std::queue::emplace

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)

template< class... Args > void emplace( Args&&... args );		(since C++11) (until C++17)
template< class... Args > decltype(auto) emplace( Args&&... args );		(since C++17)

Pushes a new element to the end of the queue. The element is constructed in-place, i.e. no copy or move operations are performed. The constructor of the element is called with exactly the same arguments as supplied to the function.

Effectively calls c.emplace_back(std::forward<Args>(args)...);

Parameters

args

-

arguments to forward to the constructor of the element

Return value

(none)	(until C++17)
The value or reference, if any, returned by the above call to Container::emplace_back.	(since C++17)

Complexity

Identical to the complexity of Container::emplace_back.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2783	C++17	emplace returned reference, breaking compatibility with pre-C++17 containers	returns decltype(auto)

See also

push	inserts element at the end (public member function)
pop	removes the first element (public member function)