deduction guides for std::queue

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

span (C++20)

std::queue

Member functions

queue::queue

queue::~queue

queue::operator=

Element access

queue::front

queue::back

Capacity

queue::empty

queue::size

Modifiers

queue::push

queue::emplace

queue::pop

queue::swap

Deduction guides(C++17)

Defined in header <queue>
template<class Container> queue(Container) -> queue<typename Container::value_type, Container>;	(1)	(since C++17)
template<class Container, class Allocator> queue(Container, Allocator) -> queue<typename Container::value_type, Container>;	(2)	(since C++17)

These deduction guides are provided for queue to allow deduction from underlying container type. This overload only participates in overload resolution if Alloc satisfies Allocator, and Container does not satisfy Allocator and, for overload (2), if std::uses_allocator_v<Container, Allocator> is true

Note: the extent to which the library determines that a type does not satisfy InputIterator 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.

Example

Run this code

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