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

libstdc++

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

`#include <set>`

## Public Types
typedef _Key | key_type
typedef _Key | value_type
typedef _Compare | key_compare
typedef _Compare | value_compare
typedef _Alloc | allocator_type
typedef _Alloc_traits::pointer | pointer
typedef _Alloc_traits::const_pointer | const_pointer
typedef _Alloc_traits::reference | reference
typedef _Alloc_traits::const_reference | const_reference
typedef _Rep_type::const_iterator | iterator
typedef _Rep_type::const_iterator | const_iterator
typedef _Rep_type::const_reverse_iterator | reverse_iterator
typedef _Rep_type::const_reverse_iterator | const_reverse_iterator
typedef _Rep_type::size_type | size_type
typedef _Rep_type::difference_type | difference_type

## Public Member Functions
| set ()=default
template<typename _InputIterator>
| set (_InputIterator __first, _InputIterator __last)
template<typename _InputIterator>
| set (_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
template<typename _InputIterator>
| set (_InputIterator __first, _InputIterator __last, const allocator_type &__a)
| set (const _Compare &__comp, const allocator_type &__a=allocator_type())
| set (const allocator_type &__a)
| set (const set &)=default
| set (const set &__x, const __type_identity_t< allocator_type > &__a)
| set (initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
| set (initializer_list< value_type > __l, const allocator_type &__a)
| set (set &&)=default
| set (set &&__x, const __type_identity_t< allocator_type > &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
| ~set ()=default
iterator | begin () const noexcept
iterator | cbegin () const noexcept
iterator | cend () const noexcept
void | clear () noexcept
reverse_iterator | crbegin () const noexcept
reverse_iterator | crend () const noexcept
template<typename... _Args>
std::pair< iterator, bool > | emplace (_Args &&... __args)
template<typename... _Args>
iterator | emplace_hint (const_iterator __pos, _Args &&... __args)
bool | empty () const noexcept
iterator | end () const noexcept
size_type | erase (const key_type &__x)
iterator | erase (const_iterator __first, const_iterator __last)
iterator | erase (const_iterator __position)
allocator_type | get_allocator () const noexcept
template<typename _InputIterator>
void | insert (_InputIterator __first, _InputIterator __last)
std::pair< iterator, bool > | insert (const value_type &__x)
void | insert (initializer_list< value_type > __l)
std::pair< iterator, bool > | insert (value_type &&__x)
key_compare | key_comp () const
size_type | max_size () const noexcept
set & | operator= (const set &)=default
set & | operator= (initializer_list< value_type > __l)
set & | operator= (set &&)=default
reverse_iterator | rbegin () const noexcept
reverse_iterator | rend () const noexcept
size_type | size () const noexcept
void | swap (set &__x) noexcept(/*conditional */)
value_compare | value_comp () const
iterator | insert (const_iterator __position, const value_type &__x)
iterator | insert (const_iterator __position, value_type &&__x)
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 | find (const key_type &__x)
const_iterator | find (const key_type &__x) const
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 _C1, typename _A1>
bool | operator< (const set< _K1, _C1, _A1 > &, const set< _K1, _C1, _A1 > &)
template<typename _K1, typename _C1, typename _A1>
bool | operator== (const set< _K1, _C1, _A1 > &, const set< _K1, _C1, _A1 > &)

## Detailed Description

template<typename _Key, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<_Key>>
class std::set< _Key, _Compare, _Alloc >

A standard container made up of unique keys, which can be retrieved in logarithmic time.

Since
  C++98

Template Parameters

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

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

Sets support bidirectional iterators.

The private tree data is declared exactly the same way for set and multiset; the distinction is made entirely in how the tree functions are called (*_unique versus *_equal, same as the standard).

Definition at line 100 of file stl_set.h.

## Member Typedef Documentation

## ◆ allocator_type

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

typedef _Alloc std::set< _Key, _Compare, _Alloc >::allocator_type

Public typedefs.

Definition at line 130 of file stl_set.h.

## ◆ const_iterator

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

typedef _Rep_type::const_iterator std::set< _Key, _Compare, _Alloc >::const_iterator

Iterator-related typedefs.

Definition at line 154 of file stl_set.h.

## ◆ const_pointer

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

typedef _Alloc_traits::const_pointer std::set< _Key, _Compare, _Alloc >::const_pointer

Iterator-related typedefs.

Definition at line 147 of file stl_set.h.

## ◆ const_reference

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

typedef _Alloc_traits::const_reference std::set< _Key, _Compare, _Alloc >::const_reference

Iterator-related typedefs.

Definition at line 149 of file stl_set.h.

## ◆ const_reverse_iterator

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

typedef _Rep_type::const_reverse_iterator std::set< _Key, _Compare, _Alloc >::const_reverse_iterator

Iterator-related typedefs.

Definition at line 156 of file stl_set.h.

## ◆ difference_type

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

typedef _Rep_type::difference_type std::set< _Key, _Compare, _Alloc >::difference_type

Iterator-related typedefs.

Definition at line 158 of file stl_set.h.

## ◆ iterator

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

typedef _Rep_type::const_iterator std::set< _Key, _Compare, _Alloc >::iterator

Iterator-related typedefs.

Definition at line 153 of file stl_set.h.

## ◆ key_compare

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

typedef _Compare std::set< _Key, _Compare, _Alloc >::key_compare

Public typedefs.

Definition at line 128 of file stl_set.h.

## ◆ key_type

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

typedef _Key std::set< _Key, _Compare, _Alloc >::key_type

Public typedefs.

Definition at line 126 of file stl_set.h.

## ◆ pointer

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

typedef _Alloc_traits::pointer std::set< _Key, _Compare, _Alloc >::pointer

Iterator-related typedefs.

Definition at line 146 of file stl_set.h.

## ◆ reference

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

typedef _Alloc_traits::reference std::set< _Key, _Compare, _Alloc >::reference

Iterator-related typedefs.

Definition at line 148 of file stl_set.h.

## ◆ reverse_iterator

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

typedef _Rep_type::const_reverse_iterator std::set< _Key, _Compare, _Alloc >::reverse_iterator

Iterator-related typedefs.

Definition at line 155 of file stl_set.h.

## ◆ size_type

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

typedef _Rep_type::size_type std::set< _Key, _Compare, _Alloc >::size_type

Iterator-related typedefs.

Definition at line 157 of file stl_set.h.

## ◆ value_compare

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

typedef _Compare std::set< _Key, _Compare, _Alloc >::value_compare

Public typedefs.

Definition at line 129 of file stl_set.h.

## ◆ value_type

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

typedef _Key std::set< _Key, _Compare, _Alloc >::value_type

Public typedefs.

Definition at line 127 of file stl_set.h.

## Constructor & Destructor Documentation

## ◆ set() [1/12]

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

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

Default constructor creates no elements.

## ◆ set() [2/12]

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

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

Creates a set with no elements.

Parameters

  __comp | Comparator to use.
  __a | An allocator object.

Definition at line 182 of file stl_set.h.

## ◆ set() [3/12]

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

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

Builds a set from a range.

Parameters

  __first | An input iterator.
  __last | An input iterator.

Create a set 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 197 of file stl_set.h.

## ◆ set() [4/12]

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

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

Builds a set from a range.

Parameters

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

Create a set 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 214 of file stl_set.h.

## ◆ set() [5/12]

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

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

Set copy constructor.

Whether the allocator is copied depends on the allocator traits.

## ◆ set() [6/12]

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

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

Set move constructor

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

## ◆ set() [7/12]

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

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

Builds a set from an initializer_list.

Parameters

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

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

Definition at line 249 of file stl_set.h.

## ◆ set() [8/12]

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

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

Allocator-extended default constructor.

Definition at line 257 of file stl_set.h.

## ◆ set() [9/12]

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

std::set< _Key, _Compare, _Alloc >::set | ( | const set< _Key, _Compare, _Alloc > & | __x,
|  | const __type_identity_t< allocator_type > & | __a )
| inline

Allocator-extended copy constructor.

Definition at line 261 of file stl_set.h.

## ◆ set() [10/12]

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

std::set< _Key, _Compare, _Alloc >::set | ( | set< _Key, _Compare, _Alloc > && | __x,
|  | const __type_identity_t< allocator_type > & | __a )
| inlinenoexcept

Allocator-extended move constructor.

Definition at line 265 of file stl_set.h.

## ◆ set() [11/12]

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

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

Allocator-extended initializer-list constructor.

Definition at line 271 of file stl_set.h.

## ◆ set() [12/12]

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

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

Allocator-extended range constructor.

Definition at line 277 of file stl_set.h.

## ◆ ~set()

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

std::set< _Key, _Compare, _Alloc >::~set | ( |  | ) |
| 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()

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

iterator std::set< _Key, _Compare, _Alloc >::begin | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) iterator that points to the first element in the set. Iteration is done in ascending order according to the keys.

Definition at line 369 of file stl_set.h.

## ◆ cbegin()

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

iterator std::set< _Key, _Compare, _Alloc >::cbegin | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) iterator that points to the first element in the set. Iteration is done in ascending order according to the keys.

Definition at line 406 of file stl_set.h.

## ◆ cend()

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

iterator std::set< _Key, _Compare, _Alloc >::cend | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) iterator that points one past the last element in the set. Iteration is done in ascending order according to the keys.

Definition at line 415 of file stl_set.h.

## ◆ clear()

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

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

Erases all elements in a set. 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 833 of file stl_set.h.

## ◆ contains() [1/2]

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

auto std::set< _Key, _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 elements to be located.

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

Definition at line 873 of file stl_set.h.

## ◆ contains() [2/2]

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

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

Finds whether an element with the given key exists.

Parameters

  __x | Key of elements to be located.

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

Definition at line 868 of file stl_set.h.

## ◆ count()

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

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

Finds the number of elements.

Parameters

  __x | Element to located.

Returns
  Number of elements with specified key.

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

Definition at line 848 of file stl_set.h.

## ◆ crbegin()

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

reverse_iterator std::set< _Key, _Compare, _Alloc >::crbegin | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) iterator that points to the last element in the set. Iteration is done in descending order according to the keys.

Definition at line 424 of file stl_set.h.

## ◆ crend()

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

reverse_iterator std::set< _Key, _Compare, _Alloc >::crend | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) reverse iterator that points to the last pair in the set. Iteration is done in descending order according to the keys.

Definition at line 433 of file stl_set.h.

## ◆ emplace()

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

std::pair< iterator, bool > std::set< _Key, _Compare, _Alloc >::emplace | ( | _Args &&... | __args | ) |
| inline

Attempts to build and insert an element into the set.

Parameters

  __args | Arguments used to generate an element.

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

This function attempts to build and insert an element into the set. A set relies on unique keys and thus an element is only inserted if it is not already present in the set.

Insertion requires logarithmic time.

Definition at line 487 of file stl_set.h.

## ◆ emplace_hint()

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

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

Attempts to insert an element into the set.

Parameters

  __pos | An iterator that serves as a hint as to where the element should be inserted.
  __args | Arguments used to generate the element to be inserted.

Returns
  An iterator that points to the element with key equivalent to the one generated from __args (may or may not be the element itself).

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.

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 513 of file stl_set.h.

## ◆ empty()

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

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

Returns true if the set is empty.

Definition at line 439 of file stl_set.h.

## ◆ end()

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

iterator std::set< _Key, _Compare, _Alloc >::end | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) iterator that points one past the last element in the set. Iteration is done in ascending order according to the keys.

Definition at line 378 of file stl_set.h.

## ◆ equal_range() [1/2]

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

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

Finds a subsequence matching given key.

Parameters

  __x | Key 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).

This function probably only makes sense for multisets.

Definition at line 998 of file stl_set.h.

## ◆ equal_range() [2/2]

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

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

Finds a subsequence matching given key.

Parameters

  __x | Key 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 multisets.

Definition at line 1002 of file stl_set.h.

## ◆ erase() [1/3]

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

size_type std::set< _Key, _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 set. 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 774 of file stl_set.h.

## ◆ erase() [2/3]

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

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

Erases a [__first,__last) range of elements from a set.

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 set. 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 806 of file stl_set.h.

## ◆ erase() [3/3]

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

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

Erases an element from a set.

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 set. 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 744 of file stl_set.h.

## ◆ find() [1/2]

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

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

Tries to locate an element in a set.

Parameters

  __x | Element 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 element. If unsuccessful it returns the past-the-end ( `end()` ) iterator.

Definition at line 894 of file stl_set.h.

## ◆ find() [2/2]

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

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

Tries to locate an element in a set.

Parameters

  __x | Element 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 element. If unsuccessful it returns the past-the-end ( `end()` ) iterator.

Definition at line 898 of file stl_set.h.

## ◆ get_allocator()

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

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

Returns the allocator object with which the set was constructed.

Definition at line 360 of file stl_set.h.

## ◆ insert() [1/6]

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

void std::set< _Key, _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 627 of file stl_set.h.

## ◆ insert() [2/6]

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

std::pair< iterator, bool > std::set< _Key, _Compare, _Alloc >::insert | ( | const value_type & | __x | ) |
| inline

Attempts to insert an element into the set.

Parameters

  __x | Element to be inserted.

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

This function attempts to insert an element into the set. A set relies on unique keys and thus an element is only inserted if it is not already present in the set.

Insertion requires logarithmic time.

Definition at line 534 of file stl_set.h.

Referenced by std::set< _Key, _Cmp, polymorphic_allocator< _Key > >::insert().

## ◆ insert() [3/6]

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

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

Attempts to insert an element into the set.

Parameters

  __position | An iterator that serves as a hint as to where the element should be inserted.
  __x | Element to be inserted.

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

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

If a heterogeneous key __k matches a range of elements, an iterator to the first is returned.

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

Definition at line 591 of file stl_set.h.

## ◆ insert() [4/6]

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

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

Attempts to insert an element into the set.

Parameters

  __position | An iterator that serves as a hint as to where the element should be inserted.
  __x | Element to be inserted.

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

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

If a heterogeneous key __k matches a range of elements, an iterator to the first is returned.

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

Definition at line 596 of file stl_set.h.

## ◆ insert() [5/6]

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

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

Attempts to insert a list of elements into the set.

Parameters

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

Complexity similar to that of the range constructor.

Definition at line 639 of file stl_set.h.

## ◆ insert() [6/6]

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

std::pair< iterator, bool > std::set< _Key, _Compare, _Alloc >::insert | ( | value_type && | __x | ) |
| inline

Definition at line 543 of file stl_set.h.

## ◆ key_comp()

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

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

Returns the comparison object with which the set was constructed.

Definition at line 352 of file stl_set.h.

## ◆ lower_bound() [1/2]

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

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

Finds the beginning of a subsequence matching given key.

Parameters

  __x | Key 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 929 of file stl_set.h.

## ◆ lower_bound() [2/2]

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

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

Finds the beginning of a subsequence matching given key.

Parameters

  __x | Key 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 933 of file stl_set.h.

## ◆ max_size()

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

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

Returns the maximum size of the set.

Definition at line 449 of file stl_set.h.

## ◆ operator=() [1/3]

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

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

Set assignment operator.

Whether the allocator is copied depends on the allocator traits.

## ◆ operator=() [2/3]

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

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

Set list assignment operator.

Parameters

  __l | An initializer_list.

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

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

Definition at line 341 of file stl_set.h.

## ◆ operator=() [3/3]

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

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

Move assignment operator.

## ◆ rbegin()

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

reverse_iterator std::set< _Key, _Compare, _Alloc >::rbegin | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) iterator that points to the last element in the set. Iteration is done in descending order according to the keys.

Definition at line 387 of file stl_set.h.

## ◆ rend()

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

reverse_iterator std::set< _Key, _Compare, _Alloc >::rend | ( |  | ) | const
| inlinenoexcept

Returns a read-only (constant) reverse iterator that points to the last pair in the set. Iteration is done in descending order according to the keys.

Definition at line 396 of file stl_set.h.

## ◆ size()

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

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

Returns the size of the set.

Definition at line 444 of file stl_set.h.

## ◆ swap()

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

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

Swaps data with another set.

Parameters

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

This exchanges the elements between two sets 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(s1,s2) will feed to this function.

Whether the allocators are swapped depends on the allocator traits.

Definition at line 466 of file stl_set.h.

Referenced by std::swap().

## ◆ upper_bound() [1/2]

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

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

Finds the end of a subsequence matching given key.

Parameters

  __x | Key to be located.

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

Definition at line 959 of file stl_set.h.

## ◆ upper_bound() [2/2]

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

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

Finds the end of a subsequence matching given key.

Parameters

  __x | Key to be located.

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

Definition at line 963 of file stl_set.h.

## ◆ value_comp()

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

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

Returns the comparison object with which the set was constructed.

Definition at line 356 of file stl_set.h.

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

- stl_multiset.h
- stl_set.h