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/move/detail/type_traits.hpp>
27 //! The memory_resource class is an abstract interface to an
28 //! unbounded set of classes encapsulating memory resources.
32 // For exposition only
33 static BOOST_CONSTEXPR_OR_CONST std::size_t max_align =
34 boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
36 //! <b>Effects</b>: Destroys
37 //! this memory_resource.
38 virtual ~memory_resource(){}
40 //! <b>Effects</b>: Equivalent to
41 //! `return do_allocate(bytes, alignment);`
42 void* allocate(std::size_t bytes, std::size_t alignment = max_align)
43 { return this->do_allocate(bytes, alignment); }
45 //! <b>Effects</b>: Equivalent to
46 //! `return do_deallocate(bytes, alignment);`
47 void deallocate(void* p, std::size_t bytes, std::size_t alignment = max_align)
48 { return this->do_deallocate(p, bytes, alignment); }
50 //! <b>Effects</b>: Equivalent to
51 //! `return return do_is_equal(other);`
52 bool is_equal(const memory_resource& other) const BOOST_NOEXCEPT
53 { return this->do_is_equal(other); }
56 //! `&a == &b || a.is_equal(b)`.
57 friend bool operator==(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
58 { return &a == &b || a.is_equal(b); }
62 friend bool operator!=(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
66 //! <b>Requires</b>: Alignment shall be a power of two.
68 //! <b>Returns</b>: A derived class shall implement this function to return a pointer
69 //! to allocated storage with a size of at least bytes. The returned storage is
70 //! aligned to the specified alignment, if such alignment is supported; otherwise
71 //! it is aligned to max_align.
73 //! <b>Throws</b>: A derived class implementation shall throw an appropriate exception if
74 //! it is unable to allocate memory with the requested size and alignment.
75 virtual void* do_allocate(std::size_t bytes, std::size_t alignment) = 0;
77 //! <b>Requires</b>: p shall have been returned from a prior call to
78 //! `allocate(bytes, alignment)` on a memory resource equal to *this, and the storage
79 //! at p shall not yet have been deallocated.
81 //! <b>Effects</b>: A derived class shall implement this function to dispose of allocated storage.
83 //! <b>Throws</b>: Nothing.
84 virtual void do_deallocate(void* p, std::size_t bytes, std::size_t alignment) = 0;
86 //! <b>Returns</b>: A derived class shall implement this function to return true if memory
87 //! allocated from this can be deallocated from other and vice-versa; otherwise it shall
88 //! return false. <i>[Note: The most-derived type of other might not match the type of this.
89 //! For a derived class, D, a typical implementation of this function will compute
90 //! `dynamic_cast<const D*>(&other)` and go no further (i.e., return false)
91 //! if it returns nullptr. - end note]</i>.
92 virtual bool do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT = 0;
96 } //namespace container {
99 #include <boost/container/detail/config_end.hpp>
101 #endif //BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP