deduction guides for std::deque

 

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Containers library

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array (C++11)

vector

vector<bool>

deque

forward_list (C++11)

list

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unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

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stack

queue

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span (C++20)

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std::deque

Member types

Member functions

deque::deque

deque::~deque

deque::operator=

deque::assign

deque::assign_range (C++23)

deque::get_allocator

Element access

deque::at

deque::operator[]

deque::front

deque::back

Iterators

deque::begindeque::cbegin (C++11)

deque::enddeque::cend (C++11)

deque::rbegindeque::crbegin (C++11)

deque::renddeque::crend (C++11)

Capacity

deque::empty

deque::size

deque::max_size

deque::shrink_to_fit (DR*)

Modifiers

deque::clear

deque::insert

deque::insert_range (C++23)

deque::emplace

deque::erase

deque::push_front

deque::emplace_front (C++11)

deque::prepend_range (C++23)

deque::pop_front

deque::push_back

deque::emplace_back (C++11)

deque::append_range (C++23)

deque::pop_back

deque::resize

deque::swap

Non-member functions

std::swap

eraseerase_if (C++20)(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 <deque>
template< class InputIt,           class Alloc = std::allocator<               typename std::iterator_traits<InputIt>::value_type> > deque( InputIt, InputIt, Alloc = Alloc() )   -> deque<typename std::iterator_traits<InputIt>::value_type, Alloc>;	(1)	(since C++17)
template< ranges::input_range R,           class Alloc = std::allocator<ranges::range_value_t<R>> > deque( std::from_range_t, R&&, Alloc = Alloc() )   -> deque<ranges::range_value_t<R>, Alloc>;	(2)	(since C++23)

1) This deduction guide is provided for deque to allow deduction from an iterator range. This overload participates in overload resolution only if InputIt satisfies LegacyInputIterator and Alloc satisfies Allocator.

2) This deduction guide is provided for deque 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.

Notes

Feature-test macro	Value	Std	Comment
__cpp_lib_containers_ranges	202202L	(C++23)	Ranges-aware construction and insertion; overload (2)

Example

Run this code

#include <deque>
#include <vector>
 
int main()
{
    std::vector<int> v = {1, 2, 3, 4};
 
    // uses explicit deduction guide to deduce std::deque<int>
    std::deque x(v.begin(), v.end());
 
    // deduces std::deque<std::vector<int>::iterator>
    // first phase of overload resolution for list-initialization selects the candidate
    // synthesized from the initializer-list constructor; second phase is not performed
    // and deduction guide has no effect
    std::deque y{v.begin(), v.end()};
}