std::queue::queue
From cppreference.com
(1) | ||
explicit queue( const Container& cont = Container() ); |
(until C++11) | |
explicit queue( const Container& cont ); |
(since C++11) | |
explicit queue( Container&& cont = Container() ); |
(2) | (since C++11) |
queue( const queue& other ); |
(3) | |
queue( queue&& other ); |
(4) | (since C++11) |
template< class Alloc > explicit queue( const Alloc& alloc ); |
(5) | (since C++11) |
template< class Alloc > queue( const Container& cont, const Alloc& alloc ); |
(6) | (since C++11) |
template< class Alloc > queue( Container&& cont, const Alloc& alloc ); |
(7) | (since C++11) |
template< class Alloc > queue( const queue& other, const Alloc& alloc ); |
(8) | (since C++11) |
template< class Alloc > queue( queue&& other, const Alloc& alloc ); |
(9) | (since C++11) |
Constructs new underlying container of the container adaptor from a variety of data sources.
1) Copy-constructs the underlying container
c
with the contents of cont
. This is also the default constructor (until C++11)2) Move-constructs the underlying container
c
with std::move(cont). This is also the default constructor (since C++11)3) Copy constructor. The adaptor is copy-constructed with the contents of other.c. (implicitly declared)
4) Move constructor. The adaptor is constructed with std::move(other.c). (implicitly declared)
5-9) The following constructors are only defined if std::uses_allocator<container_type, Alloc>::value == true, that is, if the underlying container is an allocator-aware container (true for all standard library containers).
5) Constructs the underlying container using
alloc
as allocator, as if by c(alloc).6) Constructs the underlying container with the contents of
cont
and using alloc
as allocator, as if by c(cont, alloc).7) Constructs the underlying container with the contents of
cont
using move semantics while utilising alloc
as allocator, as if by c(std::move(cont), alloc).8) Constructs the adaptor with the contents of
other.c
and using alloc
as allocator, as if by c(other.c, alloc).9) Constructs the adaptor with the contents of
other
using move semantics while utilising alloc
as allocator, as if by c(std::move(other.c), alloc).Parameters
alloc | - | allocator to use for all memory allocations of the underlying container |
other | - | another container adaptor to be used as source to initialize the underlying container |
cont | - | container to be used as source to initialize the underlying container |
first, last | - | range of elements to initialize with |
Type requirements | ||
-Alloc must meet the requirements of Allocator .
| ||
-Container must meet the requirements of Container . The constructors (5-10) are only defined if Container meets the requirements of AllocatorAwareContainer
| ||
-InputIt must meet the requirements of InputIterator .
|
Complexity
1, 3, 5, 6, 8: linear in cont
or other
2, 4, 7, 9: constant
This section is incomplete |
Example
Run this code
#include <queue> #include <deque> #include <iostream> int main() { std::queue<int> c1; c1.push(5); std::cout << c1.size() << '\n'; std::queue<int> c2(c1); std::cout << c2.size() << '\n'; std::deque<int> deq {3, 1, 4, 1, 5}; std::queue<int> c3(deq); std::cout << c3.size() << '\n'; }
Output:
1 1 5
See also
assigns values to the container adaptor (public member function) |