View source for Template:cpp/container/set deduction guides

{{title|deduction guides for {{tt|std::{{{1}}}}}}}
{{cpp/container/{{{1|}}}/navbar}}
{{dcl begin}}
{{dcl header|set}}
{{dcl|since=c++17|num=1|1=
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>>
{{{1}}}( InputIt, InputIt, Comp = Comp(), Alloc = Alloc() )
    -> {{{1}}}<typename std::iterator_traits<InputIt>::value_type, Comp, Alloc>;
}}
{{dcl|since=c++17|num=2|1=
template<
    class Key, class Comp = std::less<Key>,
    class Alloc = std::allocator<Key> >
{{{1}}}( std::initializer_list<Key>, Comp = Comp(), Alloc = Alloc() )
    -> {{{1}}}<Key, Comp, Alloc>;
}}
{{dcl|since=c++17|num=3|1=
template< class InputIt, class Alloc >
{{{1}}}( InputIt, InputIt, Alloc )
    -> {{{1}}}<typename std::iterator_traits<InputIt>::value_type,
       {{space as|{{{1}}}}} std::less<typename std::iterator_traits<InputIt>::value_type>, Alloc>;
}}
{{dcl|since=c++17|num=4|1=
template< class Key, class Alloc >
{{{1}}}( std::initializer_list<Key>, Alloc )
    -> {{{1}}}<Key, std::less<Key>, Alloc>;
}}
{{dcl|since=c++23|num=5|1=
template< ranges::input_range R, class Compare = less<ranges::range_value_t<R>>,
          class Alloc = std::allocator<ranges::range_value_t<R>> >
{{{1}}}( std::from_range_t, R&&, Compare = Compare(), Alloc = Alloc() )
    -> {{{1}}}<ranges::range_value_t<R>, Compare, Alloc>;
}}
{{dcl|since=c++23|num=6|1=
template< ranges::input_range R, class Alloc >
{{{1}}}( std::from_range_t, R&&, Alloc )
    -> {{{1}}}<ranges::range_value_t<R>, std::less<ranges::range_value_t<R>>, Alloc>;
}}
{{dcl end}}

@1-4@ These [[cpp/language/class template argument deduction|deduction guides]] are provided for {{tt|{{{1}}}}} to allow deduction from an iterator range (overloads {{v|1,3}}) and {{lc|std::initializer_list}} (overloads {{v|2,4}}).

@5,6@ These deduction guides are provided for {{tt|{{{1}}}}} to allow deduction from a {{ltt|cpp/ranges/from_range|std::from_range_t}} tag and an {{lconcept|input_range}}.

{{cpp/enable_if|{{tt|InputIt}} satisfies {{named req|InputIterator}}, {{tt|Alloc}} satisfies {{named req|Allocator}}, and {{tt|Comp}} does not satisfy {{named req|Allocator}}|plural=yes}}.

{{cpp/container/inputit_allocator_detection}}

===Notes===
{{feature test macro|__cpp_lib_containers_ranges|[[cpp/ranges/to#container compatible range|Ranges-aware]] construction and insertion; overload {{v|5,6}}|value=202202L|std=C++23}}

===Example===
{{example
|code=
#include <set>

int main()
{
    // guide #2 deduces std::{{{1}}}<int>
    std::{{{1}}} s = {1, 2, 3, 4};

    // guide #1 deduces std::{{{1}}}<int>
    std::{{{1}}} s2(s.begin(), s.end());
}
}}