deduction guides for std::unordered_multiset

 

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std::unordered_multiset

Member types
Member functions
unordered_multiset::unordered_multiset unordered_multiset::~unordered_multiset    unordered_multiset::operator= unordered_multiset::get_allocator Iterators unordered_multiset::beginunordered_multiset::cbegin unordered_multiset::endunordered_multiset::cend Capacity unordered_multiset::size unordered_multiset::max_size unordered_multiset::empty Modifiers unordered_multiset::clear unordered_multiset::insert unordered_multiset::insert_range (C++23) unordered_multiset::emplace unordered_multiset::emplace_hint unordered_multiset::erase unordered_multiset::swap unordered_multiset::extract (C++17) unordered_multiset::merge (C++17)	Lookup unordered_multiset::count unordered_multiset::find unordered_multiset::contains (C++20) unordered_multiset::equal_range Bucket interface unordered_multiset::begin(size_type)unordered_multiset::cbegin(size_type) unordered_multiset::end(size_type)unordered_multiset::cend(size_type) unordered_multiset::bucket_count unordered_multiset::max_bucket_count unordered_multiset::bucket_size unordered_multiset::bucket Hash policy unordered_multiset::load_factor unordered_multiset::max_load_factor unordered_multiset::rehash unordered_multiset::reserve Observers unordered_multiset::hash_function unordered_multiset::key_eq
Non-member functions
operator==operator!= (until C++20)	std::swap(std::unordered_multiset) erase_if(std::unordered_multiset) (C++20)
Deduction guides (C++17)

 

Defined in header <unordered_set>
template<     class InputIt,     class Hash = std::hash<typename std::iterator_traits<InputIt>::value_type>,     class Pred = std::equal_to<typename std::iterator_traits<InputIt>::value_type>,     class Alloc = std::allocator<typename std::iterator_traits<InputIt>::value_type> > unordered_multiset( InputIt, InputIt,                     typename /* see below */::size_type = /* see below */,                     Hash = Hash(), Pred = Pred(), Alloc = Alloc() )     -> unordered_multiset<typename std::iterator_traits<InputIt>::value_type,                           Hash, Pred, Alloc>;	(1)	(since C++17)
template< class T,           class Hash = std::hash<T>,           class Pred = std::equal_to<T>,           class Alloc = std::allocator<T> > unordered_multiset( std::initializer_list<T>,                     typename /* see below */::size_type = /* see below */,                     Hash = Hash(), Pred = Pred(), Alloc = Alloc() )     -> unordered_multiset<T, Hash, Pred, Alloc>;	(2)	(since C++17)
template< class InputIt, class Alloc > unordered_multiset( InputIt, InputIt, typename /* see below */::size_type, Alloc )     -> unordered_multiset<typename std::iterator_traits<InputIt>::value_type,                           std::hash<typename std::iterator_traits<InputIt>::value_type>,                           std::equal_to<typename std::iterator_traits<InputIt>::value_type>,                           Alloc>;	(3)	(since C++17)
template< class InputIt, class Hash, class Alloc > unordered_multiset( InputIt, InputIt, typename /* see below */::size_type, Hash, Alloc )     -> unordered_multiset<typename std::iterator_traits<InputIt>::value_type, Hash,                           std::equal_to<typename std::iterator_traits<InputIt>::value_type>,                           Alloc>;	(4)	(since C++17)
template< class T, class Alloc > unordered_multiset( std::initializer_list<T>, typename /* see below */::size_type, Alloc )     -> unordered_multiset<T, std::hash<T>, std::equal_to<T>, Alloc>;	(5)	(since C++17)
template< class T, class Hash, class Alloc > unordered_multiset( std::initializer_list<T>, typename /* see below */::size_type,                     Hash, Alloc )     -> unordered_multiset<T, Hash, std::equal_to<T>, Alloc>;	(6)	(since C++17)
template< ranges::input_range R,           class Hash = std::hash<ranges::range_value_t<R>>,           class Pred = std::equal_to<ranges::range_value_t<R>>,           class Alloc = std::allocator<ranges::range_value_t<R>> > unordered_multiset( std::from_range_t, R&&,                     typename /* see below */::size_type = /* see below */,                     Hash = Hash(), Pred = Pred(), Alloc = Alloc() )     -> unordered_multiset<ranges::range_value_t<R>, Hash, Pred, Alloc>;	(7)	(since C++23)
template< ranges::input_range R, class Alloc > unordered_multiset( std::from_range_t, R&&,                     typename /* see below */::size_type, Alloc )     -> unordered_multiset<ranges::range_value_t<R>, hash<ranges::range_value_t<R>>,                           std::equal_to<ranges::range_value_t<R>>, Alloc>;	(8)	(since C++23)
template< ranges::input_range R, class Alloc > unordered_multiset( std::from_range_t, R&&, Alloc )     -> unordered_multiset<ranges::range_value_t<R>, hash<ranges::range_value_t<R>>,                           std::equal_to<ranges::range_value_t<R>>, Alloc>;	(9)	(since C++23)
template< ranges::input_range R, class Hash, class Alloc > unordered_multiset( std::from_range_t, R&&,                     typename /* see below */::size_type, Hash, Alloc )     -> unordered_multiset<ranges::range_value_t<R>, Hash,                           std::equal_to<ranges::range_value_t<R>>, Alloc>;	(10)	(since C++23)

1-6) These deduction guides are provided for unordered_multiset to allow deduction from an iterator range (overloads (1,3,4)) and std::initializer_list (overloads (2,5,6)). This overload participates in overload resolution only if InputIt satisfies LegacyInputIterator, Alloc satisfies Allocator, neither Hash nor Pred satisfy Allocator, Hash is not an integral type.

7-10) These deduction guides are provided for unordered_multiset to allow deduction from a std::from_range_t tag and an input_range.

Note: the extent to which the library determines that a type does not satisfy LegacyInputIterator is unspecified, except that as a minimum integral types do not qualify as input iterators. Likewise, the extent to which it determines that a type does not satisfy Allocator is unspecified, except that as a minimum the member type Alloc::value_type must exist and the expression std::declval<Alloc&>().allocate(std::size_t{}) must be well-formed when treated as an unevaluated operand.

The size_type parameter type in these guides refers to the size_type member type of the type deduced by the deduction guide.

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_containers_ranges	202202L	(C++23)	Ranges-aware construction and insertion; overloads (7-10)

Example

Run this code

#include <unordered_set>
 
int main()
{
    // guide #2 deduces std::unordered_multiset<int>
    std::unordered_multiset s = {1, 2, 3, 4};
 
    // guide #1 deduces std::unordered_multiset<int>
    std::unordered_multiset s2(s.begin(), s.end());
}