boost/container/pmr/memory_resource.hpp
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2015-2015. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/container for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP
#define BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP
#if defined (_MSC_VER)
# pragma once
#endif
#include <boost/container/detail/config_begin.hpp>
#include <boost/container/detail/workaround.hpp>
#include <boost/container/container_fwd.hpp>
#include <boost/move/detail/type_traits.hpp>
#include <boost/container/detail/placement_new.hpp>
#include <cstddef>
namespace boost {
namespace container {
namespace pmr {
//! The memory_resource class is an abstract interface to an
//! unbounded set of classes encapsulating memory resources.
class memory_resource
{
public:
// For exposition only
BOOST_STATIC_CONSTEXPR std::size_t max_align =
boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
//! <b>Effects</b>: Destroys
//! this memory_resource.
virtual ~memory_resource(){}
//! <b>Effects</b>: Equivalent to
//! `return do_allocate(bytes, alignment);`
void* allocate(std::size_t bytes, std::size_t alignment = max_align)
{
//Obtain a pointer to enough storage and initialize the lifetime
//of an array object of the given size in the address
return ::operator new(bytes, this->do_allocate(bytes, alignment), boost_container_new_t());
}
//! <b>Effects</b>: Equivalent to
//! `return do_deallocate(bytes, alignment);`
void deallocate(void* p, std::size_t bytes, std::size_t alignment = max_align)
{ return this->do_deallocate(p, bytes, alignment); }
//! <b>Effects</b>: Equivalent to
//! `return do_is_equal(other);`
bool is_equal(const memory_resource& other) const BOOST_NOEXCEPT
{ return this->do_is_equal(other); }
#if !defined(BOOST_EMBTC)
//! <b>Returns</b>:
//! `&a == &b || a.is_equal(b)`.
friend bool operator==(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
{ return &a == &b || a.is_equal(b); }
//! <b>Returns</b>:
//! !(a == b).
friend bool operator!=(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
{ return !(a == b); }
#else
//! <b>Returns</b>:
//! `&a == &b || a.is_equal(b)`.
friend bool operator==(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT;
//! <b>Returns</b>:
//! !(a == b).
friend bool operator!=(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT;
#endif
protected:
//! <b>Requires</b>: Alignment shall be a power of two.
//!
//! <b>Returns</b>: A derived class shall implement this function to return a pointer
//! to allocated storage with a size of at least bytes. The returned storage is
//! aligned to the specified alignment, if such alignment is supported; otherwise
//! it is aligned to max_align.
//!
//! <b>Throws</b>: A derived class implementation shall throw an appropriate exception if
//! it is unable to allocate memory with the requested size and alignment.
virtual void* do_allocate(std::size_t bytes, std::size_t alignment) = 0;
//! <b>Requires</b>: p shall have been returned from a prior call to
//! `allocate(bytes, alignment)` on a memory resource equal to *this, and the storage
//! at p shall not yet have been deallocated.
//!
//! <b>Effects</b>: A derived class shall implement this function to dispose of allocated storage.
//!
//! <b>Throws</b>: Nothing.
virtual void do_deallocate(void* p, std::size_t bytes, std::size_t alignment) = 0;
//! <b>Returns</b>: A derived class shall implement this function to return true if memory
//! allocated from this can be deallocated from other and vice-versa; otherwise it shall
//! return false. <i>[Note: The most-derived type of other might not match the type of this.
//! For a derived class, D, a typical implementation of this function will compute
//! `dynamic_cast<const D*>(&other)` and go no further (i.e., return false)
//! if it returns nullptr. - end note]</i>.
virtual bool do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT = 0;
};
#if defined(BOOST_EMBTC)
//! <b>Returns</b>:
//! `&a == &b || a.is_equal(b)`.
inline bool operator==(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
{ return &a == &b || a.is_equal(b); }
//! <b>Returns</b>:
//! !(a == b).
inline bool operator!=(const memory_resource& a, const memory_resource& b) BOOST_NOEXCEPT
{ return !(a == b); }
#endif
} //namespace pmr {
} //namespace container {
} //namespace boost {
#include <boost/container/detail/config_end.hpp>
#endif //BOOST_CONTAINER_PMR_MEMORY_RESOURCE_HPP