📄 stl_multimap.h
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// Multimap implementation -*- C++ -*-
// Copyright (C) 2001, 2002, 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) 1996,1997
* 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_multimap.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef _MULTIMAP_H
#define _MULTIMAP_H 1
#include <bits/concept_check.h>
namespace _GLIBCXX_STD
{
// Forward declaration of operators < and ==, needed for friend declaration.
template <typename _Key, typename _Tp,
typename _Compare = less<_Key>,
typename _Alloc = allocator<pair<const _Key, _Tp> > >
class multimap;
template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
inline bool
operator==(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
const multimap<_Key,_Tp,_Compare,_Alloc>& __y);
template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
inline bool
operator<(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
const multimap<_Key,_Tp,_Compare,_Alloc>& __y);
/**
* @brief A standard container made up of (key,value) pairs, which can be
* retrieved based on a key, in logarithmic time.
*
* @ingroup Containers
* @ingroup Assoc_containers
*
* Meets the requirements of a <a href="tables.html#65">container</a>, a
* <a href="tables.html#66">reversible container</a>, and an
* <a href="tables.html#69">associative container</a> (using equivalent
* keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type
* is T, and the value_type is std::pair<const Key,T>.
*
* Multimaps support bidirectional iterators.
*
* @if maint
* The private tree data is declared exactly the same way for map and
* multimap; the distinction is made entirely in how the tree functions are
* called (*_unique versus *_equal, same as the standard).
* @endif
*/
template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
class multimap
{
// concept requirements
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires4(_Compare, bool, _Key, _Key,
_BinaryFunctionConcept)
public:
typedef _Key key_type;
typedef _Tp mapped_type;
typedef pair<const _Key, _Tp> value_type;
typedef _Compare key_compare;
class value_compare
: public binary_function<value_type, value_type, bool>
{
friend class multimap<_Key,_Tp,_Compare,_Alloc>;
protected:
_Compare comp;
value_compare(_Compare __c)
: comp(__c) { }
public:
bool operator()(const value_type& __x, const value_type& __y) const
{ return comp(__x.first, __y.first); }
};
private:
/// @if maint This turns a red-black tree into a [multi]map. @endif
typedef _Rb_tree<key_type, value_type,
_Select1st<value_type>, key_compare, _Alloc> _Rep_type;
/// @if maint The actual tree structure. @endif
_Rep_type _M_t;
public:
// many of these are specified differently in ISO, but the following are
// "functionally equivalent"
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 _Rep_type::allocator_type allocator_type;
typedef typename _Rep_type::iterator iterator;
typedef typename _Rep_type::const_iterator const_iterator;
typedef typename _Rep_type::size_type size_type;
typedef typename _Rep_type::difference_type difference_type;
typedef typename _Rep_type::reverse_iterator reverse_iterator;
typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
// [23.3.2] construct/copy/destroy
// (get_allocator() is also listed in this section)
/**
* @brief Default constructor creates no elements.
*/
multimap()
: _M_t(_Compare(), allocator_type()) { }
// for some reason this was made a separate function
/**
* @brief Default constructor creates no elements.
*/
explicit
multimap(const _Compare& __comp,
const allocator_type& __a = allocator_type())
: _M_t(__comp, __a) { }
/**
* @brief %Multimap copy constructor.
* @param x A %multimap of identical element and allocator types.
*
* The newly-created %multimap uses a copy of the allocation object used
* by @a x.
*/
multimap(const multimap& __x)
: _M_t(__x._M_t) { }
/**
* @brief Builds a %multimap from a range.
* @param first An input iterator.
* @param last An input iterator.
*
* Create a %multimap consisting of copies of the elements from
* [first,last). This is linear in N if the range is already sorted,
* and NlogN otherwise (where N is distance(first,last)).
*/
template <typename _InputIterator>
multimap(_InputIterator __first, _InputIterator __last)
: _M_t(_Compare(), allocator_type())
{ _M_t.insert_equal(__first, __last); }
/**
* @brief Builds a %multimap from a range.
* @param first An input iterator.
* @param last An input iterator.
* @param comp A comparison functor.
* @param a An allocator object.
*
* Create a %multimap consisting of copies of the elements from
* [first,last). This is linear in N if the range is already sorted,
* and NlogN otherwise (where N is distance(first,last)).
*/
template <typename _InputIterator>
multimap(_InputIterator __first, _InputIterator __last,
const _Compare& __comp,
const allocator_type& __a = allocator_type())
: _M_t(__comp, __a)
{ _M_t.insert_equal(__first, __last); }
// FIXME There is no dtor declared, but we should have something generated
// by Doxygen. I don't know what tags to add to this paragraph to make
// that happen:
/**
* 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.
*/
/**
* @brief %Multimap assignment operator.
* @param x A %multimap 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.
*/
multimap&
operator=(const multimap& __x)
{
_M_t = __x._M_t;
return *this;
}
/// Get a copy of the memory allocation object.
allocator_type
get_allocator() const
{ return _M_t.get_allocator(); }
// iterators
/**
* Returns a read/write iterator that points to the first pair in the
* %multimap. Iteration is done in ascending order according to the
* keys.
*/
iterator
begin()
{ return _M_t.begin(); }
/**
* Returns a read-only (constant) iterator that points to the first pair
* in the %multimap. Iteration is done in ascending order according to
* the keys.
*/
const_iterator
begin() const
{ return _M_t.begin(); }
/**
* Returns a read/write iterator that points one past the last pair in
* the %multimap. Iteration is done in ascending order according to the
* keys.
*/
iterator
end()
{ return _M_t.end(); }
/**
* Returns a read-only (constant) iterator that points one past the last
* pair in the %multimap. Iteration is done in ascending order according
* to the keys.
*/
const_iterator
end() const
{ return _M_t.end(); }
/**
* Returns a read/write reverse iterator that points to the last pair in
* the %multimap. Iteration is done in descending order according to the
* keys.
*/
reverse_iterator
rbegin()
{ return _M_t.rbegin(); }
/**
* Returns a read-only (constant) reverse iterator that points to the
* last pair in the %multimap. Iteration is done in descending order
* according to the keys.
*/
const_reverse_iterator
rbegin() const
{ return _M_t.rbegin(); }
/**
* Returns a read/write reverse iterator that points to one before the
* first pair in the %multimap. Iteration is done in descending order
* according to the keys.
*/
reverse_iterator
rend()
{ return _M_t.rend(); }
/**
* Returns a read-only (constant) reverse iterator that points to one
* before the first pair in the %multimap. Iteration is done in
* descending order according to the keys.
*/
const_reverse_iterator
rend() const
{ return _M_t.rend(); }
// capacity
/** Returns true if the %multimap is empty. */
bool
empty() const
{ return _M_t.empty(); }
/** Returns the size of the %multimap. */
size_type
size() const
{ return _M_t.size(); }
/** Returns the maximum size of the %multimap. */
size_type
max_size() const
{ return _M_t.max_size(); }
// modifiers
/**
* @brief Inserts a std::pair into the %multimap.
* @param x Pair to be inserted (see std::make_pair for easy creation
* of pairs).
* @return An iterator that points to the inserted (key,value) pair.
*
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