boost/multi_index/detail/node_handle.hpp
/* Copyright 2003-2021 Joaquin M Lopez Munoz.
* 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/multi_index for library home page.
*/
#ifndef BOOST_MULTI_INDEX_DETAIL_NODE_HANDLE_HPP
#define BOOST_MULTI_INDEX_DETAIL_NODE_HANDLE_HPP
#if defined(_MSC_VER)
#pragma once
#endif
#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
#include <algorithm>
#include <boost/core/addressof.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/move/core.hpp>
#include <boost/move/utility_core.hpp>
#include <boost/multi_index_container_fwd.hpp>
#include <boost/multi_index/detail/allocator_traits.hpp>
#include <boost/type_traits/aligned_storage.hpp>
#include <boost/type_traits/alignment_of.hpp>
#include <new>
#if !defined(BOOST_NO_SFINAE)
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/utility/enable_if.hpp>
#endif
namespace boost{
namespace multi_index{
namespace detail{
/* Node handle template class following [container.node] specs.
*/
#include <boost/multi_index/detail/define_if_constexpr_macro.hpp>
template<typename Node,typename Allocator>
class node_handle
{
public:
typedef typename Node::value_type value_type;
typedef Allocator allocator_type;
private:
typedef allocator_traits<allocator_type> alloc_traits;
public:
node_handle()BOOST_NOEXCEPT:node(0){}
node_handle(BOOST_RV_REF(node_handle) x)BOOST_NOEXCEPT:node(x.node)
{
if(!x.empty()){
move_construct_allocator(boost::move(x));
x.destroy_allocator();
x.node=0;
}
}
~node_handle()
{
if(!empty()){
delete_node();
destroy_allocator();
}
}
node_handle& operator=(BOOST_RV_REF(node_handle) x)
{
if(this!=&x){
if(!empty()){
delete_node();
if(!x.empty()){
BOOST_MULTI_INDEX_IF_CONSTEXPR(
alloc_traits::propagate_on_container_move_assignment::value){
move_assign_allocator(boost::move(x));
}
x.destroy_allocator();
}
else{
destroy_allocator();
}
}
else if(!x.empty()){
move_construct_allocator(boost::move(x));
x.destroy_allocator();
}
node=x.node;
x.node=0;
}
return *this;
}
value_type& value()const{return node->value();}
allocator_type get_allocator()const{return *allocator_ptr();}
#if !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
explicit
#endif
operator bool()const BOOST_NOEXCEPT{return (node!=0);}
#if BOOST_WORKAROUND(BOOST_GCC_VERSION,>=70000)&&__cplusplus<201103L
/* https://github.com/boostorg/config/issues/336 */
#else
BOOST_ATTRIBUTE_NODISCARD
#endif
bool empty()const BOOST_NOEXCEPT{return (node==0);}
void swap(node_handle& x)
BOOST_NOEXCEPT_IF(
alloc_traits::propagate_on_container_swap::value||
alloc_traits::is_always_equal::value)
{
if(!empty()){
if(!x.empty()){
BOOST_MULTI_INDEX_IF_CONSTEXPR(
alloc_traits::propagate_on_container_swap::value){
using std::swap;
swap(*allocator_ptr(),*x.allocator_ptr());
}
}
else{
x.move_construct_allocator(boost::move(*this));
destroy_allocator();
}
}
else if(!x.empty()){
move_construct_allocator(boost::move(x));
x.destroy_allocator();
}
std::swap(node,x.node);
}
friend void swap(node_handle& x,node_handle& y)
BOOST_NOEXCEPT_IF(noexcept(x.swap(y)))
{
x.swap(y);
}
private:
BOOST_MOVABLE_BUT_NOT_COPYABLE(node_handle)
template <typename,typename,typename>
friend class boost::multi_index::multi_index_container;
node_handle(Node* node_,const allocator_type& al):node(node_)
{
::new (static_cast<void*>(allocator_ptr())) allocator_type(al);
}
void release_node()
{
if(!empty()){
node=0;
destroy_allocator();
}
}
#include <boost/multi_index/detail/ignore_wstrict_aliasing.hpp>
const allocator_type* allocator_ptr()const
{
return reinterpret_cast<const allocator_type*>(&space);
}
allocator_type* allocator_ptr()
{
return reinterpret_cast<allocator_type*>(&space);
}
#include <boost/multi_index/detail/restore_wstrict_aliasing.hpp>
void move_construct_allocator(BOOST_RV_REF(node_handle) x)
{
::new (static_cast<void*>(allocator_ptr()))
allocator_type(boost::move(*x.allocator_ptr()));
}
void move_assign_allocator(BOOST_RV_REF(node_handle) x)
{
*allocator_ptr()=boost::move(*x.allocator_ptr());
}
void destroy_allocator(){allocator_ptr()->~allocator_type();}
void delete_node()
{
typedef typename rebind_alloc_for<
allocator_type,Node
>::type node_allocator;
typedef detail::allocator_traits<node_allocator> node_alloc_traits;
typedef typename node_alloc_traits::pointer node_pointer;
alloc_traits::destroy(*allocator_ptr(),boost::addressof(node->value()));
node_allocator nal(*allocator_ptr());
node_alloc_traits::deallocate(nal,static_cast<node_pointer>(node),1);
}
Node* node;
typename aligned_storage<
sizeof(allocator_type),
alignment_of<allocator_type>::value
>::type space;
};
#include <boost/multi_index/detail/undef_if_constexpr_macro.hpp>
/* node handle insert return type template class following
* [container.insert.return] specs.
*/
template<typename Iterator,typename NodeHandle>
struct insert_return_type
{
insert_return_type(
Iterator position_,bool inserted_,BOOST_RV_REF(NodeHandle) node_):
position(position_),inserted(inserted_),node(boost::move(node_)){}
insert_return_type(BOOST_RV_REF(insert_return_type) x):
position(x.position),inserted(x.inserted),node(boost::move(x.node)){}
insert_return_type& operator=(BOOST_RV_REF(insert_return_type) x)
{
position=x.position;
inserted=x.inserted;
node=boost::move(x.node);
return *this;
}
Iterator position;
bool inserted;
NodeHandle node;
private:
BOOST_MOVABLE_BUT_NOT_COPYABLE(insert_return_type)
};
/* utility for SFINAEing merge and related operations */
#if !defined(BOOST_NO_SFINAE)
#define BOOST_MULTI_INDEX_ENABLE_IF_MERGEABLE(Dst,Src,T) \
typename enable_if_c< \
!is_const< Dst >::value&&!is_const< Src >::value&& \
is_same<typename Dst::node_type,typename Src::node_type>::value, \
T \
>::type
#else
#define BOOST_MULTI_INDEX_ENABLE_IF_MERGEABLE(Dst,Src,T) T
#endif
} /* namespace multi_index::detail */
} /* namespace multi_index */
} /* namespace boost */
#endif