libstdc++: std::multimap< _Key, _Tp, _Compare, _Alloc > Class Template Reference

libstdc++

std::multimap< _Key, _Tp, _Compare, _Alloc > Class Template Reference
Containers » Associative

`#include <map>`

## Public Types
typedef _Alloc | allocator_type
typedef _Rep_type::const_iterator | const_iterator
typedef _Alloc_traits::const_pointer | const_pointer
typedef _Alloc_traits::const_reference | const_reference
typedef _Rep_type::const_reverse_iterator | const_reverse_iterator
typedef _Rep_type::difference_type | difference_type
typedef _Rep_type::iterator | iterator
typedef _Compare | key_compare
typedef _Key | key_type
typedef _Tp | mapped_type
typedef _Alloc_traits::pointer | pointer
typedef _Alloc_traits::reference | reference
typedef _Rep_type::reverse_iterator | reverse_iterator
typedef _Rep_type::size_type | size_type
typedef std::pair< const _Key, _Tp > | value_type

## Public Member Functions
| multimap ()=default
template<typename _InputIterator>
| multimap (_InputIterator __first, _InputIterator __last)
template<typename _InputIterator>
| multimap (_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
template<typename _InputIterator>
| multimap (_InputIterator __first, _InputIterator __last, const allocator_type &__a)
| multimap (const _Compare &__comp, const allocator_type &__a=allocator_type())
| multimap (const allocator_type &__a)
| multimap (const multimap &)=default
| multimap (const multimap &__m, const __type_identity_t< allocator_type > &__a)
| multimap (initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
| multimap (initializer_list< value_type > __l, const allocator_type &__a)
| multimap (multimap &&)=default
| multimap (multimap &&__m, const __type_identity_t< allocator_type > &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
| ~multimap ()=default
const_iterator | begin () const noexcept
iterator | begin () noexcept
const_iterator | cbegin () const noexcept
const_iterator | cend () const noexcept
void | clear () noexcept
const_reverse_iterator | crbegin () const noexcept
const_reverse_iterator | crend () const noexcept
template<typename... _Args>
iterator | emplace (_Args &&... __args)
template<typename... _Args>
iterator | emplace_hint (const_iterator __pos, _Args &&... __args)
bool | empty () const noexcept
const_iterator | end () const noexcept
iterator | end () noexcept
size_type | erase (const key_type &__x)
iterator | erase (const_iterator __first, const_iterator __last)
allocator_type | get_allocator () const noexcept
template<typename _InputIterator>
void | insert (_InputIterator __first, _InputIterator __last)
void | insert (initializer_list< value_type > __l)
key_compare | key_comp () const
size_type | max_size () const noexcept
multimap & | operator= (const multimap &)=default
multimap & | operator= (initializer_list< value_type > __l)
multimap & | operator= (multimap &&)=default
const_reverse_iterator | rbegin () const noexcept
reverse_iterator | rbegin () noexcept
const_reverse_iterator | rend () const noexcept
reverse_iterator | rend () noexcept
size_type | size () const noexcept
void | swap (multimap &__x) noexcept(/*conditional */)
value_compare | value_comp () const
iterator | insert (const value_type &__x)
iterator | insert (value_type &&__x)
template<typename _Pair>
__enable_if_t< is_constructible< value_type, _Pair >::value, iterator > | insert (_Pair &&__x)
iterator | insert (const_iterator __position, const value_type &__x)
iterator | insert (const_iterator __position, value_type &&__x)
template<typename _Pair>
__enable_if_t< is_constructible< value_type, _Pair && >::value, iterator > | insert (const_iterator __position, _Pair &&__x)
iterator | erase (const_iterator __position)
iterator | erase (iterator __position)
iterator | find (const key_type &__x)
const_iterator | find (const key_type &__x) const
size_type | count (const key_type &__x) const
bool | contains (const key_type &__x) const
template<typename _Kt>
auto | contains (const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x), void(), true)
iterator | lower_bound (const key_type &__x)
const_iterator | lower_bound (const key_type &__x) const
iterator | upper_bound (const key_type &__x)
const_iterator | upper_bound (const key_type &__x) const
std::pair< iterator, iterator > | equal_range (const key_type &__x)
std::pair< const_iterator, const_iterator > | equal_range (const key_type &__x) const

## Friends
template<typename _K1, typename _T1, typename _C1, typename _A1>
bool | operator< (const multimap< _K1, _T1, _C1, _A1 > &, const multimap< _K1, _T1, _C1, _A1 > &)
template<typename _K1, typename _T1, typename _C1, typename _A1>
bool | operator== (const multimap< _K1, _T1, _C1, _A1 > &, const multimap< _K1, _T1, _C1, _A1 > &)

## Detailed Description

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
class std::multimap< _Key, _Tp, _Compare, _Alloc >

A standard container made up of (key,value) pairs, which can be retrieved based on a key, in logarithmic time.

Since
  C++98

Template Parameters

  _Key | Type of key objects.
  _Tp | Type of mapped objects.
  _Compare | Comparison function object type, defaults to less<_Key>.
  _Alloc | Allocator type, defaults to allocator<pair<const _Key, _Tp>.

Meets the requirements of a container, a reversible container, and an associative container (using equivalent keys). For a `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.

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).

Definition at line 105 of file stl_multimap.h.

## Member Typedef Documentation

## ◆ allocator_type

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Alloc std::multimap< _Key, _Tp, _Compare, _Alloc >::allocator_type

Definition at line 112 of file stl_multimap.h.

## ◆ const_iterator

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Rep_type::const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::const_iterator

Definition at line 172 of file stl_multimap.h.

## ◆ const_pointer

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Alloc_traits::const_pointer std::multimap< _Key, _Tp, _Compare, _Alloc >::const_pointer

Definition at line 168 of file stl_multimap.h.

## ◆ const_reference

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Alloc_traits::const_reference std::multimap< _Key, _Tp, _Compare, _Alloc >::const_reference

Definition at line 170 of file stl_multimap.h.

## ◆ const_reverse_iterator

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Rep_type::const_reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::const_reverse_iterator

Definition at line 176 of file stl_multimap.h.

## ◆ difference_type

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Rep_type::difference_type std::multimap< _Key, _Tp, _Compare, _Alloc >::difference_type

Definition at line 174 of file stl_multimap.h.

## ◆ iterator

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Rep_type::iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::iterator

Definition at line 171 of file stl_multimap.h.

## ◆ key_compare

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Compare std::multimap< _Key, _Tp, _Compare, _Alloc >::key_compare

Definition at line 111 of file stl_multimap.h.

## ◆ key_type

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Key std::multimap< _Key, _Tp, _Compare, _Alloc >::key_type

Definition at line 108 of file stl_multimap.h.

## ◆ mapped_type

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Tp std::multimap< _Key, _Tp, _Compare, _Alloc >::mapped_type

Definition at line 109 of file stl_multimap.h.

## ◆ pointer

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Alloc_traits::pointer std::multimap< _Key, _Tp, _Compare, _Alloc >::pointer

Definition at line 167 of file stl_multimap.h.

## ◆ reference

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Alloc_traits::reference std::multimap< _Key, _Tp, _Compare, _Alloc >::reference

Definition at line 169 of file stl_multimap.h.

## ◆ reverse_iterator

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Rep_type::reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::reverse_iterator

Definition at line 175 of file stl_multimap.h.

## ◆ size_type

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef _Rep_type::size_type std::multimap< _Key, _Tp, _Compare, _Alloc >::size_type

Definition at line 173 of file stl_multimap.h.

## ◆ value_type

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

typedef std::pair<const _Key, _Tp> std::multimap< _Key, _Tp, _Compare, _Alloc >::value_type

Definition at line 110 of file stl_multimap.h.

## Constructor & Destructor Documentation

## ◆ multimap() [1/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( |  | ) |
| default

Default constructor creates no elements.

## ◆ multimap() [2/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | const _Compare & | __comp,
|  | const allocator_type & | __a = allocator_type() )
| inlineexplicit

Creates a multimap with no elements.

Parameters

  __comp | A comparison object.
  __a | An allocator object.

Definition at line 200 of file stl_multimap.h.

## ◆ multimap() [3/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | const multimap< _Key, _Tp, _Compare, _Alloc > & |  | ) |
| default

Multimap copy constructor.

Whether the allocator is copied depends on the allocator traits.

## ◆ multimap() [4/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | multimap< _Key, _Tp, _Compare, _Alloc > && |  | ) |
| default

Multimap move constructor.

The newly-created multimap contains the exact contents of the moved instance. The moved instance is a valid, but unspecified multimap.

## ◆ multimap() [5/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | initializer_list< value_type > | __l,
|  | const _Compare & | __comp = _Compare(),
|  | const allocator_type & | __a = allocator_type() )
| inline

Builds a multimap from an initializer_list.

Parameters

  __l | An initializer_list.
  __comp | A comparison functor.
  __a | An allocator object.

Create a multimap consisting of copies of the elements from the initializer_list. This is linear in N if the list is already sorted, and NlogN otherwise (where N is __l.size()).

Definition at line 234 of file stl_multimap.h.

## ◆ multimap() [6/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | const allocator_type & | __a | ) |
| inlineexplicit

Allocator-extended default constructor.

Definition at line 242 of file stl_multimap.h.

## ◆ multimap() [7/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | const multimap< _Key, _Tp, _Compare, _Alloc > & | __m,
|  | const __type_identity_t< allocator_type > & | __a )
| inline

Allocator-extended copy constructor.

Definition at line 246 of file stl_multimap.h.

## ◆ multimap() [8/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | multimap< _Key, _Tp, _Compare, _Alloc > && | __m,
|  | const __type_identity_t< allocator_type > & | __a )
| inlinenoexcept

Allocator-extended move constructor.

Definition at line 251 of file stl_multimap.h.

## ◆ multimap() [9/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | initializer_list< value_type > | __l,
|  | const allocator_type & | __a )
| inline

Allocator-extended initializer-list constructor.

Definition at line 257 of file stl_multimap.h.

## ◆ multimap() [10/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _InputIterator>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | _InputIterator | __first,
|  | _InputIterator | __last,
|  | const allocator_type & | __a )
| inline

Allocator-extended range constructor.

Definition at line 263 of file stl_multimap.h.

## ◆ multimap() [11/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _InputIterator>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | _InputIterator | __first,
|  | _InputIterator | __last )
| inline

Builds a multimap from a range.

Parameters

  __first | An input iterator.
  __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)).

Definition at line 279 of file stl_multimap.h.

## ◆ multimap() [12/12]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _InputIterator>

std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap | ( | _InputIterator | __first,
|  | _InputIterator | __last,
|  | const _Compare & | __comp,
|  | const allocator_type & | __a = allocator_type() )
| inline

Builds a multimap from a range.

Parameters

  __first | An input iterator.
  __last | An input iterator.
  __comp | A comparison functor.
  __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)).

Definition at line 295 of file stl_multimap.h.

## ◆ ~multimap()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::multimap< _Key, _Tp, _Compare, _Alloc >::~multimap | ( |  | ) |
| default

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 responsibility.

## Member Function Documentation

## ◆ begin() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::begin | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 390 of file stl_multimap.h.

## ◆ begin() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::begin | ( |  | ) |
| inlinenoexcept

Returns a read/write iterator that points to the first pair in the multimap. Iteration is done in ascending order according to the keys.

Definition at line 381 of file stl_multimap.h.

## ◆ cbegin()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::cbegin | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 454 of file stl_multimap.h.

## ◆ cend()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::cend | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 463 of file stl_multimap.h.

## ◆ clear()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

void std::multimap< _Key, _Tp, _Compare, _Alloc >::clear | ( |  | ) |
| inlinenoexcept

Erases all elements in a multimap. 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 responsibility.

Definition at line 871 of file stl_multimap.h.

## ◆ contains() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _Kt>

auto std::multimap< _Key, _Tp, _Compare, _Alloc >::contains | ( | const _Kt & | __x | ) | const -> decltype(_M_t._M_find_tr(__x), void(), true)
| inline

Finds whether an element with the given key exists.

Parameters

  __x | Key of (key, value) pairs to be located.

Returns
  True if there is any element with the specified key.

Definition at line 972 of file stl_multimap.h.

## ◆ contains() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

bool std::multimap< _Key, _Tp, _Compare, _Alloc >::contains | ( | const key_type & | __x | ) | const
| inline

Finds whether an element with the given key exists.

Parameters

  __x | Key of (key, value) pairs to be located.

Returns
  True if there is any element with the specified key.

Definition at line 967 of file stl_multimap.h.

## ◆ count()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

size_type std::multimap< _Key, _Tp, _Compare, _Alloc >::count | ( | const key_type & | __x | ) | const
| inline

Finds the number of elements with given key.

Parameters

  __x | Key of (key, value) pairs to be located.

Returns
  Number of elements with specified key.

Definition at line 948 of file stl_multimap.h.

## ◆ crbegin()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::crbegin | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 472 of file stl_multimap.h.

## ◆ crend()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::crend | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 481 of file stl_multimap.h.

## ◆ emplace()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename... _Args>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::emplace | ( | _Args &&... | __args | ) |
| inline

Build and insert a std::pair into the multimap.

Parameters

  __args | Arguments used to generate a new pair instance (see std::piecewise_contruct for passing arguments to each part of the pair constructor).

Returns
  An iterator that points to the inserted (key,value) pair.

This function builds and inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted.

Insertion requires logarithmic time.

Definition at line 521 of file stl_multimap.h.

## ◆ emplace_hint()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename... _Args>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::emplace_hint | ( | const_iterator | __pos,
|  | _Args &&... | __args )
| inline

Builds and inserts a std::pair into the multimap.

Parameters

  __pos | An iterator that serves as a hint as to where the pair should be inserted.
  __args | Arguments used to generate a new pair instance (see std::piecewise_contruct for passing arguments to each part of the pair constructor).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted. Note that the first parameter is only a hint and can potentially improve the performance of the insertion process. A bad hint would cause no gains in efficiency.

For more on hinting, see: https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

Insertion requires logarithmic time (if the hint is not taken).

Definition at line 548 of file stl_multimap.h.

## ◆ empty()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

bool std::multimap< _Key, _Tp, _Compare, _Alloc >::empty | ( |  | ) | const
| inlinenodiscardnoexcept

Returns true if the multimap is empty.

Definition at line 488 of file stl_multimap.h.

## ◆ end() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::end | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 408 of file stl_multimap.h.

## ◆ end() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::end | ( |  | ) |
| inlinenoexcept

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.

Definition at line 399 of file stl_multimap.h.

## ◆ equal_range() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::pair< iterator, iterator > std::multimap< _Key, _Tp, _Compare, _Alloc >::equal_range | ( | const key_type & | __x | ) |
| inline

Finds a subsequence matching given key.

Parameters

  __x | Key of (key, value) pairs to be located.

Returns
  Pair of iterators that possibly points to the subsequence matching given key.

This function is equivalent to

std::make_pair(c.lower_bound(val),
c.upper_bound(val))
std::make_pair
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition stl_pair.h:1169

(but is faster than making the calls separately).

Definition at line 1083 of file stl_multimap.h.

## ◆ equal_range() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

std::pair< const_iterator, const_iterator > std::multimap< _Key, _Tp, _Compare, _Alloc >::equal_range | ( | const key_type & | __x | ) | const
| inline

Finds a subsequence matching given key.

Parameters

  __x | Key of (key, value) pairs to be located.

Returns
  Pair of read-only (constant) iterators that possibly points to the subsequence matching given key.

This function is equivalent to

std::make_pair(c.lower_bound(val),
c.upper_bound(val))

(but is faster than making the calls separately).

Definition at line 1110 of file stl_multimap.h.

## ◆ erase() [1/4]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

size_type std::multimap< _Key, _Tp, _Compare, _Alloc >::erase | ( | const key_type & | __x | ) |
| inline

Erases elements according to the provided key.

Parameters

  __x | Key of element to be erased.

Returns
  The number of elements erased.

This function erases all elements located by the given key from a multimap. Note 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 responsibility.

Definition at line 795 of file stl_multimap.h.

## ◆ erase() [2/4]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::erase | ( | const_iterator | __first,
|  | const_iterator | __last )
| inline

Erases a [first,last) range of elements from a multimap.

Parameters

  __first | Iterator pointing to the start of the range to be erased.
  __last | Iterator pointing to the end of the range to be erased .

Returns
  The iterator __last.

This function erases a sequence of elements from a multimap. 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 responsibility.

Definition at line 823 of file stl_multimap.h.

## ◆ erase() [3/4]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::erase | ( | const_iterator | __position | ) |
| inline

Erases an element from a multimap.

Parameters

  __position | An iterator pointing to the element to be erased.

Returns
  An iterator pointing to the element immediately following position prior to the element being erased. If no such element exists, end() is returned.

This function erases an element, pointed to by the given iterator, from a multimap. Note 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 responsibility.

Definition at line 758 of file stl_multimap.h.

## ◆ erase() [4/4]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::erase | ( | iterator | __position | ) |
| inline

Erases an element from a multimap.

Parameters

  __position | An iterator pointing to the element to be erased.

Returns
  An iterator pointing to the element immediately following position prior to the element being erased. If no such element exists, end() is returned.

This function erases an element, pointed to by the given iterator, from a multimap. Note 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 responsibility.

Definition at line 764 of file stl_multimap.h.

## ◆ find() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::find | ( | const key_type & | __x | ) |
| inline

Tries to locate an element in a multimap.

Parameters

  __x | Key of (key, value) pair to be located.

Returns
  Iterator pointing to sought-after element, or end() if not found.

This function takes a key and tries to locate the element with which the key matches. If successful the function returns an iterator pointing to the sought after pair. If unsuccessful it returns the past-the-end ( `end()` ) iterator.

Definition at line 906 of file stl_multimap.h.

## ◆ find() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::find | ( | const key_type & | __x | ) | const
| inline

Tries to locate an element in a multimap.

Parameters

  __x | Key of (key, value) pair to be located.

Returns
  Read-only (constant) iterator pointing to sought-after element, or end() if not found.

This function takes a key and tries to locate the element with which the key matches. If successful the function returns a constant iterator pointing to the sought after pair. If unsuccessful it returns the past-the-end ( `end()` ) iterator.

Definition at line 930 of file stl_multimap.h.

## ◆ get_allocator()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

allocator_type std::multimap< _Key, _Tp, _Compare, _Alloc >::get_allocator | ( |  | ) | const
| inlinenoexcept

Get a copy of the memory allocation object.

Definition at line 371 of file stl_multimap.h.

## ◆ insert() [1/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _InputIterator>

void std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | _InputIterator | __first,
|  | _InputIterator | __last )
| inline

A template function that attempts to insert a range of elements.

Parameters

  __first | Iterator pointing to the start of the range to be inserted.
  __last | Iterator pointing to the end of the range.

Complexity similar to that of the range constructor.

Definition at line 643 of file stl_multimap.h.

## ◆ insert() [2/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _Pair>

__enable_if_t< is_constructible< value_type, _Pair >::value, iterator > std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | _Pair && | __x | ) |
| inline

Inserts a std::pair into the multimap.

Parameters

  __x | Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted.

Insertion requires logarithmic time.

Definition at line 581 of file stl_multimap.h.

## ◆ insert() [3/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | const value_type & | __x | ) |
| inline

Inserts a std::pair into the multimap.

Parameters

  __x | Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted.

Insertion requires logarithmic time.

Definition at line 569 of file stl_multimap.h.

Referenced by std::multimap< _Key, _Tp, _Cmp, polymorphic_allocator< pair< const _Key, _Tp > > >::insert().

## ◆ insert() [4/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
template<typename _Pair>

__enable_if_t< is_constructible< value_type, _Pair && >::value, iterator > std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | const_iterator | __position,
|  | _Pair && | __x )
| inline

Inserts a std::pair into the multimap.

Parameters

  __position | An iterator that serves as a hint as to where the pair should be inserted.
  __x | Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted. Note that the first parameter is only a hint and can potentially improve the performance of the insertion process. A bad hint would cause no gains in efficiency.

For more on hinting, see: https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

Insertion requires logarithmic time (if the hint is not taken).

Definition at line 624 of file stl_multimap.h.

## ◆ insert() [5/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | const_iterator | __position,
|  | const value_type & | __x )
| inline

Inserts a std::pair into the multimap.

Parameters

  __position | An iterator that serves as a hint as to where the pair should be inserted.
  __x | Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted. Note that the first parameter is only a hint and can potentially improve the performance of the insertion process. A bad hint would cause no gains in efficiency.

For more on hinting, see: https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

Insertion requires logarithmic time (if the hint is not taken).

Definition at line 609 of file stl_multimap.h.

## ◆ insert() [6/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | const_iterator | __position,
|  | value_type && | __x )
| inline

Inserts a std::pair into the multimap.

Parameters

  __position | An iterator that serves as a hint as to where the pair should be inserted.
  __x | Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted. Note that the first parameter is only a hint and can potentially improve the performance of the insertion process. A bad hint would cause no gains in efficiency.

For more on hinting, see: https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

Insertion requires logarithmic time (if the hint is not taken).

Definition at line 619 of file stl_multimap.h.

## ◆ insert() [7/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

void std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | initializer_list< value_type > | __l | ) |
| inline

Attempts to insert a list of std::pairs into the multimap.

Parameters

  __l | A std::initializer_list<value_type> of pairs to be inserted.

Complexity similar to that of the range constructor.

Definition at line 655 of file stl_multimap.h.

## ◆ insert() [8/8]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::insert | ( | value_type && | __x | ) |
| inline

Inserts a std::pair into the multimap.

Parameters

  __x | Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns
  An iterator that points to the inserted (key,value) pair.

This function inserts a (key, value) pair into the multimap. Contrary to a std::map the multimap does not rely on unique keys and thus multiple pairs with the same key can be inserted.

Insertion requires logarithmic time.

Definition at line 576 of file stl_multimap.h.

## ◆ key_comp()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

key_compare std::multimap< _Key, _Tp, _Compare, _Alloc >::key_comp | ( |  | ) | const
| inline

Returns the key comparison object out of which the multimap was constructed.

Definition at line 880 of file stl_multimap.h.

## ◆ lower_bound() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::lower_bound | ( | const key_type & | __x | ) |
| inline

Finds the beginning of a subsequence matching given key.

Parameters

  __x | Key of (key, value) pair to be located.

Returns
  Iterator pointing to first element equal to or greater than key, or end().

This function returns the first element of a subsequence of elements that matches the given key. If unsuccessful it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

Definition at line 991 of file stl_multimap.h.

## ◆ lower_bound() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::lower_bound | ( | const key_type & | __x | ) | const
| inline

Finds the beginning of a subsequence matching given key.

Parameters

  __x | Key of (key, value) pair to be located.

Returns
  Read-only (constant) iterator pointing to first element equal to or greater than key, or end().

This function returns the first element of a subsequence of elements that matches the given key. If unsuccessful the iterator will point to the next greatest element or, if no such greater element exists, to end().

Definition at line 1016 of file stl_multimap.h.

## ◆ max_size()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

size_type std::multimap< _Key, _Tp, _Compare, _Alloc >::max_size | ( |  | ) | const
| inlinenoexcept

Returns the maximum size of the multimap.

Definition at line 498 of file stl_multimap.h.

## ◆ operator=() [1/3]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

multimap & std::multimap< _Key, _Tp, _Compare, _Alloc >::operator= | ( | const multimap< _Key, _Tp, _Compare, _Alloc > & |  | ) |
| default

Multimap assignment operator.

Whether the allocator is copied depends on the allocator traits.

## ◆ operator=() [2/3]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

multimap & std::multimap< _Key, _Tp, _Compare, _Alloc >::operator= | ( | initializer_list< value_type > | __l | ) |
| inline

Multimap list assignment operator.

Parameters

  __l | An initializer_list.

This function fills a multimap with copies of the elements in the initializer list __l.

Note that the assignment completely changes the multimap and that the resulting multimap's size is the same as the number of elements assigned.

Definition at line 362 of file stl_multimap.h.

## ◆ operator=() [3/3]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

multimap & std::multimap< _Key, _Tp, _Compare, _Alloc >::operator= | ( | multimap< _Key, _Tp, _Compare, _Alloc > && |  | ) |
| default

Move assignment operator.

## ◆ rbegin() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::rbegin | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 426 of file stl_multimap.h.

## ◆ rbegin() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::rbegin | ( |  | ) |
| inlinenoexcept

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.

Definition at line 417 of file stl_multimap.h.

## ◆ rend() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::rend | ( |  | ) | const
| inlinenoexcept

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.

Definition at line 444 of file stl_multimap.h.

## ◆ rend() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

reverse_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::rend | ( |  | ) |
| inlinenoexcept

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.

Definition at line 435 of file stl_multimap.h.

## ◆ size()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

size_type std::multimap< _Key, _Tp, _Compare, _Alloc >::size | ( |  | ) | const
| inlinenoexcept

Returns the size of the multimap.

Definition at line 493 of file stl_multimap.h.

## ◆ swap()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

void std::multimap< _Key, _Tp, _Compare, _Alloc >::swap | ( | multimap< _Key, _Tp, _Compare, _Alloc > & | __x | ) |
| inlinenoexcept

Swaps data with another multimap.

Parameters

  __x | A multimap of the same element and allocator types.

This exchanges the elements between two multimaps in constant time. (It is only swapping a pointer, an integer, and an instance of the `Compare` type (which itself is often stateless and empty), so it should be quite fast.) Note that the global std::swap() function is specialized such that std::swap(m1,m2) will feed to this function.

Whether the allocators are swapped depends on the allocator traits.

Definition at line 860 of file stl_multimap.h.

Referenced by std::swap().

## ◆ upper_bound() [1/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::upper_bound | ( | const key_type & | __x | ) |
| inline

Finds the end of a subsequence matching given key.

Parameters

  __x | Key of (key, value) pair to be located.

Returns
  Iterator pointing to the first element greater than key, or end().

Definition at line 1036 of file stl_multimap.h.

## ◆ upper_bound() [2/2]

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

const_iterator std::multimap< _Key, _Tp, _Compare, _Alloc >::upper_bound | ( | const key_type & | __x | ) | const
| inline

Finds the end of a subsequence matching given key.

Parameters

  __x | Key of (key, value) pair to be located.

Returns
  Read-only (constant) iterator pointing to first iterator greater than key, or end().

Definition at line 1056 of file stl_multimap.h.

## ◆ value_comp()

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

value_compare std::multimap< _Key, _Tp, _Compare, _Alloc >::value_comp | ( |  | ) | const
| inline

Returns a value comparison object, built from the key comparison object out of which the multimap was constructed.

Definition at line 888 of file stl_multimap.h.

The documentation for this class was generated from the following files:

- stl_map.h
- stl_multimap.h