整理

include/boost/container/pmr/memory_resource.hpp

@@ -0,0 +1,135 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (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