std::map< _Key, _Tp, _Compare, _Alloc >(3)

NAME
std::map< _Key, _Tp, _Compare, _Alloc > - A standard container made up of (key,value) pairs, which can be retrieved based on a key, in logarithmic time.

SYNOPSIS

#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
using insert_return_type
typedef _Rep_type::iterator iterator
typedef _Compare key_compare
typedef _Key key_type
typedef _Tp mapped_type
using node_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
map ()=default
Default constructor creates no elements.
template<typename _InputIterator > map (_InputIterator __first, _InputIterator __last)
Builds a map from a range.
template<typename _InputIterator > map (_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a map from a range.
template<typename _InputIterator > map (_InputIterator __first, _InputIterator __last, const allocator_type &__a)
Allocator-extended range constructor.
map (const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a map with no elements.
map (const allocator_type &__a)
Allocator-extended default constructor.
map (const map &)=default
Map copy constructor.
map (const map &__m, const __type_identity_t< allocator_type > &__a)
Allocator-extended copy constructor.
map (initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
Builds a map from an initializer_list.
map (initializer_list< value_type > __l, const allocator_type &__a)
Allocator-extended initialier-list constructor.
map (map &&)=default
Map move constructor.
map (map &&__m, const __type_identity_t< allocator_type > &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
Allocator-extended move constructor.
~map ()=default
mapped_type & at (const key_type &__k)
Access to map data.
const mapped_type & at (const key_type &__k) const
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> std::pair< iterator, bool > emplace (_Args &&... __args)
Attempts to build and insert a std::pair into the map.
template<typename... _Args> iterator emplace_hint (const_iterator __pos, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
bool empty () const noexcept
const_iterator end () const noexcept
iterator end () noexcept
size_type erase (const key_type &__x)
Erases elements according to the provided key.
iterator erase (const_iterator __first, const_iterator __last)
Erases a [first,last) range of elements from a map.
node_type extract (const key_type &__x)
Extract a node.
node_type extract (const_iterator __pos)
Extract a node.
allocator_type get_allocator () const noexcept
Get a copy of the memory allocation object.
template<typename _InputIterator > void insert (_InputIterator __first, _InputIterator __last)
Template function that attempts to insert a range of elements.
iterator insert (const_iterator __hint, node_type &&__nh)
Re-insert an extracted node.
insert_return_type insert (node_type &&__nh)
Re-insert an extracted node.
void insert (std::initializer_list< value_type > __list)
Attempts to insert a list of std::pairs into the map.
template<typename _Obj > pair< iterator, bool > insert_or_assign (const key_type &__k, _Obj &&__obj)
Attempts to insert or assign a std::pair into the map.
template<typename _Obj > iterator insert_or_assign (const_iterator __hint, const key_type &__k, _Obj &&__obj)
Attempts to insert or assign a std::pair into the map.
template<typename _Obj > iterator insert_or_assign (const_iterator __hint, key_type &&__k, _Obj &&__obj)
template<typename _Obj > pair< iterator, bool > insert_or_assign (key_type &&__k, _Obj &&__obj)
key_compare key_comp () const
size_type max_size () const noexcept
template<typename _Cmp2 > void merge (map< _Key, _Tp, _Cmp2, _Alloc > &&__source)
template<typename _Cmp2 > void merge (map< _Key, _Tp, _Cmp2, _Alloc > &__source)
template<typename _Cmp2 > void merge (multimap< _Key, _Tp, _Cmp2, _Alloc > &&__source)
template<typename _Cmp2 > void merge (multimap< _Key, _Tp, _Cmp2, _Alloc > &__source)
map & operator= (const map &)=default
Map assignment operator.
map & operator= (initializer_list< value_type > __l)
Map list assignment operator.
map & operator= (map &&)=default
Move assignment operator.
mapped_type & operator[] (const key_type &__k)
Subscript ( [] ) access to map data.
mapped_type & operator[] (key_type &&__k)
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 (map &__x) noexcept(/*conditional */)
Swaps data with another map.
template<typename... _Args> pair< iterator, bool > try_emplace (const key_type &__k, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
template<typename... _Args> iterator try_emplace (const_iterator __hint, const key_type &__k, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
template<typename... _Args> iterator try_emplace (const_iterator __hint, key_type &&__k, _Args &&... __args)
template<typename... _Args> pair< iterator, bool > try_emplace (key_type &&__k, _Args &&... __args)
value_compare value_comp () const

std::pair< iterator, bool > insert (const value_type &__x)
Attempts to insert a std::pair into the map.
std::pair< iterator, bool > insert (value_type &&__x)
Attempts to insert a std::pair into the map.
template<typename _Pair > __enable_if_t< is_constructible< value_type, _Pair >::value, pair< iterator, bool > > insert (_Pair &&__x)
Attempts to insert a std::pair into the map.

iterator insert (const_iterator __position, const value_type &__x)
Attempts to insert a std::pair into the map.
iterator insert (const_iterator __position, value_type &&__x)
Attempts to insert a std::pair into the map.
template<typename _Pair > __enable_if_t< is_constructible< value_type, _Pair >::value, iterator > insert (const_iterator __position, _Pair &&__x)
Attempts to insert a std::pair into the map.

iterator erase (const_iterator __position)
Erases an element from a map.
_GLIBCXX_ABI_TAG_CXX11 iterator erase (iterator __position)
Erases an element from a map.

iterator find (const key_type &__x)
Tries to locate an element in a map.
template<typename _Kt > auto find (const _Kt &__x) -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a map.

const_iterator find (const key_type &__x) const
Tries to locate an element in a map.
template<typename _Kt > auto find (const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a map.

size_type count (const key_type &__x) const
Finds the number of elements with given key.
template<typename _Kt > auto count (const _Kt &__x) const -> decltype(_M_t._M_count_tr(__x))
Finds the number of elements with given key.

bool contains (const key_type &__x) const
Finds whether an element with the given key exists.
template<typename _Kt > auto contains (const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x), void(), true)
Finds whether an element with the given key exists.

iterator lower_bound (const key_type &__x)
Finds the beginning of a subsequence matching given key.
template<typename _Kt > auto lower_bound (const _Kt &__x) -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.

const_iterator lower_bound (const key_type &__x) const
Finds the beginning of a subsequence matching given key.
template<typename _Kt > auto lower_bound (const _Kt &__x) const -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.

iterator upper_bound (const key_type &__x)
Finds the end of a subsequence matching given key.
template<typename _Kt > auto upper_bound (const _Kt &__x) -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.

const_iterator upper_bound (const key_type &__x) const
Finds the end of a subsequence matching given key.
template<typename _Kt > auto upper_bound (const _Kt &__x) const -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.

std::pair< iterator, iterator > equal_range (const key_type &__x)
Finds a subsequence matching given key.
template<typename _Kt > auto equal_range (const _Kt &__x) -> decltype(pair< iterator, iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.

std::pair< const_iterator, const_iterator > equal_range (const key_type &__x) const
Finds a subsequence matching given key.
template<typename _Kt > auto equal_range (const _Kt &__x) const -> decltype(pair< const_iterator, const_iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.

  Friends
template<typename _K1 , typename _T1 , typename _C1 , typename _A1 > __detail::__synth3way_t< pair< const _K1, _T1 > > operator<=> (const map< _K1, _T1, _C1, _A1 > &, const map< _K1, _T1, _C1, _A1 > &)
template<typename _K1 , typename _T1 , typename _C1 , typename _A1 > bool operator== (const map< _K1, _T1, _C1, _A1 > &, const map< _K1, _T1, _C1, _A1 > &)
template<typename , typename > struct std::_Rb_tree_merge_helper

Detailed Description

  template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>
class std::map< _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 unique keys). For a map<Key,T> the key_type is Key, the mapped_type is T, and the value_type is std::pair<const Key,T>.

Maps 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).

Constructor & Destructor Documentation

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map () [default]

Default constructor creates no elements.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const _Compare & __comp, const allocator_type & __a = allocator_type()) [inline], [explicit]

Creates a map with no elements.

Parameters
    __comp A comparison object.
    __a An allocator object.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const map< _Key, _Tp, _Compare, _Alloc > &) [default]

Map copy constructor. Whether the allocator is copied depends on the allocator traits.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (map< _Key, _Tp, _Compare, _Alloc > &&) [default]

Map move constructor. The newly-created map contains the exact contents of the moved instance. The moved instance is a valid, but unspecified, map.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (initializer_list< value_type > __l, const _Compare & __comp = _Compare(), const allocator_type & __a = allocator_type()) [inline]

Builds a map from an initializer_list.

Parameters
    __l An initializer_list.
    __comp A comparison object.
    __a An allocator object.

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

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const allocator_type & __a) [inline], [explicit]

Allocator-extended default constructor.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const map< _Key, _Tp, _Compare, _Alloc > & __m, const __type_identity_t< allocator_type > & __a) [inline]

Allocator-extended copy constructor.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (map< _Key, _Tp, _Compare, _Alloc > && __m, const __type_identity_t< allocator_type > & __a) [inline], [noexcept]

Allocator-extended move constructor.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (initializer_list< value_type > __l, const allocator_type & __a) [inline]

Allocator-extended initialier-list constructor.

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > std::map< _Key, _Tp, _Compare, _Alloc >::map (_InputIterator __first, _InputIterator __last, const allocator_type & __a) [inline]

Allocator-extended range constructor.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > std::map< _Key, _Tp, _Compare, _Alloc >::map (_InputIterator __first, _InputIterator __last) [inline]

Builds a map from a range.

Parameters
    __first An input iterator.
    __last An input iterator.

Create a map 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 _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > std::map< _Key, _Tp, _Compare, _Alloc >::map (_InputIterator __first, _InputIterator __last, const _Compare & __comp, const allocator_type & __a = allocator_type()) [inline]

Builds a map from a range.

Parameters
    __first An input iterator.
    __last An input iterator.
    __comp A comparison functor.
    __a An allocator object.

Create a map 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 _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::~map () [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

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> mapped_type & std::map< _Key, _Tp, _Compare, _Alloc >::at (const key_type & __k) [inline]

Access to map data.

Parameters
    __k The key for which data should be retrieved.

Returns
    A reference to the data whose key is equivalent to __k, if such a data is present in the map.

Exceptions
    std::out_of_range If no such data is present.

References std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::forward(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), and std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::begin () const [inline], [noexcept]
Returns a read-only (constant) iterator that points to the first pair in the map. Iteration is done in ascending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::begin () [inline], [noexcept]
Returns a read/write iterator that points to the first pair in the map. Iteration is done in ascending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::cbegin () const [inline], [noexcept]
Returns a read-only (constant) iterator that points to the first pair in the map. Iteration is done in ascending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::cend () const [inline], [noexcept]
Returns a read-only (constant) iterator that points one past the last pair in the map. Iteration is done in ascending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> void std::map< _Key, _Tp, _Compare, _Alloc >::clear () [inline], [noexcept]
Erases all elements in a map. 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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _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 an element with the specified key.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> bool std::map< _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 an element with the specified key.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::count (const _Kt & __x) const -> decltype(_M_t._M_count_tr(__x))
     [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.

This function only makes sense for multimaps; for map the result will either be 0 (not present) or 1 (present).

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

This function only makes sense for multimaps; for map the result will either be 0 (not present) or 1 (present).

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::crbegin () const [inline], [noexcept]
Returns a read-only (constant) reverse iterator that points to the last pair in the map. Iteration is done in descending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::crend () const [inline], [noexcept]
Returns a read-only (constant) reverse iterator that points to one before the first pair in the map. Iteration is done in descending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> std::pair< iterator, bool > std::map< _Key, _Tp, _Compare, _Alloc >::emplace (_Args &&... __args) [inline]

Attempts to build and insert a std::pair into the map.

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
    A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to build and insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map.

Insertion requires logarithmic time.

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::forward(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), and std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> iterator std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint (const_iterator __pos, _Args &&... __args) [inline]

Attempts to build and insert a std::pair into the map.

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 element with key of the std::pair built from __args (may or may not be that std::pair).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument emplace() does. 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.

See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints for more on hinting.

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

References std::forward().

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::emplace(), std::map< _Key, _Tp, _Compare, _Alloc >::insert(), std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign(), std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign(), std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace(), and std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> bool std::map< _Key, _Tp, _Compare, _Alloc >::empty () const [inline], [noexcept]
Returns true if the map is empty. (Thus begin() would equal end().)

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::end () const [inline], [noexcept]
Returns a read-only (constant) iterator that points one past the last pair in the map. Iteration is done in ascending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::end () [inline], [noexcept]
Returns a read/write iterator that points one past the last pair in the map. Iteration is done in ascending order according to the keys.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::at(), std::map< _Key, _Tp, _Compare, _Alloc >::emplace(), std::map< _Key, _Tp, _Compare, _Alloc >::extract(), std::map< _Key, _Tp, _Compare, _Alloc >::insert(), std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign(), std::map< _Key, _Tp, _Compare, _Alloc >::operator[](), and std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::equal_range (const _Kt & __x) -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__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))

 (but is faster than making the calls separately).

This function probably only makes sense for multimaps.

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::equal_range (const _Kt & __x) const -> decltype(pair<const_iterator, const_iterator>(
          _M_t._M_equal_range_tr(__x)))
     [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).

This function probably only makes sense for multimaps.

References std::forward().

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

 (but is faster than making the calls separately).

This function probably only makes sense for multimaps.

  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::map< _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).

This function probably only makes sense for multimaps.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _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 the elements located by the given key from a map. 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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::erase (const_iterator __first, const_iterator __last) [inline]

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

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 map. 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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::erase (const_iterator __position) [inline]

Erases an element from a map.

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 map. 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.

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> _GLIBCXX_ABI_TAG_CXX11 iterator std::map< _Key, _Tp, _Compare, _Alloc >::erase (iterator __position) [inline]

Erases an element from a map.

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 map. 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.

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> node_type std::map< _Key, _Tp, _Compare, _Alloc >::extract (const key_type & __x) [inline]

Extract a node.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> node_type std::map< _Key, _Tp, _Compare, _Alloc >::extract (const_iterator __pos) [inline]

Extract a node.

References std::map< _Key, _Tp, _Compare, _Alloc >::end(), and std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::find (const _Kt & __x) -> decltype(_M_t._M_find_tr(__x))
     [inline]"

Tries to locate an element in a map.

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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::find (const _Kt & __x) const -> decltype(_M_t._M_find_tr(__x))
     [inline]"

Tries to locate an element in a map.

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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::find (const key_type & __x) [inline]

Tries to locate an element in a map.

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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::find (const key_type & __x) const [inline]

Tries to locate an element in a map.

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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> allocator_type std::map< _Key, _Tp, _Compare, _Alloc >::get_allocator () const [inline], [noexcept]

Get a copy of the memory allocation object.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > void std::map< _Key, _Tp, _Compare, _Alloc >::insert (_InputIterator __first, _InputIterator __last) [inline]

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.

  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, pair< iterator, bool > > std::map< _Key, _Tp, _Compare, _Alloc >::insert (_Pair && __x) [inline]

Attempts to insert a std::pair into the map.

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

Returns
    A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map.

Insertion requires logarithmic time.

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::forward(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), and std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::pair< iterator, bool > std::map< _Key, _Tp, _Compare, _Alloc >::insert (const value_type & __x) [inline]

Attempts to insert a std::pair into the map.

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

Returns
    A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map.

Insertion requires logarithmic time.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::insert (const_iterator __hint, node_type && __nh) [inline]

Re-insert an extracted node.

References std::forward(), and std::move().

  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::map< _Key, _Tp, _Compare, _Alloc >::insert (const_iterator __position, _Pair && __x) [inline]

Attempts to insert a std::pair into the map.

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 element with key of __x (may or may not be the pair passed in).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument insert() does. 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.

See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints for more on hinting.

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

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::insert (const_iterator __position, const value_type & __x) [inline]

Attempts to insert a std::pair into the map.

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 element with key of __x (may or may not be the pair passed in).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument insert() does. 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.

See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints for more on hinting.

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

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::insert (const_iterator __position, value_type && __x) [inline]

Attempts to insert a std::pair into the map.

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 element with key of __x (may or may not be the pair passed in).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument insert() does. 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.

See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints for more on hinting.

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

References std::forward(), and std::move().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> insert_return_type std::map< _Key, _Tp, _Compare, _Alloc >::insert (node_type && __nh) [inline]

Re-insert an extracted node.

References std::forward(), and std::move().

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::insert(), and std::map< _Key, _Tp, _Compare, _Alloc >::operator[]().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> void std::map< _Key, _Tp, _Compare, _Alloc >::insert (std::initializer_list< value_type > __list) [inline]

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

Parameters
    __list A std::initializer_list<value_type> of pairs to be inserted.

Complexity similar to that of the range constructor.

References std::forward(), and std::map< _Key, _Tp, _Compare, _Alloc >::insert().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::pair< iterator, bool > std::map< _Key, _Tp, _Compare, _Alloc >::insert (value_type && __x) [inline]

Attempts to insert a std::pair into the map.

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

Returns
    A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map.

Insertion requires logarithmic time.

References std::move().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Obj > pair< iterator, bool > std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign (const key_type & __k, _Obj && __obj) [inline]

Attempts to insert or assign a std::pair into the map.

Parameters
    __k Key to use for finding a possibly existing pair in the map.
    __obj Argument used to generate the .second for a pair instance.

Returns
    A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map. If the pair was already in the map, the .second of the pair is assigned from __obj.

Insertion requires logarithmic time.

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::forward(), std::forward_as_tuple(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound(), and std::piecewise_construct.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Obj > iterator std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign (const_iterator __hint, const key_type & __k, _Obj && __obj) [inline]

Attempts to insert or assign a std::pair into the map.

Parameters
    __hint An iterator that serves as a hint as to where the pair should be inserted.
    __k Key to use for finding a possibly existing pair in the map.
    __obj Argument used to generate the .second for a pair instance.

Returns
    An iterator that points to the element with key of __x (may or may not be the pair passed in).

This function attempts to insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map. If the pair was already in the map, the .second of the pair is assigned from __obj.

Insertion requires logarithmic time.

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::forward(), std::forward_as_tuple(), and std::piecewise_construct.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> key_compare std::map< _Key, _Tp, _Compare, _Alloc >::key_comp () const [inline]
Returns the key comparison object out of which the map was constructed.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::at(), std::map< _Key, _Tp, _Compare, _Alloc >::emplace(), std::map< _Key, _Tp, _Compare, _Alloc >::insert(), std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign(), std::map< _Key, _Tp, _Compare, _Alloc >::operator[](), and std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound (const _Kt & __x) -> decltype(iterator(_M_t._M_lower_bound_tr(__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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound (const _Kt & __x) const -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
     [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 it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

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

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::at(), std::map< _Key, _Tp, _Compare, _Alloc >::emplace(), std::map< _Key, _Tp, _Compare, _Alloc >::insert(), std::map< _Key, _Tp, _Compare, _Alloc >::insert_or_assign(), std::map< _Key, _Tp, _Compare, _Alloc >::operator[](), and std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _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 it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _Key, _Tp, _Compare, _Alloc >::max_size () const [inline], [noexcept]
Returns the maximum size of the map.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> map & std::map< _Key, _Tp, _Compare, _Alloc >::operator= (const map< _Key, _Tp, _Compare, _Alloc > &) [default]

Map assignment operator. Whether the allocator is copied depends on the allocator traits.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> map & std::map< _Key, _Tp, _Compare, _Alloc >::operator= (initializer_list< value_type > __l) [inline]

Map list assignment operator.

Parameters
    __l An initializer_list.

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

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

References std::forward().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> map & std::map< _Key, _Tp, _Compare, _Alloc >::operator= (map< _Key, _Tp, _Compare, _Alloc > &&) [default]

Move assignment operator.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> mapped_type & std::map< _Key, _Tp, _Compare, _Alloc >::operator[] (const key_type & __k) [inline]

Subscript ( [] ) access to map data.

Parameters
    __k The key for which data should be retrieved.

Returns
    A reference to the data of the (key,data) pair.

Allows for easy lookup with the subscript ( [] ) operator. Returns data associated with the key specified in subscript. If the key does not exist, a pair with that key is created using default values, which is then returned.

Lookup requires logarithmic time.

References std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::forward(), std::map< _Key, _Tp, _Compare, _Alloc >::insert(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound(), and std::piecewise_construct.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rbegin () const [inline], [noexcept]
Returns a read-only (constant) reverse iterator that points to the last pair in the map. Iteration is done in descending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rbegin () [inline], [noexcept]
Returns a read/write reverse iterator that points to the last pair in the map. Iteration is done in descending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rend () const [inline], [noexcept]
Returns a read-only (constant) reverse iterator that points to one before the first pair in the map. Iteration is done in descending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rend () [inline], [noexcept]
Returns a read/write reverse iterator that points to one before the first pair in the map. Iteration is done in descending order according to the keys.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _Key, _Tp, _Compare, _Alloc >::size () const [inline], [noexcept]
Returns the size of the map.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> void std::map< _Key, _Tp, _Compare, _Alloc >::swap (map< _Key, _Tp, _Compare, _Alloc > & __x) [inline], [noexcept]

Swaps data with another map.

Parameters
    __x A map of the same element and allocator types.

This exchanges the elements between two maps 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.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> pair< iterator, bool > std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace (const key_type & __k, _Args &&... __args) [inline]

Attempts to build and insert a std::pair into the map.

Parameters
    __k Key to use for finding a possibly existing pair in the map.
    __args Arguments used to generate the .second for a new pair instance.

Returns
    A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to build and insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map. If a pair is not inserted, this function has no effect.

Insertion requires logarithmic time.

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::forward(), std::forward_as_tuple(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound(), and std::piecewise_construct.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> iterator std::map< _Key, _Tp, _Compare, _Alloc >::try_emplace (const_iterator __hint, const key_type & __k, _Args &&... __args) [inline]

Attempts to build and insert a std::pair into the map.

Parameters
    __hint An iterator that serves as a hint as to where the pair should be inserted.
    __k Key to use for finding a possibly existing pair in the map.
    __args Arguments used to generate the .second for a new pair instance.

Returns
    An iterator that points to the element with key of the std::pair built from __args (may or may not be that std::pair).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument try_emplace() does. However, if insertion did not take place, this function has no effect. 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.

See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints for more on hinting.

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

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::forward(), std::forward_as_tuple(), and std::piecewise_construct.

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::upper_bound (const _Kt & __x) -> decltype(iterator(_M_t._M_upper_bound_tr(__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().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::upper_bound (const _Kt & __x) const -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
     [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().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _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().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _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().

  template<typename _Key , typename _Tp , typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> value_compare std::map< _Key, _Tp, _Compare, _Alloc >::value_comp () const [inline]
Returns a value comparison object, built from the key comparison object out of which the map was constructed.

Author

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