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gcc/libstdc++-v3/include/bits/stl_deque.h
Paolo Carlini f4e5280b48 [multiple changes] 
2004-11-19  Chris Jefferson  <chris@bubblescope.net>

	* include/bits/stl_list.h (list::back, list::back const):
	Don't decrement temporary.

2004-11-19  Paolo Carlini  <pcarlini@suse.de>

	* include/bits/stl_deque.h (deque::front, deque::front const,
	deque::back, deque::back const): Slightly tweak for stylistic
	consistency.

From-SVN: r90917
2004-11-19 12:44:09 +00:00

1535 lines
51 KiB
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// Deque implementation -*- C++ -*-
// Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file stl_deque.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef _DEQUE_H
#define _DEQUE_H 1
#include <bits/concept_check.h>
#include <bits/stl_iterator_base_types.h>
#include <bits/stl_iterator_base_funcs.h>
namespace _GLIBCXX_STD
{
/**
* @if maint
* @brief This function controls the size of memory nodes.
* @param size The size of an element.
* @return The number (not byte size) of elements per node.
*
* This function started off as a compiler kludge from SGI, but seems to
* be a useful wrapper around a repeated constant expression. The '512' is
* tuneable (and no other code needs to change), but no investigation has
* been done since inheriting the SGI code.
* @endif
*/
inline size_t
__deque_buf_size(size_t __size)
{ return __size < 512 ? size_t(512 / __size) : size_t(1); }
/**
* @brief A deque::iterator.
*
* Quite a bit of intelligence here. Much of the functionality of
* deque is actually passed off to this class. A deque holds two
* of these internally, marking its valid range. Access to
* elements is done as offsets of either of those two, relying on
* operator overloading in this class.
*
* @if maint
* All the functions are op overloads except for _M_set_node.
* @endif
*/
template<typename _Tp, typename _Ref, typename _Ptr>
struct _Deque_iterator
{
typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
static size_t _S_buffer_size()
{ return __deque_buf_size(sizeof(_Tp)); }
typedef random_access_iterator_tag iterator_category;
typedef _Tp value_type;
typedef _Ptr pointer;
typedef _Ref reference;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Tp** _Map_pointer;
typedef _Deque_iterator _Self;
_Tp* _M_cur;
_Tp* _M_first;
_Tp* _M_last;
_Map_pointer _M_node;
_Deque_iterator(_Tp* __x, _Map_pointer __y)
: _M_cur(__x), _M_first(*__y),
_M_last(*__y + _S_buffer_size()), _M_node(__y) {}
_Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
_Deque_iterator(const iterator& __x)
: _M_cur(__x._M_cur), _M_first(__x._M_first),
_M_last(__x._M_last), _M_node(__x._M_node) {}
reference
operator*() const
{ return *_M_cur; }
pointer
operator->() const
{ return _M_cur; }
_Self&
operator++()
{
++_M_cur;
if (_M_cur == _M_last)
{
_M_set_node(_M_node + 1);
_M_cur = _M_first;
}
return *this;
}
_Self
operator++(int)
{
_Self __tmp = *this;
++*this;
return __tmp;
}
_Self&
operator--()
{
if (_M_cur == _M_first)
{
_M_set_node(_M_node - 1);
_M_cur = _M_last;
}
--_M_cur;
return *this;
}
_Self
operator--(int)
{
_Self __tmp = *this;
--*this;
return __tmp;
}
_Self&
operator+=(difference_type __n)
{
const difference_type __offset = __n + (_M_cur - _M_first);
if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
_M_cur += __n;
else
{
const difference_type __node_offset =
__offset > 0 ? __offset / difference_type(_S_buffer_size())
: -difference_type((-__offset - 1)
/ _S_buffer_size()) - 1;
_M_set_node(_M_node + __node_offset);
_M_cur = _M_first + (__offset - __node_offset
* difference_type(_S_buffer_size()));
}
return *this;
}
_Self
operator+(difference_type __n) const
{
_Self __tmp = *this;
return __tmp += __n;
}
_Self&
operator-=(difference_type __n)
{ return *this += -__n; }
_Self
operator-(difference_type __n) const
{
_Self __tmp = *this;
return __tmp -= __n;
}
reference
operator[](difference_type __n) const
{ return *(*this + __n); }
/** @if maint
* Prepares to traverse new_node. Sets everything except
* _M_cur, which should therefore be set by the caller
* immediately afterwards, based on _M_first and _M_last.
* @endif
*/
void
_M_set_node(_Map_pointer __new_node)
{
_M_node = __new_node;
_M_first = *__new_node;
_M_last = _M_first + difference_type(_S_buffer_size());
}
};
// Note: we also provide overloads whose operands are of the same type in
// order to avoid ambiguous overload resolution when std::rel_ops operators
// are in scope (for additional details, see libstdc++/3628)
template<typename _Tp, typename _Ref, typename _Ptr>
inline bool
operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
{ return __x._M_cur == __y._M_cur; }
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline bool
operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{ return __x._M_cur == __y._M_cur; }
template<typename _Tp, typename _Ref, typename _Ptr>
inline bool
operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
{ return !(__x == __y); }
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline bool
operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{ return !(__x == __y); }
template<typename _Tp, typename _Ref, typename _Ptr>
inline bool
operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
{ return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
: (__x._M_node < __y._M_node); }
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline bool
operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{ return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
: (__x._M_node < __y._M_node); }
template<typename _Tp, typename _Ref, typename _Ptr>
inline bool
operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
{ return __y < __x; }
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline bool
operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{ return __y < __x; }
template<typename _Tp, typename _Ref, typename _Ptr>
inline bool
operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
{ return !(__y < __x); }
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline bool
operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{ return !(__y < __x); }
template<typename _Tp, typename _Ref, typename _Ptr>
inline bool
operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
{ return !(__x < __y); }
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline bool
operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{ return !(__x < __y); }
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// According to the resolution of DR179 not only the various comparison
// operators but also operator- must accept mixed iterator/const_iterator
// parameters.
template<typename _Tp, typename _RefL, typename _PtrL,
typename _RefR, typename _PtrR>
inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
{
return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
(_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
* (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
+ (__y._M_last - __y._M_cur);
}
template<typename _Tp, typename _Ref, typename _Ptr>
inline _Deque_iterator<_Tp, _Ref, _Ptr>
operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
{ return __x + __n; }
/**
* @if maint
* Deque base class. This class provides the unified face for %deque's
* allocation. This class's constructor and destructor allocate and
* deallocate (but do not initialize) storage. This makes %exception
* safety easier.
*
* Nothing in this class ever constructs or destroys an actual Tp element.
* (Deque handles that itself.) Only/All memory management is performed
* here.
* @endif
*/
template<typename _Tp, typename _Alloc>
class _Deque_base
{
public:
typedef _Alloc allocator_type;
allocator_type
get_allocator() const
{ return *static_cast<const _Alloc*>(&this->_M_impl); }
typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
_Deque_base(const allocator_type& __a, size_t __num_elements)
: _M_impl(__a)
{ _M_initialize_map(__num_elements); }
_Deque_base(const allocator_type& __a)
: _M_impl(__a)
{ }
~_Deque_base();
protected:
//This struct encapsulates the implementation of the std::deque
//standard container and at the same time makes use of the EBO
//for empty allocators.
struct _Deque_impl
: public _Alloc
{
_Tp** _M_map;
size_t _M_map_size;
iterator _M_start;
iterator _M_finish;
_Deque_impl(const _Alloc& __a)
: _Alloc(__a), _M_map(0), _M_map_size(0), _M_start(), _M_finish()
{ }
};
typedef typename _Alloc::template rebind<_Tp*>::other _Map_alloc_type;
_Map_alloc_type _M_get_map_allocator() const
{ return _Map_alloc_type(this->get_allocator()); }
_Tp*
_M_allocate_node()
{ return _M_impl._Alloc::allocate(__deque_buf_size(sizeof(_Tp))); }
void
_M_deallocate_node(_Tp* __p)
{ _M_impl._Alloc::deallocate(__p, __deque_buf_size(sizeof(_Tp))); }
_Tp**
_M_allocate_map(size_t __n)
{ return _M_get_map_allocator().allocate(__n); }
void
_M_deallocate_map(_Tp** __p, size_t __n)
{ _M_get_map_allocator().deallocate(__p, __n); }
protected:
void _M_initialize_map(size_t);
void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish);
void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish);
enum { _S_initial_map_size = 8 };
_Deque_impl _M_impl;
};
template<typename _Tp, typename _Alloc>
_Deque_base<_Tp, _Alloc>::
~_Deque_base()
{
if (this->_M_impl._M_map)
{
_M_destroy_nodes(this->_M_impl._M_start._M_node,
this->_M_impl._M_finish._M_node + 1);
_M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
}
}
/**
* @if maint
* @brief Layout storage.
* @param num_elements The count of T's for which to allocate space
* at first.
* @return Nothing.
*
* The initial underlying memory layout is a bit complicated...
* @endif
*/
template<typename _Tp, typename _Alloc>
void
_Deque_base<_Tp, _Alloc>::
_M_initialize_map(size_t __num_elements)
{
const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
+ 1);
this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
size_t(__num_nodes + 2));
this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
// For "small" maps (needing less than _M_map_size nodes), allocation
// starts in the middle elements and grows outwards. So nstart may be
// the beginning of _M_map, but for small maps it may be as far in as
// _M_map+3.
_Tp** __nstart = (this->_M_impl._M_map
+ (this->_M_impl._M_map_size - __num_nodes) / 2);
_Tp** __nfinish = __nstart + __num_nodes;
try
{ _M_create_nodes(__nstart, __nfinish); }
catch(...)
{
_M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
this->_M_impl._M_map = 0;
this->_M_impl._M_map_size = 0;
__throw_exception_again;
}
this->_M_impl._M_start._M_set_node(__nstart);
this->_M_impl._M_finish._M_set_node(__nfinish - 1);
this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
+ __num_elements
% __deque_buf_size(sizeof(_Tp)));
}
template<typename _Tp, typename _Alloc>
void
_Deque_base<_Tp, _Alloc>::
_M_create_nodes(_Tp** __nstart, _Tp** __nfinish)
{
_Tp** __cur;
try
{
for (__cur = __nstart; __cur < __nfinish; ++__cur)
*__cur = this->_M_allocate_node();
}
catch(...)
{
_M_destroy_nodes(__nstart, __cur);
__throw_exception_again;
}
}
template<typename _Tp, typename _Alloc>
void
_Deque_base<_Tp, _Alloc>::
_M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish)
{
for (_Tp** __n = __nstart; __n < __nfinish; ++__n)
_M_deallocate_node(*__n);
}
/**
* @brief A standard container using fixed-size memory allocation and
* constant-time manipulation of elements at either end.
*
* @ingroup Containers
* @ingroup Sequences
*
* Meets the requirements of a <a href="tables.html#65">container</a>, a
* <a href="tables.html#66">reversible container</a>, and a
* <a href="tables.html#67">sequence</a>, including the
* <a href="tables.html#68">optional sequence requirements</a>.
*
* In previous HP/SGI versions of deque, there was an extra template
* parameter so users could control the node size. This extension turned
* out to violate the C++ standard (it can be detected using template
* template parameters), and it was removed.
*
* @if maint
* Here's how a deque<Tp> manages memory. Each deque has 4 members:
*
* - Tp** _M_map
* - size_t _M_map_size
* - iterator _M_start, _M_finish
*
* map_size is at least 8. %map is an array of map_size
* pointers-to-"nodes". (The name %map has nothing to do with the
* std::map class, and "nodes" should not be confused with
* std::list's usage of "node".)
*
* A "node" has no specific type name as such, but it is referred
* to as "node" in this file. It is a simple array-of-Tp. If Tp
* is very large, there will be one Tp element per node (i.e., an
* "array" of one). For non-huge Tp's, node size is inversely
* related to Tp size: the larger the Tp, the fewer Tp's will fit
* in a node. The goal here is to keep the total size of a node
* relatively small and constant over different Tp's, to improve
* allocator efficiency.
*
* Not every pointer in the %map array will point to a node. If
* the initial number of elements in the deque is small, the
* /middle/ %map pointers will be valid, and the ones at the edges
* will be unused. This same situation will arise as the %map
* grows: available %map pointers, if any, will be on the ends. As
* new nodes are created, only a subset of the %map's pointers need
* to be copied "outward".
*
* Class invariants:
* - For any nonsingular iterator i:
* - i.node points to a member of the %map array. (Yes, you read that
* correctly: i.node does not actually point to a node.) The member of
* the %map array is what actually points to the node.
* - i.first == *(i.node) (This points to the node (first Tp element).)
* - i.last == i.first + node_size
* - i.cur is a pointer in the range [i.first, i.last). NOTE:
* the implication of this is that i.cur is always a dereferenceable
* pointer, even if i is a past-the-end iterator.
* - Start and Finish are always nonsingular iterators. NOTE: this
* means that an empty deque must have one node, a deque with <N
* elements (where N is the node buffer size) must have one node, a
* deque with N through (2N-1) elements must have two nodes, etc.
* - For every node other than start.node and finish.node, every
* element in the node is an initialized object. If start.node ==
* finish.node, then [start.cur, finish.cur) are initialized
* objects, and the elements outside that range are uninitialized
* storage. Otherwise, [start.cur, start.last) and [finish.first,
* finish.cur) are initialized objects, and [start.first, start.cur)
* and [finish.cur, finish.last) are uninitialized storage.
* - [%map, %map + map_size) is a valid, non-empty range.
* - [start.node, finish.node] is a valid range contained within
* [%map, %map + map_size).
* - A pointer in the range [%map, %map + map_size) points to an allocated
* node if and only if the pointer is in the range
* [start.node, finish.node].
*
* Here's the magic: nothing in deque is "aware" of the discontiguous
* storage!
*
* The memory setup and layout occurs in the parent, _Base, and the iterator
* class is entirely responsible for "leaping" from one node to the next.
* All the implementation routines for deque itself work only through the
* start and finish iterators. This keeps the routines simple and sane,
* and we can use other standard algorithms as well.
* @endif
*/
template<typename _Tp, typename _Alloc = allocator<_Tp> >
class deque : protected _Deque_base<_Tp, _Alloc>
{
// concept requirements
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
typedef _Deque_base<_Tp, _Alloc> _Base;
public:
typedef _Tp value_type;
typedef typename _Alloc::pointer pointer;
typedef typename _Alloc::const_pointer const_pointer;
typedef typename _Alloc::reference reference;
typedef typename _Alloc::const_reference const_reference;
typedef typename _Base::iterator iterator;
typedef typename _Base::const_iterator const_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef typename _Base::allocator_type allocator_type;
protected:
typedef pointer* _Map_pointer;
static size_t _S_buffer_size()
{ return __deque_buf_size(sizeof(_Tp)); }
// Functions controlling memory layout, and nothing else.
using _Base::_M_initialize_map;
using _Base::_M_create_nodes;
using _Base::_M_destroy_nodes;
using _Base::_M_allocate_node;
using _Base::_M_deallocate_node;
using _Base::_M_allocate_map;
using _Base::_M_deallocate_map;
/** @if maint
* A total of four data members accumulated down the heirarchy.
* May be accessed via _M_impl.*
* @endif
*/
using _Base::_M_impl;
public:
// [23.2.1.1] construct/copy/destroy
// (assign() and get_allocator() are also listed in this section)
/**
* @brief Default constructor creates no elements.
*/
explicit
deque(const allocator_type& __a = allocator_type())
: _Base(__a, 0) {}
/**
* @brief Create a %deque with copies of an exemplar element.
* @param n The number of elements to initially create.
* @param value An element to copy.
*
* This constructor fills the %deque with @a n copies of @a value.
*/
deque(size_type __n, const value_type& __value,
const allocator_type& __a = allocator_type())
: _Base(__a, __n)
{ _M_fill_initialize(__value); }
/**
* @brief Create a %deque with default elements.
* @param n The number of elements to initially create.
*
* This constructor fills the %deque with @a n copies of a
* default-constructed element.
*/
explicit
deque(size_type __n)
: _Base(allocator_type(), __n)
{ _M_fill_initialize(value_type()); }
/**
* @brief %Deque copy constructor.
* @param x A %deque of identical element and allocator types.
*
* The newly-created %deque uses a copy of the allocation object used
* by @a x.
*/
deque(const deque& __x)
: _Base(__x.get_allocator(), __x.size())
{ std::__uninitialized_copy_a(__x.begin(), __x.end(),
this->_M_impl._M_start,
this->get_allocator()); }
/**
* @brief Builds a %deque from a range.
* @param first An input iterator.
* @param last An input iterator.
*
* Create a %deque consisting of copies of the elements from [first,
* last).
*
* If the iterators are forward, bidirectional, or random-access, then
* this will call the elements' copy constructor N times (where N is
* distance(first,last)) and do no memory reallocation. But if only
* input iterators are used, then this will do at most 2N calls to the
* copy constructor, and logN memory reallocations.
*/
template<typename _InputIterator>
deque(_InputIterator __first, _InputIterator __last,
const allocator_type& __a = allocator_type())
: _Base(__a)
{
// Check whether it's an integral type. If so, it's not an iterator.
typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
_M_initialize_dispatch(__first, __last, _Integral());
}
/**
* The dtor only erases the elements, and note that if the elements
* themselves are pointers, the pointed-to memory is not touched in any
* way. Managing the pointer is the user's responsibilty.
*/
~deque()
{ std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
this->get_allocator()); }
/**
* @brief %Deque assignment operator.
* @param x A %deque of identical element and allocator types.
*
* All the elements of @a x are copied, but unlike the copy constructor,
* the allocator object is not copied.
*/
deque&
operator=(const deque& __x);
/**
* @brief Assigns a given value to a %deque.
* @param n Number of elements to be assigned.
* @param val Value to be assigned.
*
* This function fills a %deque with @a n copies of the given
* value. Note that the assignment completely changes the
* %deque and that the resulting %deque's size is the same as
* the number of elements assigned. Old data may be lost.
*/
void
assign(size_type __n, const value_type& __val)
{ _M_fill_assign(__n, __val); }
/**
* @brief Assigns a range to a %deque.
* @param first An input iterator.
* @param last An input iterator.
*
* This function fills a %deque with copies of the elements in the
* range [first,last).
*
* Note that the assignment completely changes the %deque and that the
* resulting %deque's size is the same as the number of elements
* assigned. Old data may be lost.
*/
template<typename _InputIterator>
void
assign(_InputIterator __first, _InputIterator __last)
{
typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
_M_assign_dispatch(__first, __last, _Integral());
}
/// Get a copy of the memory allocation object.
allocator_type
get_allocator() const
{ return _Base::get_allocator(); }
// iterators
/**
* Returns a read/write iterator that points to the first element in the
* %deque. Iteration is done in ordinary element order.
*/
iterator
begin()
{ return this->_M_impl._M_start; }
/**
* Returns a read-only (constant) iterator that points to the first
* element in the %deque. Iteration is done in ordinary element order.
*/
const_iterator
begin() const
{ return this->_M_impl._M_start; }
/**
* Returns a read/write iterator that points one past the last
* element in the %deque. Iteration is done in ordinary
* element order.
*/
iterator
end()
{ return this->_M_impl._M_finish; }
/**
* Returns a read-only (constant) iterator that points one past
* the last element in the %deque. Iteration is done in
* ordinary element order.
*/
const_iterator
end() const
{ return this->_M_impl._M_finish; }
/**
* Returns a read/write reverse iterator that points to the
* last element in the %deque. Iteration is done in reverse
* element order.
*/
reverse_iterator
rbegin()
{ return reverse_iterator(this->_M_impl._M_finish); }
/**
* Returns a read-only (constant) reverse iterator that points
* to the last element in the %deque. Iteration is done in
* reverse element order.
*/
const_reverse_iterator
rbegin() const
{ return const_reverse_iterator(this->_M_impl._M_finish); }
/**
* Returns a read/write reverse iterator that points to one
* before the first element in the %deque. Iteration is done
* in reverse element order.
*/
reverse_iterator
rend() { return reverse_iterator(this->_M_impl._M_start); }
/**
* Returns a read-only (constant) reverse iterator that points
* to one before the first element in the %deque. Iteration is
* done in reverse element order.
*/
const_reverse_iterator
rend() const
{ return const_reverse_iterator(this->_M_impl._M_start); }
// [23.2.1.2] capacity
/** Returns the number of elements in the %deque. */
size_type
size() const
{ return this->_M_impl._M_finish - this->_M_impl._M_start; }
/** Returns the size() of the largest possible %deque. */
size_type
max_size() const
{ return size_type(-1); }
/**
* @brief Resizes the %deque to the specified number of elements.
* @param new_size Number of elements the %deque should contain.
* @param x Data with which new elements should be populated.
*
* This function will %resize the %deque to the specified
* number of elements. If the number is smaller than the
* %deque's current size the %deque is truncated, otherwise the
* %deque is extended and new elements are populated with given
* data.
*/
void
resize(size_type __new_size, const value_type& __x)
{
const size_type __len = size();
if (__new_size < __len)
erase(this->_M_impl._M_start + __new_size, this->_M_impl._M_finish);
else
insert(this->_M_impl._M_finish, __new_size - __len, __x);
}
/**
* @brief Resizes the %deque to the specified number of elements.
* @param new_size Number of elements the %deque should contain.
*
* This function will resize the %deque to the specified number
* of elements. If the number is smaller than the %deque's
* current size the %deque is truncated, otherwise the %deque
* is extended and new elements are default-constructed.
*/
void
resize(size_type new_size)
{ resize(new_size, value_type()); }
/**
* Returns true if the %deque is empty. (Thus begin() would
* equal end().)
*/
bool
empty() const
{ return this->_M_impl._M_finish == this->_M_impl._M_start; }
// element access
/**
* @brief Subscript access to the data contained in the %deque.
* @param n The index of the element for which data should be
* accessed.
* @return Read/write reference to data.
*
* This operator allows for easy, array-style, data access.
* Note that data access with this operator is unchecked and
* out_of_range lookups are not defined. (For checked lookups
* see at().)
*/
reference
operator[](size_type __n)
{ return this->_M_impl._M_start[difference_type(__n)]; }
/**
* @brief Subscript access to the data contained in the %deque.
* @param n The index of the element for which data should be
* accessed.
* @return Read-only (constant) reference to data.
*
* This operator allows for easy, array-style, data access.
* Note that data access with this operator is unchecked and
* out_of_range lookups are not defined. (For checked lookups
* see at().)
*/
const_reference
operator[](size_type __n) const
{ return this->_M_impl._M_start[difference_type(__n)]; }
protected:
/// @if maint Safety check used only from at(). @endif
void
_M_range_check(size_type __n) const
{
if (__n >= this->size())
__throw_out_of_range(__N("deque::_M_range_check"));
}
public:
/**
* @brief Provides access to the data contained in the %deque.
* @param n The index of the element for which data should be
* accessed.
* @return Read/write reference to data.
* @throw std::out_of_range If @a n is an invalid index.
*
* This function provides for safer data access. The parameter
* is first checked that it is in the range of the deque. The
* function throws out_of_range if the check fails.
*/
reference
at(size_type __n)
{
_M_range_check(__n);
return (*this)[__n];
}
/**
* @brief Provides access to the data contained in the %deque.
* @param n The index of the element for which data should be
* accessed.
* @return Read-only (constant) reference to data.
* @throw std::out_of_range If @a n is an invalid index.
*
* This function provides for safer data access. The parameter is first
* checked that it is in the range of the deque. The function throws
* out_of_range if the check fails.
*/
const_reference
at(size_type __n) const
{
_M_range_check(__n);
return (*this)[__n];
}
/**
* Returns a read/write reference to the data at the first
* element of the %deque.
*/
reference
front()
{ return *begin(); }
/**
* Returns a read-only (constant) reference to the data at the first
* element of the %deque.
*/
const_reference
front() const
{ return *begin(); }
/**
* Returns a read/write reference to the data at the last element of the
* %deque.
*/
reference
back()
{
iterator __tmp = end();
--__tmp;
return *__tmp;
}
/**
* Returns a read-only (constant) reference to the data at the last
* element of the %deque.
*/
const_reference
back() const
{
const_iterator __tmp = end();
--__tmp;
return *__tmp;
}
// [23.2.1.2] modifiers
/**
* @brief Add data to the front of the %deque.
* @param x Data to be added.
*
* This is a typical stack operation. The function creates an
* element at the front of the %deque and assigns the given
* data to it. Due to the nature of a %deque this operation
* can be done in constant time.
*/
void
push_front(const value_type& __x)
{
if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
{
this->_M_impl.construct(this->_M_impl._M_start._M_cur - 1, __x);
--this->_M_impl._M_start._M_cur;
}
else
_M_push_front_aux(__x);
}
/**
* @brief Add data to the end of the %deque.
* @param x Data to be added.
*
* This is a typical stack operation. The function creates an
* element at the end of the %deque and assigns the given data
* to it. Due to the nature of a %deque this operation can be
* done in constant time.
*/
void
push_back(const value_type& __x)
{
if (this->_M_impl._M_finish._M_cur
!= this->_M_impl._M_finish._M_last - 1)
{
this->_M_impl.construct(this->_M_impl._M_finish._M_cur, __x);
++this->_M_impl._M_finish._M_cur;
}
else
_M_push_back_aux(__x);
}
/**
* @brief Removes first element.
*
* This is a typical stack operation. It shrinks the %deque by one.
*
* Note that no data is returned, and if the first element's data is
* needed, it should be retrieved before pop_front() is called.
*/
void
pop_front()
{
if (this->_M_impl._M_start._M_cur
!= this->_M_impl._M_start._M_last - 1)
{
this->_M_impl.destroy(this->_M_impl._M_start._M_cur);
++this->_M_impl._M_start._M_cur;
}
else
_M_pop_front_aux();
}
/**
* @brief Removes last element.
*
* This is a typical stack operation. It shrinks the %deque by one.
*
* Note that no data is returned, and if the last element's data is
* needed, it should be retrieved before pop_back() is called.
*/
void
pop_back()
{
if (this->_M_impl._M_finish._M_cur
!= this->_M_impl._M_finish._M_first)
{
--this->_M_impl._M_finish._M_cur;
this->_M_impl.destroy(this->_M_impl._M_finish._M_cur);
}
else
_M_pop_back_aux();
}
/**
* @brief Inserts given value into %deque before specified iterator.
* @param position An iterator into the %deque.
* @param x Data to be inserted.
* @return An iterator that points to the inserted data.
*
* This function will insert a copy of the given value before the
* specified location.
*/
iterator
insert(iterator position, const value_type& __x);
/**
* @brief Inserts a number of copies of given data into the %deque.
* @param position An iterator into the %deque.
* @param n Number of elements to be inserted.
* @param x Data to be inserted.
*
* This function will insert a specified number of copies of the given
* data before the location specified by @a position.
*/
void
insert(iterator __position, size_type __n, const value_type& __x)
{ _M_fill_insert(__position, __n, __x); }
/**
* @brief Inserts a range into the %deque.
* @param position An iterator into the %deque.
* @param first An input iterator.
* @param last An input iterator.
*
* This function will insert copies of the data in the range
* [first,last) into the %deque before the location specified
* by @a pos. This is known as "range insert."
*/
template<typename _InputIterator>
void
insert(iterator __position, _InputIterator __first,
_InputIterator __last)
{
// Check whether it's an integral type. If so, it's not an iterator.
typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
_M_insert_dispatch(__position, __first, __last, _Integral());
}
/**
* @brief Remove element at given position.
* @param position Iterator pointing to element to be erased.
* @return An iterator pointing to the next element (or end()).
*
* This function will erase the element at the given position and thus
* shorten the %deque by one.
*
* The user is cautioned that
* this function only erases the element, and that if the element is
* itself a pointer, the pointed-to memory is not touched in any way.
* Managing the pointer is the user's responsibilty.
*/
iterator
erase(iterator __position);
/**
* @brief Remove a range of elements.
* @param first Iterator pointing to the first element to be erased.
* @param last Iterator pointing to one past the last element to be
* erased.
* @return An iterator pointing to the element pointed to by @a last
* prior to erasing (or end()).
*
* This function will erase the elements in the range [first,last) and
* shorten the %deque accordingly.
*
* The user is cautioned that
* this function only erases the elements, and that if the elements
* themselves are pointers, the pointed-to memory is not touched in any
* way. Managing the pointer is the user's responsibilty.
*/
iterator
erase(iterator __first, iterator __last);
/**
* @brief Swaps data with another %deque.
* @param x A %deque of the same element and allocator types.
*
* This exchanges the elements between two deques in constant time.
* (Four pointers, so it should be quite fast.)
* Note that the global std::swap() function is specialized such that
* std::swap(d1,d2) will feed to this function.
*/
void
swap(deque& __x)
{
std::swap(this->_M_impl._M_start, __x._M_impl._M_start);
std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish);
std::swap(this->_M_impl._M_map, __x._M_impl._M_map);
std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size);
}
/**
* Erases all the elements. Note that this function only erases the
* elements, and that if the elements themselves are pointers, the
* pointed-to memory is not touched in any way. Managing the pointer is
* the user's responsibilty.
*/
void clear();
protected:
// Internal constructor functions follow.
// called by the range constructor to implement [23.1.1]/9
template<typename _Integer>
void
_M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
{
_M_initialize_map(__n);
_M_fill_initialize(__x);
}
// called by the range constructor to implement [23.1.1]/9
template<typename _InputIterator>
void
_M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
__false_type)
{
typedef typename iterator_traits<_InputIterator>::iterator_category
_IterCategory;
_M_range_initialize(__first, __last, _IterCategory());
}
// called by the second initialize_dispatch above
//@{
/**
* @if maint
* @brief Fills the deque with whatever is in [first,last).
* @param first An input iterator.
* @param last An input iterator.
* @return Nothing.
*
* If the iterators are actually forward iterators (or better), then the
* memory layout can be done all at once. Else we move forward using
* push_back on each value from the iterator.
* @endif
*/
template<typename _InputIterator>
void
_M_range_initialize(_InputIterator __first, _InputIterator __last,
input_iterator_tag);
// called by the second initialize_dispatch above
template<typename _ForwardIterator>
void
_M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
forward_iterator_tag);
//@}
/**
* @if maint
* @brief Fills the %deque with copies of value.
* @param value Initial value.
* @return Nothing.
* @pre _M_start and _M_finish have already been initialized,
* but none of the %deque's elements have yet been constructed.
*
* This function is called only when the user provides an explicit size
* (with or without an explicit exemplar value).
* @endif
*/
void
_M_fill_initialize(const value_type& __value);
// Internal assign functions follow. The *_aux functions do the actual
// assignment work for the range versions.
// called by the range assign to implement [23.1.1]/9
template<typename _Integer>
void
_M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
{
_M_fill_assign(static_cast<size_type>(__n),
static_cast<value_type>(__val));
}
// called by the range assign to implement [23.1.1]/9
template<typename _InputIterator>
void
_M_assign_dispatch(_InputIterator __first, _InputIterator __last,
__false_type)
{
typedef typename iterator_traits<_InputIterator>::iterator_category
_IterCategory;
_M_assign_aux(__first, __last, _IterCategory());
}
// called by the second assign_dispatch above
template<typename _InputIterator>
void
_M_assign_aux(_InputIterator __first, _InputIterator __last,
input_iterator_tag);
// called by the second assign_dispatch above
template<typename _ForwardIterator>
void
_M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
forward_iterator_tag)
{
const size_type __len = std::distance(__first, __last);
if (__len > size())
{
_ForwardIterator __mid = __first;
std::advance(__mid, size());
std::copy(__first, __mid, begin());
insert(end(), __mid, __last);
}
else
erase(std::copy(__first, __last, begin()), end());
}
// Called by assign(n,t), and the range assign when it turns out
// to be the same thing.
void
_M_fill_assign(size_type __n, const value_type& __val)
{
if (__n > size())
{
std::fill(begin(), end(), __val);
insert(end(), __n - size(), __val);
}
else
{
erase(begin() + __n, end());
std::fill(begin(), end(), __val);
}
}
//@{
/**
* @if maint
* @brief Helper functions for push_* and pop_*.
* @endif
*/
void _M_push_back_aux(const value_type&);
void _M_push_front_aux(const value_type&);
void _M_pop_back_aux();
void _M_pop_front_aux();
//@}
// Internal insert functions follow. The *_aux functions do the actual
// insertion work when all shortcuts fail.
// called by the range insert to implement [23.1.1]/9
template<typename _Integer>
void
_M_insert_dispatch(iterator __pos,
_Integer __n, _Integer __x, __true_type)
{
_M_fill_insert(__pos, static_cast<size_type>(__n),
static_cast<value_type>(__x));
}
// called by the range insert to implement [23.1.1]/9
template<typename _InputIterator>
void
_M_insert_dispatch(iterator __pos,
_InputIterator __first, _InputIterator __last,
__false_type)
{
typedef typename iterator_traits<_InputIterator>::iterator_category
_IterCategory;
_M_range_insert_aux(__pos, __first, __last, _IterCategory());
}
// called by the second insert_dispatch above
template<typename _InputIterator>
void
_M_range_insert_aux(iterator __pos, _InputIterator __first,
_InputIterator __last, input_iterator_tag);
// called by the second insert_dispatch above
template<typename _ForwardIterator>
void
_M_range_insert_aux(iterator __pos, _ForwardIterator __first,
_ForwardIterator __last, forward_iterator_tag);
// Called by insert(p,n,x), and the range insert when it turns out to be
// the same thing. Can use fill functions in optimal situations,
// otherwise passes off to insert_aux(p,n,x).
void
_M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
// called by insert(p,x)
iterator
_M_insert_aux(iterator __pos, const value_type& __x);
// called by insert(p,n,x) via fill_insert
void
_M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
// called by range_insert_aux for forward iterators
template<typename _ForwardIterator>
void
_M_insert_aux(iterator __pos,
_ForwardIterator __first, _ForwardIterator __last,
size_type __n);
//@{
/**
* @if maint
* @brief Memory-handling helpers for the previous internal insert
* functions.
* @endif
*/
iterator
_M_reserve_elements_at_front(size_type __n)
{
const size_type __vacancies = this->_M_impl._M_start._M_cur
- this->_M_impl._M_start._M_first;
if (__n > __vacancies)
_M_new_elements_at_front(__n - __vacancies);
return this->_M_impl._M_start - difference_type(__n);
}
iterator
_M_reserve_elements_at_back(size_type __n)
{
const size_type __vacancies = (this->_M_impl._M_finish._M_last
- this->_M_impl._M_finish._M_cur) - 1;
if (__n > __vacancies)
_M_new_elements_at_back(__n - __vacancies);
return this->_M_impl._M_finish + difference_type(__n);
}
void
_M_new_elements_at_front(size_type __new_elements);
void
_M_new_elements_at_back(size_type __new_elements);
//@}
//@{
/**
* @if maint
* @brief Memory-handling helpers for the major %map.
*
* Makes sure the _M_map has space for new nodes. Does not
* actually add the nodes. Can invalidate _M_map pointers.
* (And consequently, %deque iterators.)
* @endif
*/
void
_M_reserve_map_at_back (size_type __nodes_to_add = 1)
{
if (__nodes_to_add + 1 > this->_M_impl._M_map_size
- (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
_M_reallocate_map(__nodes_to_add, false);
}
void
_M_reserve_map_at_front (size_type __nodes_to_add = 1)
{
if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
- this->_M_impl._M_map))
_M_reallocate_map(__nodes_to_add, true);
}
void
_M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
//@}
};
/**
* @brief Deque equality comparison.
* @param x A %deque.
* @param y A %deque of the same type as @a x.
* @return True iff the size and elements of the deques are equal.
*
* This is an equivalence relation. It is linear in the size of the
* deques. Deques are considered equivalent if their sizes are equal,
* and if corresponding elements compare equal.
*/
template<typename _Tp, typename _Alloc>
inline bool
operator==(const deque<_Tp, _Alloc>& __x,
const deque<_Tp, _Alloc>& __y)
{ return __x.size() == __y.size()
&& std::equal(__x.begin(), __x.end(), __y.begin()); }
/**
* @brief Deque ordering relation.
* @param x A %deque.
* @param y A %deque of the same type as @a x.
* @return True iff @a x is lexicographically less than @a y.
*
* This is a total ordering relation. It is linear in the size of the
* deques. The elements must be comparable with @c <.
*
* See std::lexicographical_compare() for how the determination is made.
*/
template<typename _Tp, typename _Alloc>
inline bool
operator<(const deque<_Tp, _Alloc>& __x,
const deque<_Tp, _Alloc>& __y)
{ return lexicographical_compare(__x.begin(), __x.end(),
__y.begin(), __y.end()); }
/// Based on operator==
template<typename _Tp, typename _Alloc>
inline bool
operator!=(const deque<_Tp, _Alloc>& __x,
const deque<_Tp, _Alloc>& __y)
{ return !(__x == __y); }
/// Based on operator<
template<typename _Tp, typename _Alloc>
inline bool
operator>(const deque<_Tp, _Alloc>& __x,
const deque<_Tp, _Alloc>& __y)
{ return __y < __x; }
/// Based on operator<
template<typename _Tp, typename _Alloc>
inline bool
operator<=(const deque<_Tp, _Alloc>& __x,
const deque<_Tp, _Alloc>& __y)
{ return !(__y < __x); }
/// Based on operator<
template<typename _Tp, typename _Alloc>
inline bool
operator>=(const deque<_Tp, _Alloc>& __x,
const deque<_Tp, _Alloc>& __y)
{ return !(__x < __y); }
/// See std::deque::swap().
template<typename _Tp, typename _Alloc>
inline void
swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
{ __x.swap(__y); }
} // namespace std
#endif /* _DEQUE_H */
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