.TH "std::unordered_set< _Value, _Hash, _Pred, _Alloc >" 3cxx "Tue Feb 2 2021" "libstdc++" \" -*- nroff -*-
.ad l
.nh
.SH NAME
std::unordered_set< _Value, _Hash, _Pred, _Alloc > \- A standard container composed of unique keys (containing at most one of each key value) in which the elements' keys are the elements themselves\&.  

.SH SYNOPSIS
.br
.PP
.SS "Public Types"

.in +1c
.ti -1c
.RI "typedef _Hashtable::allocator_type \fBallocator_type\fP"
.br
.ti -1c
.RI "typedef _Hashtable::const_iterator \fBconst_iterator\fP"
.br
.ti -1c
.RI "typedef _Hashtable::const_local_iterator \fBconst_local_iterator\fP"
.br
.ti -1c
.RI "typedef _Hashtable::const_pointer \fBconst_pointer\fP"
.br
.ti -1c
.RI "typedef _Hashtable::const_reference \fBconst_reference\fP"
.br
.ti -1c
.RI "typedef _Hashtable::difference_type \fBdifference_type\fP"
.br
.ti -1c
.RI "typedef _Hashtable::hasher \fBhasher\fP"
.br
.ti -1c
.RI "typedef _Hashtable::iterator \fBiterator\fP"
.br
.ti -1c
.RI "typedef _Hashtable::key_equal \fBkey_equal\fP"
.br
.ti -1c
.RI "typedef _Hashtable::key_type \fBkey_type\fP"
.br
.RI "Public typedefs\&. "
.ti -1c
.RI "typedef _Hashtable::local_iterator \fBlocal_iterator\fP"
.br
.ti -1c
.RI "typedef _Hashtable::pointer \fBpointer\fP"
.br
.RI "Iterator-related typedefs\&. "
.ti -1c
.RI "typedef _Hashtable::reference \fBreference\fP"
.br
.ti -1c
.RI "typedef _Hashtable::size_type \fBsize_type\fP"
.br
.ti -1c
.RI "typedef _Hashtable::value_type \fBvalue_type\fP"
.br
.in -1c
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "\fBunordered_set\fP ()=default"
.br
.RI "Default constructor\&. "
.ti -1c
.RI "template<typename _InputIterator > \fBunordered_set\fP (_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type &__a)"
.br
.ti -1c
.RI "template<typename _InputIterator > \fBunordered_set\fP (_InputIterator __first, _InputIterator __last, size_type __n, const hasher &__hf, const allocator_type &__a)"
.br
.ti -1c
.RI "template<typename _InputIterator > \fBunordered_set\fP (_InputIterator __first, _InputIterator __last, size_type __n=0, const hasher &__hf=hasher(), const key_equal &__eql=key_equal(), const allocator_type &__a=allocator_type())"
.br
.RI "Builds an unordered_set from a range\&. "
.ti -1c
.RI "\fBunordered_set\fP (const allocator_type &__a)"
.br
.RI "Creates an unordered_set with no elements\&. "
.ti -1c
.RI "\fBunordered_set\fP (const \fBunordered_set\fP &)=default"
.br
.RI "Copy constructor\&. "
.ti -1c
.RI "\fBunordered_set\fP (const \fBunordered_set\fP &__uset, const allocator_type &__a)"
.br
.ti -1c
.RI "\fBunordered_set\fP (\fBinitializer_list\fP< value_type > __l, size_type __n, const allocator_type &__a)"
.br
.ti -1c
.RI "\fBunordered_set\fP (\fBinitializer_list\fP< value_type > __l, size_type __n, const hasher &__hf, const allocator_type &__a)"
.br
.ti -1c
.RI "\fBunordered_set\fP (\fBinitializer_list\fP< value_type > __l, size_type __n=0, const hasher &__hf=hasher(), const key_equal &__eql=key_equal(), const allocator_type &__a=allocator_type())"
.br
.RI "Builds an unordered_set from an initializer_list\&. "
.ti -1c
.RI "\fBunordered_set\fP (size_type __n, const allocator_type &__a)"
.br
.ti -1c
.RI "\fBunordered_set\fP (size_type __n, const hasher &__hf, const allocator_type &__a)"
.br
.ti -1c
.RI "\fBunordered_set\fP (size_type __n, const hasher &__hf=hasher(), const key_equal &__eql=key_equal(), const allocator_type &__a=allocator_type())"
.br
.RI "Default constructor creates no elements\&. "
.ti -1c
.RI "\fBunordered_set\fP (\fBunordered_set\fP &&)=default"
.br
.RI "Move constructor\&. "
.ti -1c
.RI "\fBunordered_set\fP (\fBunordered_set\fP &&__uset, const allocator_type &__a)"
.br
.ti -1c
.RI "const_iterator \fBbegin\fP () const noexcept"
.br
.ti -1c
.RI "iterator \fBbegin\fP () noexcept"
.br
.ti -1c
.RI "local_iterator \fBbegin\fP (size_type __n)"
.br
.RI "Returns a read-only (constant) iterator pointing to the first bucket element\&. "
.ti -1c
.RI "const_local_iterator \fBbegin\fP (size_type __n) const"
.br
.ti -1c
.RI "size_type \fBbucket\fP (const \fBkey_type\fP &__key) const"
.br
.ti -1c
.RI "size_type \fBbucket_count\fP () const noexcept"
.br
.RI "Returns the number of buckets of the unordered_set\&. "
.ti -1c
.RI "size_type \fBbucket_size\fP (size_type __n) const"
.br
.ti -1c
.RI "const_iterator \fBcbegin\fP () const noexcept"
.br
.ti -1c
.RI "const_local_iterator \fBcbegin\fP (size_type __n) const"
.br
.ti -1c
.RI "const_iterator \fBcend\fP () const noexcept"
.br
.ti -1c
.RI "const_local_iterator \fBcend\fP (size_type __n) const"
.br
.ti -1c
.RI "void \fBclear\fP () noexcept"
.br
.ti -1c
.RI "size_type \fBcount\fP (const \fBkey_type\fP &__x) const"
.br
.RI "Finds the number of elements\&. "
.ti -1c
.RI "template<typename\&.\&.\&. _Args> \fBstd::pair\fP< iterator, bool > \fBemplace\fP (_Args &&\&.\&.\&. __args)"
.br
.RI "Attempts to build and insert an element into the unordered_set\&. "
.ti -1c
.RI "template<typename\&.\&.\&. _Args> iterator \fBemplace_hint\fP (const_iterator __pos, _Args &&\&.\&.\&. __args)"
.br
.RI "Attempts to insert an element into the unordered_set\&. "
.ti -1c
.RI "bool \fBempty\fP () const noexcept"
.br
.RI "Returns true if the unordered_set is empty\&. "
.ti -1c
.RI "const_iterator \fBend\fP () const noexcept"
.br
.ti -1c
.RI "iterator \fBend\fP () noexcept"
.br
.ti -1c
.RI "local_iterator \fBend\fP (size_type __n)"
.br
.RI "Returns a read-only (constant) iterator pointing to one past the last bucket elements\&. "
.ti -1c
.RI "const_local_iterator \fBend\fP (size_type __n) const"
.br
.ti -1c
.RI "\fBstd::pair\fP< iterator, iterator > \fBequal_range\fP (const \fBkey_type\fP &__x)"
.br
.RI "Finds a subsequence matching given key\&. "
.ti -1c
.RI "\fBstd::pair\fP< const_iterator, const_iterator > \fBequal_range\fP (const \fBkey_type\fP &__x) const"
.br
.ti -1c
.RI "size_type \fBerase\fP (const \fBkey_type\fP &__x)"
.br
.RI "Erases elements according to the provided key\&. "
.ti -1c
.RI "iterator \fBerase\fP (const_iterator __first, const_iterator __last)"
.br
.RI "Erases a [__first,__last) range of elements from an unordered_set\&. "
.ti -1c
.RI "iterator \fBerase\fP (const_iterator __position)"
.br
.RI "Erases an element from an unordered_set\&. "
.ti -1c
.RI "iterator \fBerase\fP (iterator __position)"
.br
.ti -1c
.RI "iterator \fBfind\fP (const \fBkey_type\fP &__x)"
.br
.RI "Tries to locate an element in an unordered_set\&. "
.ti -1c
.RI "const_iterator \fBfind\fP (const \fBkey_type\fP &__x) const"
.br
.ti -1c
.RI "allocator_type \fBget_allocator\fP () const noexcept"
.br
.RI "Returns the allocator object used by the unordered_set\&. "
.ti -1c
.RI "hasher \fBhash_function\fP () const"
.br
.RI "Returns the hash functor object with which the unordered_set was constructed\&. "
.ti -1c
.RI "template<typename _InputIterator > void \fBinsert\fP (_InputIterator __first, _InputIterator __last)"
.br
.RI "A template function that attempts to insert a range of elements\&. "
.ti -1c
.RI "\fBstd::pair\fP< iterator, bool > \fBinsert\fP (const value_type &__x)"
.br
.RI "Attempts to insert an element into the unordered_set\&. "
.ti -1c
.RI "iterator \fBinsert\fP (const_iterator __hint, const value_type &__x)"
.br
.RI "Attempts to insert an element into the unordered_set\&. "
.ti -1c
.RI "iterator \fBinsert\fP (const_iterator __hint, value_type &&__x)"
.br
.ti -1c
.RI "void \fBinsert\fP (\fBinitializer_list\fP< value_type > __l)"
.br
.RI "Attempts to insert a list of elements into the unordered_set\&. "
.ti -1c
.RI "\fBstd::pair\fP< iterator, bool > \fBinsert\fP (value_type &&__x)"
.br
.ti -1c
.RI "key_equal \fBkey_eq\fP () const"
.br
.RI "Returns the key comparison object with which the unordered_set was constructed\&. "
.ti -1c
.RI "float \fBload_factor\fP () const noexcept"
.br
.RI "Returns the average number of elements per bucket\&. "
.ti -1c
.RI "size_type \fBmax_bucket_count\fP () const noexcept"
.br
.RI "Returns the maximum number of buckets of the unordered_set\&. "
.ti -1c
.RI "float \fBmax_load_factor\fP () const noexcept"
.br
.RI "Returns a positive number that the unordered_set tries to keep the load factor less than or equal to\&. "
.ti -1c
.RI "void \fBmax_load_factor\fP (float __z)"
.br
.RI "Change the unordered_set maximum load factor\&. "
.ti -1c
.RI "size_type \fBmax_size\fP () const noexcept"
.br
.RI "Returns the maximum size of the unordered_set\&. "
.ti -1c
.RI "\fBunordered_set\fP & \fBoperator=\fP (const \fBunordered_set\fP &)=default"
.br
.RI "Copy assignment operator\&. "
.ti -1c
.RI "\fBunordered_set\fP & \fBoperator=\fP (\fBinitializer_list\fP< value_type > __l)"
.br
.RI "Unordered_set list assignment operator\&. "
.ti -1c
.RI "\fBunordered_set\fP & \fBoperator=\fP (\fBunordered_set\fP &&)=default"
.br
.RI "Move assignment operator\&. "
.ti -1c
.RI "void \fBrehash\fP (size_type __n)"
.br
.RI "May rehash the unordered_set\&. "
.ti -1c
.RI "void \fBreserve\fP (size_type __n)"
.br
.RI "Prepare the unordered_set for a specified number of elements\&. "
.ti -1c
.RI "size_type \fBsize\fP () const noexcept"
.br
.RI "Returns the size of the unordered_set\&. "
.ti -1c
.RI "void \fBswap\fP (\fBunordered_set\fP &__x) noexcept(noexcept(_M_h\&.swap(__x\&._M_h)))"
.br
.RI "Swaps data with another unordered_set\&. "
.in -1c
.SS "Friends"

.in +1c
.ti -1c
.RI "template<typename _Value1 , typename _Hash1 , typename _Pred1 , typename _Alloc1 > bool \fBoperator==\fP (const \fBunordered_set\fP< _Value1, _Hash1, _Pred1, _Alloc1 > &, const \fBunordered_set\fP< _Value1, _Hash1, _Pred1, _Alloc1 > &)"
.br
.in -1c
.SH "Detailed Description"
.PP 

.SS "template<typename _Value, typename _Hash = hash<_Value>, typename _Pred = equal_to<_Value>, typename _Alloc = allocator<_Value>>
.br
class std::unordered_set< _Value, _Hash, _Pred, _Alloc >"
A standard container composed of unique keys (containing at most one of each key value) in which the elements' keys are the elements themselves\&. 


.PP
\fBTemplate Parameters\fP
.RS 4
\fI_Value\fP Type of key objects\&. 
.br
\fI_Hash\fP Hashing function object type, defaults to hash<_Value>\&.
.br
\fI_Pred\fP Predicate function object type, defaults to equal_to<_Value>\&.
.br
\fI_Alloc\fP Allocator type, defaults to allocator<_Key>\&.
.RE
.PP
Meets the requirements of a \fCcontainer\fP, and \fCunordered associative container\fP
.PP
Base is _Hashtable, dispatched at compile time via template alias __uset_hashtable\&. 
.PP
Definition at line 97 of file unordered_set\&.h\&.
.SH "Member Typedef Documentation"
.PP 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> typedef _Hashtable::key_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBkey_type\fP"

.PP
Public typedefs\&. 
.PP
Definition at line 106 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> typedef _Hashtable::pointer \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBpointer\fP"

.PP
Iterator-related typedefs\&. 
.PP
Definition at line 115 of file unordered_set\&.h\&.
.SH "Constructor & Destructor Documentation"
.PP 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP ()\fC [default]\fP"

.PP
Default constructor\&. 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP (size_type __n, const hasher & __hf = \fChasher()\fP, const key_equal & __eql = \fCkey_equal()\fP, const allocator_type & __a = \fCallocator_type()\fP)\fC [inline]\fP, \fC [explicit]\fP"

.PP
Default constructor creates no elements\&. 
.PP
\fBParameters\fP
.RS 4
\fI__n\fP Minimal initial number of buckets\&. 
.br
\fI__hf\fP A hash functor\&. 
.br
\fI__eql\fP A key equality functor\&. 
.br
\fI__a\fP An allocator object\&. 
.RE
.PP

.PP
Definition at line 145 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> template<typename _InputIterator > \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP (_InputIterator __first, _InputIterator __last, size_type __n = \fC0\fP, const hasher & __hf = \fChasher()\fP, const key_equal & __eql = \fCkey_equal()\fP, const allocator_type & __a = \fCallocator_type()\fP)\fC [inline]\fP"

.PP
Builds an unordered_set from a range\&. 
.PP
\fBParameters\fP
.RS 4
\fI__first\fP An input iterator\&. 
.br
\fI__last\fP An input iterator\&. 
.br
\fI__n\fP Minimal initial number of buckets\&. 
.br
\fI__hf\fP A hash functor\&. 
.br
\fI__eql\fP A key equality functor\&. 
.br
\fI__a\fP An allocator object\&.
.RE
.PP
Create an unordered_set consisting of copies of the elements from [__first,__last)\&. This is linear in N (where N is distance(__first,__last))\&. 
.PP
Definition at line 166 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP (const \fBunordered_set\fP< _Value, _Hash, _Pred, _Alloc > &)\fC [default]\fP"

.PP
Copy constructor\&. 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP (\fBunordered_set\fP< _Value, _Hash, _Pred, _Alloc > &&)\fC [default]\fP"

.PP
Move constructor\&. 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP (const allocator_type & __a)\fC [inline]\fP, \fC [explicit]\fP"

.PP
Creates an unordered_set with no elements\&. 
.PP
\fBParameters\fP
.RS 4
\fI__a\fP An allocator object\&. 
.RE
.PP

.PP
Definition at line 185 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::\fBunordered_set\fP (\fBinitializer_list\fP< value_type > __l, size_type __n = \fC0\fP, const hasher & __hf = \fChasher()\fP, const key_equal & __eql = \fCkey_equal()\fP, const allocator_type & __a = \fCallocator_type()\fP)\fC [inline]\fP"

.PP
Builds an unordered_set from an initializer_list\&. 
.PP
\fBParameters\fP
.RS 4
\fI__l\fP An initializer_list\&. 
.br
\fI__n\fP Minimal initial number of buckets\&. 
.br
\fI__hf\fP A hash functor\&. 
.br
\fI__eql\fP A key equality functor\&. 
.br
\fI__a\fP An allocator object\&.
.RE
.PP
Create an unordered_set consisting of copies of the elements in the list\&. This is linear in N (where N is \fI__l\&.size()\fP)\&. 
.PP
Definition at line 220 of file unordered_set\&.h\&.
.SH "Member Function Documentation"
.PP 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::begin ()\fC [inline]\fP, \fC [noexcept]\fP"
Returns a read-only (constant) iterator that points to the first element in the unordered_set\&. 
.PP
Definition at line 319 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> local_iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::begin (size_type __n)\fC [inline]\fP"

.PP
Returns a read-only (constant) iterator pointing to the first bucket element\&. 
.PP
\fBParameters\fP
.RS 4
\fI__n\fP The bucket index\&. 
.RE
.PP
\fBReturns\fP
.RS 4
A read-only local iterator\&. 
.RE
.PP

.PP
Definition at line 726 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> size_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::bucket_count () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns the number of buckets of the unordered_set\&. 
.PP
Definition at line 692 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> const_iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::cbegin () const\fC [inline]\fP, \fC [noexcept]\fP"
Returns a read-only (constant) iterator that points to the first element in the unordered_set\&. 
.PP
Definition at line 346 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> const_iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::cend () const\fC [inline]\fP, \fC [noexcept]\fP"
Returns a read-only (constant) iterator that points one past the last element in the unordered_set\&. 
.PP
Definition at line 354 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::clear ()\fC [inline]\fP, \fC [noexcept]\fP"
Erases all elements in an unordered_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\&. 
.PP
Definition at line 572 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> size_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::count (const \fBkey_type\fP & __x) const\fC [inline]\fP"

.PP
Finds the number of elements\&. 
.PP
\fBParameters\fP
.RS 4
\fI__x\fP Element to located\&. 
.RE
.PP
\fBReturns\fP
.RS 4
Number of elements with specified key\&.
.RE
.PP
This function only makes sense for unordered_multisets; for unordered_set the result will either be 0 (not present) or 1 (present)\&. 
.PP
Definition at line 667 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> template<typename\&.\&.\&. _Args> \fBstd::pair\fP<iterator, bool> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::emplace (_Args &&\&.\&.\&. __args)\fC [inline]\fP"

.PP
Attempts to build and insert an element into the unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__args\fP Arguments used to generate an element\&. 
.RE
.PP
\fBReturns\fP
.RS 4
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\&.
.RE
.PP
This function attempts to build and insert an element into the unordered_set\&. An unordered_set relies on unique keys and thus an element is only inserted if it is not already present in the unordered_set\&.
.PP
Insertion requires amortized constant time\&. 
.PP
Definition at line 376 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> template<typename\&.\&.\&. _Args> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::emplace_hint (const_iterator __pos, _Args &&\&.\&.\&. __args)\fC [inline]\fP"

.PP
Attempts to insert an element into the unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__pos\fP An iterator that serves as a hint as to where the element should be inserted\&. 
.br
\fI__args\fP Arguments used to generate the element to be inserted\&. 
.RE
.PP
\fBReturns\fP
.RS 4
An iterator that points to the element with key equivalent to the one generated from \fI__args\fP (may or may not be the element itself)\&.
.RE
.PP
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\&.
.PP
For more on \fIhinting\fP, see: https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
.PP
Insertion requires amortized constant time\&. 
.PP
Definition at line 402 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> bool \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::empty () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns true if the unordered_set is empty\&. 
.PP
Definition at line 298 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::end ()\fC [inline]\fP, \fC [noexcept]\fP"
Returns a read-only (constant) iterator that points one past the last element in the unordered_set\&. 
.PP
Definition at line 333 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> local_iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::end (size_type __n)\fC [inline]\fP"

.PP
Returns a read-only (constant) iterator pointing to one past the last bucket elements\&. 
.PP
\fBParameters\fP
.RS 4
\fI__n\fP The bucket index\&. 
.RE
.PP
\fBReturns\fP
.RS 4
A read-only local iterator\&. 
.RE
.PP

.PP
Definition at line 746 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::pair\fP<iterator, iterator> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::equal_range (const \fBkey_type\fP & __x)\fC [inline]\fP"

.PP
Finds a subsequence matching given key\&. 
.PP
\fBParameters\fP
.RS 4
\fI__x\fP Key to be located\&. 
.RE
.PP
\fBReturns\fP
.RS 4
Pair of iterators that possibly points to the subsequence matching given key\&.
.RE
.PP
This function probably only makes sense for multisets\&. 
.PP
Definition at line 680 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> size_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::erase (const \fBkey_type\fP & __x)\fC [inline]\fP"

.PP
Erases elements according to the provided key\&. 
.PP
\fBParameters\fP
.RS 4
\fI__x\fP Key of element to be erased\&. 
.RE
.PP
\fBReturns\fP
.RS 4
The number of elements erased\&.
.RE
.PP
This function erases all the elements located by the given key from an unordered_set\&. For an unordered_set the result of this function can only be 0 (not present) or 1 (present)\&. 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\&. 
.PP
Definition at line 544 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::erase (const_iterator __first, const_iterator __last)\fC [inline]\fP"

.PP
Erases a [__first,__last) range of elements from an unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__first\fP Iterator pointing to the start of the range to be erased\&. 
.br
\fI__last\fP Iterator pointing to the end of the range to be erased\&. 
.RE
.PP
\fBReturns\fP
.RS 4
The iterator \fI__last\fP\&.
.RE
.PP
This function erases a sequence of elements from an unordered_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\&. 
.PP
Definition at line 562 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::erase (const_iterator __position)\fC [inline]\fP"

.PP
Erases an element from an unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__position\fP An iterator pointing to the element to be erased\&. 
.RE
.PP
\fBReturns\fP
.RS 4
An iterator pointing to the element immediately following \fI__position\fP prior to the element being erased\&. If no such element exists, end() is returned\&.
.RE
.PP
This function erases an element, pointed to by the given iterator, from an unordered_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\&. 
.PP
Definition at line 522 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::find (const \fBkey_type\fP & __x)\fC [inline]\fP"

.PP
Tries to locate an element in an unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__x\fP Element to be located\&. 
.RE
.PP
\fBReturns\fP
.RS 4
Iterator pointing to sought-after element, or end() if not found\&.
.RE
.PP
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 ( \fCend()\fP ) iterator\&. 
.PP
Definition at line 649 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> allocator_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::get_allocator () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns the allocator object used by the unordered_set\&. 
.PP
Definition at line 291 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> hasher \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::hash_function () const\fC [inline]\fP"

.PP
Returns the hash functor object with which the unordered_set was constructed\&. 
.PP
Definition at line 625 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> template<typename _InputIterator > void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::insert (_InputIterator __first, _InputIterator __last)\fC [inline]\fP"

.PP
A template function that attempts to insert a range of elements\&. 
.PP
\fBParameters\fP
.RS 4
\fI__first\fP Iterator pointing to the start of the range to be inserted\&. 
.br
\fI__last\fP Iterator pointing to the end of the range\&.
.RE
.PP
Complexity similar to that of the range constructor\&. 
.PP
Definition at line 468 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBstd::pair\fP<iterator, bool> \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::insert (const value_type & __x)\fC [inline]\fP"

.PP
Attempts to insert an element into the unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__x\fP Element to be inserted\&. 
.RE
.PP
\fBReturns\fP
.RS 4
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\&.
.RE
.PP
This function attempts to insert an element into the unordered_set\&. An unordered_set relies on unique keys and thus an element is only inserted if it is not already present in the unordered_set\&.
.PP
Insertion requires amortized constant time\&. 
.PP
Definition at line 420 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> iterator \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::insert (const_iterator __hint, const value_type & __x)\fC [inline]\fP"

.PP
Attempts to insert an element into the unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__hint\fP An iterator that serves as a hint as to where the element should be inserted\&. 
.br
\fI__x\fP Element to be inserted\&. 
.RE
.PP
\fBReturns\fP
.RS 4
An iterator that points to the element with key of \fI__x\fP (may or may not be the element passed in)\&.
.RE
.PP
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\&.
.PP
For more on \fIhinting\fP, see: https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
.PP
Insertion requires amortized constant\&. 
.PP
Definition at line 449 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::insert (\fBinitializer_list\fP< value_type > __l)\fC [inline]\fP"

.PP
Attempts to insert a list of elements into the unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__l\fP A std::initializer_list<value_type> of elements to be inserted\&.
.RE
.PP
Complexity similar to that of the range constructor\&. 
.PP
Definition at line 479 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> key_equal \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::key_eq () const\fC [inline]\fP"

.PP
Returns the key comparison object with which the unordered_set was constructed\&. 
.PP
Definition at line 631 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> float \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::load_factor () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns the average number of elements per bucket\&. 
.PP
Definition at line 762 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> size_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::max_bucket_count () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns the maximum number of buckets of the unordered_set\&. 
.PP
Definition at line 697 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> float \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::max_load_factor () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns a positive number that the unordered_set tries to keep the load factor less than or equal to\&. 
.PP
Definition at line 768 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::max_load_factor (float __z)\fC [inline]\fP"

.PP
Change the unordered_set maximum load factor\&. 
.PP
\fBParameters\fP
.RS 4
\fI__z\fP The new maximum load factor\&. 
.RE
.PP

.PP
Definition at line 776 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> size_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::max_size () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns the maximum size of the unordered_set\&. 
.PP
Definition at line 308 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBunordered_set\fP& \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::operator= (const \fBunordered_set\fP< _Value, _Hash, _Pred, _Alloc > &)\fC [default]\fP"

.PP
Copy assignment operator\&. 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBunordered_set\fP& \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::operator= (\fBinitializer_list\fP< value_type > __l)\fC [inline]\fP"

.PP
Unordered_set list assignment operator\&. 
.PP
\fBParameters\fP
.RS 4
\fI__l\fP An initializer_list\&.
.RE
.PP
This function fills an unordered_set with copies of the elements in the initializer list \fI__l\fP\&.
.PP
Note that the assignment completely changes the unordered_set and that the resulting unordered_set's size is the same as the number of elements assigned\&. 
.PP
Definition at line 283 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> \fBunordered_set\fP& \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::operator= (\fBunordered_set\fP< _Value, _Hash, _Pred, _Alloc > &&)\fC [default]\fP"

.PP
Move assignment operator\&. 
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::rehash (size_type __n)\fC [inline]\fP"

.PP
May rehash the unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__n\fP The new number of buckets\&.
.RE
.PP
Rehash will occur only if the new number of buckets respect the unordered_set maximum load factor\&. 
.PP
Definition at line 787 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::reserve (size_type __n)\fC [inline]\fP"

.PP
Prepare the unordered_set for a specified number of elements\&. 
.PP
\fBParameters\fP
.RS 4
\fI__n\fP Number of elements required\&.
.RE
.PP
Same as rehash(ceil(n / max_load_factor()))\&. 
.PP
Definition at line 798 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> size_type \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::size () const\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Returns the size of the unordered_set\&. 
.PP
Definition at line 303 of file unordered_set\&.h\&.
.SS "template<typename _Value , typename _Hash  = hash<_Value>, typename _Pred  = equal_to<_Value>, typename _Alloc  = allocator<_Value>> void \fBstd::unordered_set\fP< _Value, _Hash, _Pred, _Alloc >::swap (\fBunordered_set\fP< _Value, _Hash, _Pred, _Alloc > & __x)\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Swaps data with another unordered_set\&. 
.PP
\fBParameters\fP
.RS 4
\fI__x\fP An unordered_set of the same element and allocator types\&.
.RE
.PP
This exchanges the elements between two sets in constant time\&. Note that the global std::swap() function is specialized such that std::swap(s1,s2) will feed to this function\&. 
.PP
Definition at line 585 of file unordered_set\&.h\&.

.SH "Author"
.PP 
Generated automatically by Doxygen for libstdc++ from the source code\&.