NAME

std::unordered_set::equal_range - std::unordered_set::equal_range

Synopsis

std::pair<iterator,iterator> equal_range( const Key& key ); (1) (since C++11)
std::pair<const_iterator,const_iterator> equal_range( const Key& (2) (since C++11)
key ) const;
template< class K > (3) (since C++20)
std::pair<iterator,iterator> equal_range( const K& x );
template< class K >
std::pair<const_iterator,const_iterator> equal_range( const K& x ) (4) (since C++20)
const;

1,2) Returns a range containing all elements with key key in the container. The
range is defined by two iterators, the first pointing to the first element of the
wanted range and the second pointing past the last element of the range.
3,4) Returns a range containing all elements in the container with key equivalent to
x. This overload participates in overload resolution only if Hash::is_transparent
and KeyEqual::is_transparent are valid and each denotes a type. This assumes that
such Hash is callable with both K and Key type, and that the KeyEqual is
transparent, which, together, allows calling this function without constructing an
instance of Key.

Parameters

key - key value to compare the elements to
x - a value of any type that can be transparently compared with a key

Return value

std::pair containing a pair of iterators defining the wanted range. If there are no
such elements, past-the-end (see end()) iterators are returned as both elements of
the pair.

Complexity

Average case linear in the number of elements with the key key, worst case linear in
the size of the container.

Notes

Feature-test macro: __cpp_lib_generic_unordered_lookup (for overloads (3,4))

Example

This section is incomplete
Reason: no example