deduction guides for std::set

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Iterator invalidation

Member function table

Non-member function table

 

std::set

Member functions

set::set

set::~set

set::operator=

set::get_allocator

Iterators

set::beginset::cbegin (C++11)

set::endset::cend (C++11)

set::rbeginset::crbegin (C++11)

set::rendset::crend (C++11)

Capacity

set::empty

set::size

set::max_size

Modifiers

set::clear

set::insert

set::insert_range (C++23)

set::emplace (C++11)

set::emplace_hint (C++11)

set::erase

set::swap

set::extract (C++17)

set::merge (C++17)

Lookup

set::count

set::find

set::contains (C++20)

set::equal_range

set::lower_bound

set::upper_bound

Observers

set::key_comp

set::value_comp

Non-member functions

std::swap

erase_if (C++20)

operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)

Deduction guides(C++17)

 

Defined in header <set>
template<   class InputIt,   class Comp = std::less<typename std::iterator_traits<InputIt>::value_type>,   class Alloc = std::allocator<typename std::iterator_traits<InputIt>::value_type>> set( InputIt, InputIt, Comp = Comp(), Alloc = Alloc() )   -> set<typename std::iterator_traits<InputIt>::value_type, Comp, Alloc>;	(1)	(since C++17)
template<   class Key, class Comp = std::less<Key>,   class Alloc = std::allocator<Key> > set( std::initializer_list<Key>, Comp = Comp(), Alloc = Alloc() )   -> set<Key, Comp, Alloc>;	(2)	(since C++17)
template< class InputIt, class Alloc > set( InputIt, InputIt, Alloc )   -> set<typename std::iterator_traits<InputIt>::value_type,          std::less<typename std::iterator_traits<InputIt>::value_type>, Alloc>;	(3)	(since C++17)
template< class Key, class Alloc > set( std::initializer_list<Key>, Alloc )   -> set<Key, std::less<Key>, Alloc>;	(4)	(since C++17)
template< ranges::input_range R, class Compare = less<ranges::range_value_t<R>>,           class Alloc = std::allocator<ranges::range_value_t<R>> > set( std::from_range_t, R&&, Compare = Compare(), Alloc = Alloc() )   -> set<ranges::range_value_t<R>, Compare, Alloc>;	(5)	(since C++23)
template< ranges::input_range R, class Alloc > set( std::from_range_t, R&&, Alloc )   -> set<ranges::range_value_t<R>, std::less<ranges::range_value_t<R>>, Alloc>;	(6)	(since C++23)

1-4) These deduction guides are provided for set to allow deduction from an iterator range (overloads (1,3)) and std::initializer_list (overloads (2,4)).

5,6) These deduction guides are provided for set to allow deduction from a std::from_range_t tag and an input_range.

These overloads participate in overload resolution only if InputIt satisfies LegacyInputIterator, Alloc satisfies Allocator, and Comp does not satisfy Allocator.

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.

Notes

Feature-test macro	Value	Std	Comment
__cpp_lib_containers_ranges	202202L	(C++23)	Ranges-aware construction and insertion; overload (5,6)

Example

Run this code

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