1 //////////////////////////////////////////////////////////////////////////////
3 // (C) Copyright Ion Gaztanaga 2015-2015. 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)
7 // See http://www.boost.org/libs/container for documentation.
9 //////////////////////////////////////////////////////////////////////////////
11 #ifndef BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP
12 #define BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP
14 #if defined (_MSC_VER)
18 #include <boost/container/detail/config_begin.hpp>
19 #include <boost/container/detail/workaround.hpp>
20 #include <boost/container/container_fwd.hpp>
21 #include <boost/move/detail/type_traits.hpp>
28 //! The memory_resource class is an abstract interface to an
29 //! unbounded set of classes encapsulating memory resources.
30 class BOOST_CONTAINER_DECL memory_resource
33 // For exposition only
34 static BOOST_CONSTEXPR_OR_CONST std::size_t max_align =
35 boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
37 //! <b>Effects</b>: Destroys
38 //! this memory_resource.
39 virtual ~memory_resource(){}
41 //! <b>Effects</b>: Equivalent to
42 //! `return do_allocate(bytes, alignment);`
43 void* allocate(std::size_t bytes, std::size_t alignment = max_align)
44 { return this->do_allocate(bytes, alignment); }
46 //! <b>Effects</b>: Equivalent to
47 //! `return do_deallocate(bytes, alignment);`
48 void deallocate(void* p, std::size_t bytes, std::size_t alignment = max_align)
49 { return this->do_deallocate(p, bytes, alignment); }
51 //! <b>Effects</b>: Equivalent to
52 //! `return return do_is_equal(other);`
53 bool is_equal(const memory_resource& other) const BOOST_NOEXCEPT
54 { return this->do_is_equal(other); }
57 //! `&a == &b || a.is_equal(b)`.
58 friend bool operator==(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
59 { return &a == &b || a.is_equal(b); }
63 friend bool operator!=(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
67 //! <b>Requires</b>: Alignment shall be a power of two.
69 //! <b>Returns</b>: A derived class shall implement this function to return a pointer
70 //! to allocated storage with a size of at least bytes. The returned storage is
71 //! aligned to the specified alignment, if such alignment is supported; otherwise
72 //! it is aligned to max_align.
74 //! <b>Throws</b>: A derived class implementation shall throw an appropriate exception if
75 //! it is unable to allocate memory with the requested size and alignment.
76 virtual void* do_allocate(std::size_t bytes, std::size_t alignment) = 0;
78 //! <b>Requires</b>: p shall have been returned from a prior call to
79 //! `allocate(bytes, alignment)` on a memory resource equal to *this, and the storage
80 //! at p shall not yet have been deallocated.
82 //! <b>Effects</b>: A derived class shall implement this function to dispose of allocated storage.
84 //! <b>Throws</b>: Nothing.
85 virtual void do_deallocate(void* p, std::size_t bytes, std::size_t alignment) = 0;
87 //! <b>Returns</b>: A derived class shall implement this function to return true if memory
88 //! allocated from this can be deallocated from other and vice-versa; otherwise it shall
89 //! return false. <i>[Note: The most-derived type of other might not match the type of this.
90 //! For a derived class, D, a typical implementation of this function will compute
91 //! `dynamic_cast<const D*>(&other)` and go no further (i.e., return false)
92 //! if it returns nullptr. - end note]</i>.
93 virtual bool do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT = 0;
97 } //namespace container {
100 #include <boost/container/detail/config_end.hpp>
102 #endif //BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP