocators without rebind |
25 | * and template ctors. These facilities are simulated with the external |
26 | * template class rebind_to and the aid of partial_std_allocator_wrapper. |
27 | */ |
28 | |
29 | namespace allocator{ |
30 | |
31 | /* partial_std_allocator_wrapper inherits the functionality of a std |
32 | * allocator while providing a templatized ctor and other bits missing |
33 | * in some stdlib implementation or another. |
34 | */ |
35 | |
36 | template<typename Type> |
37 | class partial_std_allocator_wrapper:public std::allocator<Type> |
38 | { |
39 | public: |
40 | /* Oddly enough, STLport does not define std::allocator<void>::value_type |
41 | * when configured to work without partial template specialization. |
42 | * No harm in supplying the definition here unconditionally. |
43 | */ |
44 | |
45 | typedef Type value_type; |
46 | |
47 | partial_std_allocator_wrapper(){}; |
48 | |
49 | template<typename Other> |
50 | partial_std_allocator_wrapper(const partial_std_allocator_wrapper<Other>&){} |
51 | |
52 | partial_std_allocator_wrapper(const std::allocator<Type>& x): |
53 | std::allocator<Type>(x) |
54 | { |
55 | }; |
56 | |
57 | #if defined(BOOST_DINKUMWARE_STDLIB) |
58 | /* Dinkumware guys didn't provide a means to call allocate() without |
59 | * supplying a hint, in disagreement with the standard. |
60 | */ |
61 | |
62 | Type* allocate(std::size_t n,const void* hint=0) |
63 | { |
64 | std::allocator<Type>& a=*this; |
65 | return a.allocate(n,hint); |
66 | } |
67 | #endif |
68 | |
69 | }; |
70 | |
71 | /* Detects whether a given allocator belongs to a defective stdlib not |
72 | * having the required member templates. |
73 | * Note that it does not suffice to check the Boost.Config stdlib |
74 | * macros, as the user might have passed a custom, compliant allocator. |
75 | * The checks also considers partial_std_allocator_wrapper to be |
76 | * a standard defective allocator. |
77 | */ |
78 | |
79 | #if defined(BOOST_NO_STD_ALLOCATOR)&&\ |
80 | (defined(BOOST_HAS_PARTIAL_STD_ALLOCATOR)||defined(BOOST_DINKUMWARE_STDLIB)) |
81 | |
82 | template<typename Allocator> |
83 | struct is_partial_std_allocator |
84 | { |
85 | BOOST_STATIC_CONSTANT(bool, |
86 | value= |
87 | (is_same< |
88 | std::allocator<BOOST_DEDUCED_TYPENAME Allocator::value_type>, |
89 | Allocator |
90 | >::value)|| |
91 | (is_same< |
92 | partial_std_allocator_wrapper< |
93 | BOOST_DEDUCED_TYPENAME Allocator::value_type>, |
94 | Allocator |
95 | >::value)); |
96 | }; |
97 | |
98 | #else |
99 | |
100 | template<typename Allocator> |
101 | struct is_partial_std_allocator |
102 | { |
103 | BOOST_STATIC_CONSTANT(bool,value=false); |
104 | }; |
105 | |
106 | #endif |
107 | |
108 | /* rebind operations for defective std allocators */ |
109 | |
110 | template<typename Allocator,typename Type> |
111 | struct partial_std_allocator_rebind_to |
112 | { |
113 | typedef partial_std_allocator_wrapper<Type> type; |
114 | }; |
115 | |
116 | /* rebind operation in all other cases */ |
117 | |
118 | template<typename Allocator> |
119 | struct rebinder |
120 | { |
121 | template<typename Type> |
122 | struct result |
123 | { |
124 | typedef typename Allocator::BOOST_NESTED_TEMPLATE |
125 | rebind<Type>::other other; |
126 | }; |
127 | }; |
128 | |
129 | template<typename Allocator,typename Type> |
130 | struct compliant_allocator_rebind_to |
131 | { |
132 | typedef typename rebinder<Allocator>:: |
133 | BOOST_NESTED_TEMPLATE result<Type>::other type; |
134 | }; |
135 | |
136 | /* rebind front-end */ |
137 | |
138 | template<typename Allocator,typename Type> |
139 | struct rebind_to: |
140 | mpl::eval_if_c< |
141 | is_partial_std_allocator<Allocator>::value, |
142 | partial_std_allocator_rebind_to<Allocator,Type>, |
143 | compliant_allocator_rebind_to<Allocator,Type> |
144 | > |
145 | { |
146 | }; |
147 | |
148 | /* allocator-independent versions of construct and destroy */ |
149 | |
150 | template<typename Type> |
151 | void construct(void* p,const Type& t) |
152 | { |
153 | new (p) Type(t); |
154 | } |
155 | |
156 | #if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1500)) |
157 | /* MSVC++ issues spurious warnings about unreferencend formal parameters |
158 | * in destroy<Type> when Type is a class with trivial dtor. |
159 | */ |
160 | |
161 | #pragma warning(push) |
162 | #pragma warning(disable:4100) |
163 | #endif |
164 | |
165 | template<typename Type> |
166 | void destroy(const Type* p) |
167 | { |
168 | |
169 | #if BOOST_WORKAROUND(__SUNPRO_CC,BOOST_TESTED_AT(0x590)) |
170 | const_cast<Type*>(p)->~Type(); |
171 | #else |
172 | p->~Type(); |
173 | #endif |
174 | |
175 | } |
176 | |
177 | #if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1500)) |
178 | #pragma warning(pop) |
179 | #endif |
180 | |
181 | } /* namespace boost::detail::allocator */ |
182 | |
183 | } /* namespace boost::detail */ |
184 | |
185 | } /* namespace boost */ |
186 | |
187 | #endif |
188 | |