deduction guides for std::unordered_multiset
std::unordered_multiset <unordered_set>
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,
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( 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>,
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>,
unordered_multiset( std::initializer_list <T>, typename /* see below */::size_type, Alloc )
unordered_multiset( std::initializer_list <T>, typename /* see below */::size_type,
Hash, Alloc )
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( std::from_range_t, R&&,
typename /* see below */::size_type, Alloc )
-> unordered_multiset<ranges::range_value_t <R>, hash<ranges::range_value_t <R>>,
unordered_multiset( std::from_range_t, R&&, Alloc )
-> unordered_multiset<ranges::range_value_t <R>, hash<ranges::range_value_t <R>>,
unordered_multiset( std::from_range_t, R&&,
typename /* see below */::size_type, Hash, Alloc )
-> unordered_multiset<ranges::range_value_t <R>, Hash,
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.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.
[edit] Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_containers_ranges |
202202L |
(C++23) | Ranges-aware construction and insertion; overloads (7-10) |
[edit] Example
#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()); }