boost/container/node_handle.hpp
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2016-2016. 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_NODE_HANDLE_HPP
#define BOOST_CONTAINER_NODE_HANDLE_HPP
#ifndef BOOST_CONFIG_HPP
# include <boost/config.hpp>
#endif
#if defined(BOOST_HAS_PRAGMA_ONCE)
# pragma once
#endif
#include <boost/container/detail/config_begin.hpp>
#include <boost/container/detail/workaround.hpp>
#include <boost/static_assert.hpp>
#include <boost/container/detail/placement_new.hpp>
#include <boost/container/detail/to_raw_pointer.hpp>
#include <boost/container/allocator_traits.hpp>
#include <boost/container/detail/mpl.hpp>
#include <boost/move/utility_core.hpp>
#include <boost/move/adl_move_swap.hpp>
#include <boost/type_traits/aligned_storage.hpp>
//!\file
namespace boost {
namespace container {
///@cond
template<class Value, class KeyMapped, bool keymapped_is_void = container_detail::is_same<KeyMapped, void>::value>
struct node_handle_keymapped_traits
{
typedef Value key_type;
typedef Value mapped_type;
};
template<class Value, class KeyMapped>
struct node_handle_keymapped_traits<Value, KeyMapped, false>
{
typedef typename KeyMapped::key_type key_type;
typedef typename KeyMapped::mapped_type mapped_type;
};
///@endcond
//! A node_handle is an object that accepts ownership of a single element from an associative container.
//! It may be used to transfer that ownership to another container with compatible nodes. Containers
//! with compatible nodes have the same node handle type. Elements may be transferred in either direction
//! between container types in the same row:.
//!
//! Container types with compatible nodes
//!
//! map<K, T, C1, A> <-> map<K, T, C2, A>
//!
//! map<K, T, C1, A> <-> multimap<K, T, C2, A>
//!
//! set<K, C1, A> <-> set<K, C2, A>
//!
//! set<K, C1, A> <-> multiset<K, C2, A>
//!
//! If a node handle is not empty, then it contains an allocator that is equal to the allocator of the container
//! when the element was extracted. If a node handle is empty, it contains no allocator.
template <class NodeType, class Value, class Allocator, class KeyMapped = void>
class node_handle
{
typedef node_handle_keymapped_traits<Value, KeyMapped> keymapped_t;
public:
typedef Value value_type;
typedef typename keymapped_t::key_type key_type;
typedef typename keymapped_t::mapped_type mapped_type;
typedef Allocator allocator_type;
typedef NodeType container_node_type;
///@cond
private:
BOOST_MOVABLE_BUT_NOT_COPYABLE(node_handle)
typedef allocator_traits<allocator_type> ator_traits;
typedef typename ator_traits::template portable_rebind_alloc
<container_node_type>::type nallocator_type;
typedef allocator_traits<nallocator_type> node_ator_traits;
typedef typename node_ator_traits::pointer node_pointer;
typedef ::boost::aligned_storage
<sizeof(allocator_type), boost::alignment_of<nallocator_type>::value> nalloc_storage_t;
node_pointer m_ptr;
nalloc_storage_t m_nalloc_storage;
void move_construct_alloc(nallocator_type &al)
{ ::new(m_nalloc_storage.address(), boost_container_new_t()) allocator_type(::boost::move(al)); }
void destroy_node()
{
node_ator_traits::destroy(this->node_alloc(), container_detail::to_raw_pointer(m_ptr));
node_ator_traits::deallocate(this->node_alloc(), m_ptr, 1u);
}
template<class OtherNodeHandle>
void move_construct_end(OtherNodeHandle &nh)
{
if(m_ptr){
::new (m_nalloc_storage.address(), boost_container_new_t()) allocator_type(::boost::move(nh.node_alloc()));
nh.destroy_alloc();
nh.get_node_pointer() = node_pointer();
}
BOOST_ASSERT(nh.empty());
}
public:
void destroy_alloc()
{ static_cast<allocator_type*>(m_nalloc_storage.address())->~allocator_type(); }
node_pointer &get_node_pointer()
{ return m_ptr; }
nallocator_type &node_alloc()
{ return *static_cast<nallocator_type*>(m_nalloc_storage.address()); }
node_pointer release()
{
node_pointer p(m_ptr);
m_ptr = node_pointer();
if(p)
this->destroy_alloc();
return p;
}
///@endcond
public:
//! <b>Effects</b>: Initializes m_ptr to nullptr.
//!
//! <b>Postcondition</b>: this->empty()
BOOST_CXX14_CONSTEXPR node_handle() BOOST_NOEXCEPT
: m_ptr(), m_nalloc_storage()
{ BOOST_ASSERT(this->empty()); }
//! <b>Effects</b>: Constructs a node_handle object initializing internal pointer with p.
//! If p != nullptr copy constructs internal allocator al.
node_handle(node_pointer p, const nallocator_type &al) BOOST_NOEXCEPT
: m_ptr(p), m_nalloc_storage()
{
if(m_ptr){
::new (m_nalloc_storage.address(), boost_container_new_t()) nallocator_type(al);
}
}
//! <b>Effects</b>: Constructs a node_handle object initializing internal pointer with a related nh's internal pointer
//! and assigns nullptr to the later. If nh's internal pointer was not nullptr, move constructs internal
//! allocator with nh's internal allocator and destroy nh's internal allocator.
//!
//! <b>Postcondition</b>: nh.empty()
//!
//! <b>Note</b>: Two node_handle's are related if only one of KeyMapped template parameter
//! of a node handle is void.
template<class KeyMapped2>
node_handle( BOOST_RV_REF_BEG node_handle<NodeType, Value, Allocator, KeyMapped2> BOOST_RV_REF_END nh
, typename container_detail::enable_if_c
< ((unsigned)container_detail::is_same<KeyMapped, void>::value +
(unsigned)container_detail::is_same<KeyMapped2, void>::value) == 1u
>::type* = 0)
: m_ptr(nh.get_node_pointer()), m_nalloc_storage()
{ this->move_construct_end(nh); }
//! <b>Effects</b>: Constructs a node_handle object initializing internal pointer with nh's internal pointer
//! and assigns nullptr to the later. If nh's internal pointer was not nullptr, move constructs internal
//! allocator with nh's internal allocator and destroy nh's internal allocator.
//!
//! <b>Postcondition</b>: nh.empty()
node_handle (BOOST_RV_REF(node_handle) nh) BOOST_NOEXCEPT
: m_ptr(nh.m_ptr), m_nalloc_storage()
{ this->move_construct_end(nh); }
//! <b>Effects</b>: If !this->empty(), destroys the value_type subobject in the container_node_type object
//! pointed to by c by calling allocator_traits<impl_defined>::destroy, then deallocates m_ptr by calling
//! ator_traits::rebind_traits<container_node_type>::deallocate.
~node_handle () BOOST_NOEXCEPT
{
if(!this->empty()){
this->destroy_node();
this->destroy_alloc();
}
}
//! <b>Requires</b>: Either this->empty(), or ator_traits::propagate_on_container_move_assignment is true, or
//! node_alloc() == nh.node_alloc().
//!
//! <b>Effects</b>: If m_ptr != nullptr, destroys the value_type subobject in the container_node_type object
//! pointed to by m_ptr by calling ator_traits::destroy, then deallocates m_ptr by calling ator_-
//! traits::rebind_traits<container_node_type>::deallocate. Assigns nh.m_ptr to m_ptr. If this->empty()
//! or ator_traits::propagate_on_container_move_assignment is true, move assigns nh.node_alloc() to
//! node_alloc(). Assigns nullptr to nh.m_ptr and assigns nullopt to nh.node_alloc().
//! <b>Returns</b>: *this.
//!
//! <b>Throws</b>: Nothing.
node_handle & operator=(BOOST_RV_REF(node_handle) nh)
{
BOOST_ASSERT(this->empty() || nh.empty() || ator_traits::propagate_on_container_move_assignment::value
|| ator_traits::equal(node_alloc(), nh.node_alloc()));
bool const was_this_non_null = !this->empty();
bool const was_nh_non_null = !nh.empty();
if(was_nh_non_null){
if(was_this_non_null){
this->destroy_node();
if(ator_traits::propagate_on_container_move_assignment::value){
this->node_alloc() = ::boost::move(nh.node_alloc());
}
}
else{
this->move_construct_alloc(nh.node_alloc());
}
m_ptr = nh.m_ptr;
nh.m_ptr = node_pointer();
nh.destroy_alloc();
}
else if(was_this_non_null){
this->destroy_node();
this->destroy_alloc();
m_ptr = node_pointer();
}
return *this;
}
//! <b>Requires</b>: empty() == false.
//!
//! <b>Returns</b>: A reference to the value_type subobject in the container_node_type object pointed to by m_ptr
//!
//! <b>Throws</b>: Nothing.
value_type& value() const BOOST_NOEXCEPT
{
BOOST_STATIC_ASSERT((container_detail::is_same<KeyMapped, void>::value));
BOOST_ASSERT(!empty());
return m_ptr->get_data();
}
//! <b>Requires</b>: empty() == false.
//!
//! <b>Returns</b>: A non-const reference to the key_type member of the value_type subobject in the
//! container_node_type object pointed to by m_ptr.
//!
//! <b>Throws</b>: Nothing.
//!
//! <b>Requires</b>: Modifying the key through the returned reference is permitted.
key_type& key() const BOOST_NOEXCEPT
{
BOOST_STATIC_ASSERT((!container_detail::is_same<KeyMapped, void>::value));
BOOST_ASSERT(!empty());
return const_cast<key_type &>(KeyMapped().key_of_value(m_ptr->get_data()));
}
//! <b>Requires</b>: empty() == false.
//!
//! <b>Returns</b>: A reference to the mapped_type member of the value_type subobject
//! in the container_node_type object pointed to by m_ptr
//!
//! <b>Throws</b>: Nothing.
mapped_type& mapped() const BOOST_NOEXCEPT
{
BOOST_STATIC_ASSERT((!container_detail::is_same<KeyMapped, void>::value));
BOOST_ASSERT(!empty());
return KeyMapped().mapped_of_value(m_ptr->get_data());
}
//! <b>Requires</b>: empty() == false.
//!
//! <b>Returns</b>: A copy of the internally hold allocator.
//!
//! <b>Throws</b>: Nothing.
allocator_type get_allocator() const
{
BOOST_ASSERT(!empty());
return this->node_alloc();
}
//! <b>Returns</b>: m_ptr != nullptr.
//!
#ifdef BOOST_CONTAINER_DOXYGEN_INVOKED
BOOST_CONTAINER_FORCEINLINE explicit operator bool
#else
private: struct bool_conversion {int for_bool; int for_arg(); }; typedef int bool_conversion::* explicit_bool_arg;
public: BOOST_CONTAINER_FORCEINLINE operator explicit_bool_arg
#endif
()const BOOST_NOEXCEPT
{ return m_ptr ? &bool_conversion::for_bool : explicit_bool_arg(0); }
//! <b>Returns</b>: m_ptr == nullptr.
//!
bool empty() const BOOST_NOEXCEPT
{
return !this->m_ptr;
}
//! <b>Requires</b>: this->empty(), or nh.empty(), or ator_traits::propagate_on_container_swap is true, or
//! node_alloc() == nh.node_alloc().
//!
//! <b>Effects</b>: Calls swap(m_ptr, nh.m_ptr). If this->empty(), or nh.empty(), or ator_traits::propagate_on_-
//! container_swap is true calls swap(node_alloc(), nh.node_alloc()).
void swap(node_handle &nh)
BOOST_NOEXCEPT_IF(ator_traits::propagate_on_container_swap::value || ator_traits::is_always_equal::value)
{
BOOST_ASSERT(this->empty() || nh.empty() || ator_traits::propagate_on_container_swap::value
|| ator_traits::equal(node_alloc(), nh.node_alloc()));
bool const was_this_non_null = !this->empty();
bool const was_nh_non_null = !nh.empty();
if(was_nh_non_null){
if(was_this_non_null){
if(ator_traits::propagate_on_container_swap){
::boost::adl_move_swap(this->node_alloc(), nh.node_alloc());
}
}
else{
this->move_construct_alloc(nh.node_alloc());
nh.destroy_alloc();
}
}
else if(was_this_non_null){
nh.move_construct_alloc(this->node_alloc());
nh.destroy_alloc();
}
::boost::adl_move_swap(m_ptr, nh.m_ptr);
}
//! <b>Effects</b>: x.swap(y).
//!
friend void swap(node_handle & x, node_handle & y) BOOST_NOEXCEPT_IF(BOOST_NOEXCEPT(x.swap(y)))
{ x.swap(y); }
};
//! A class template used to describe the results of inserting a
//! Container::node_type in a Container with unique keys.
//! Includes at least the following non-static public data members:
//!
//! <ul><li>bool inserted</li>;
//! <li>Iterator position</li>;
//! <li>NodeType node</li></ul>
//!
//! This type is MoveConstructible, MoveAssignable, DefaultConstructible,
//! Destructible, and lvalues of that type are swappable
template<class Iterator, class NodeType>
struct insert_return_type_base
{
private:
BOOST_MOVABLE_BUT_NOT_COPYABLE(insert_return_type_base)
public:
insert_return_type_base()
: inserted(false), position(), node()
{}
insert_return_type_base(BOOST_RV_REF(insert_return_type_base) other)
: inserted(other.inserted), position(other.position), node(boost::move(other.node))
{}
template<class RelatedIt, class RelatedNode>
insert_return_type_base(bool insert, RelatedIt it, BOOST_RV_REF(RelatedNode) node)
: inserted(insert), position(it), node(boost::move(node))
{}
insert_return_type_base & operator=(BOOST_RV_REF(insert_return_type_base) other)
{
inserted = other.inserted;
position = other.position;
node = boost::move(other.node);
return *this;
}
bool inserted;
Iterator position;
NodeType node;
};
} //namespace container {
} //namespace boost {
#include <boost/container/detail/config_end.hpp>
#endif //BOOST_CONTAINER_NODE_HANDLE_HPP