std::priority_queue::priority_queue
From cppreference.com
< cpp | container | priority queue
(1) | ||
explicit priority_queue( const Compare& compare = Compare(),
const Container& cont = Container() ); |
(until C++11) | |
priority_queue( const Compare& compare, const Container& cont );
|
(since C++11) | |
explicit priority_queue( const Compare& compare = Compare(),
Container&& cont = Container() ); |
(2) | (since C++11) |
priority_queue( const priority_queue& other );
|
(3) | |
priority_queue( priority_queue&& other );
|
(4) | (since C++11) |
template< class Alloc >
explicit priority_queue( const Alloc& alloc ); |
(5) | (since C++11) |
template< class Alloc >
priority_queue( const Compare& compare, const Alloc& alloc ); |
(6) | (since C++11) |
template< class Alloc >
priority_queue( const Compare& compare, const Container& cont, |
(7) | (since C++11) |
template< class Alloc >
priority_queue( const Compare& compare, Container&& cont, |
(8) | (since C++11) |
template< class Alloc >
priority_queue( const priority_queue& other, const Alloc& alloc ); |
(9) | (since C++11) |
template< class Alloc >
priority_queue( priority_queue&& other, const Alloc& alloc ); |
(10) | (since C++11) |
template< class InputIt >
priority_queue( InputIt first, InputIt last, |
(11) | (since C++11) |
template< class InputIt >
priority_queue( InputIt first, InputIt last, |
(12) | (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
. Copy-constructs the comparison functor comp
with the contents of compare
. Calls std::make_heap(c.begin(), c.end(), comp). This is also the default constructor. (until C++11)
2) Move-constructs the underlying container
c
with std::move(cont). Move-constructs the comparison functor comp
with std::move(compare). Calls std::make_heap(c.begin(), c.end(), comp). This is also the default constructor. (since C++11)
3) Copy constructor. The adaptor is copy-constructed with the contents of other.c. The comparison functor is constructed with std::move(other.comp). (implicitly declared)
4) Move constructor. The adaptor is constructed with std::move(other.c).The comparison functor is constructed with std::move(other.comp). (implicitly declared)
5-10) 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. Effectively calls c(alloc). comp
is value-initialized.
6) Constructs the underlying container using
alloc
as allocator. Effectively calls c(alloc). Copy-constructs comp
from compare
.
7) Constructs the underlying container with the contents of
cont
and using alloc
as allocator. Effectively calls c(cont, alloc). Copy-constructs comp
from compare
.
8) Constructs the underlying container with the contents of
cont
using move semantics while utilising alloc
as allocator. Effectively calls c(std::move(cont), alloc). Copy-constructs comp
from compare
.
9) Constructs the adaptor with the contents of
other.c
and using alloc
as allocator. Effectively calls c(athor.c, alloc). Copy-constructs comp
from other.comp
.
10) Constructs the adaptor with the contents of
other
using move semantics while utilising alloc
as allocator. Effectively calls c(std::move(other.c), alloc). Move-constructs comp
from other.comp
.
11) Copy-constructs
c
from cont
and comp
from compare
. Then calls c.insert(c.end(), first, last);, and then calls std::make_heap(c.begin(), c.end(), comp);.
12) Move-constructs
c
from std::move(cont)
and comp
from std::move(compare)
. Then calls c.insert(c.end(), first, last);, and then calls std::make_heap(c.begin(), c.end(), comp);.
Contents |
[edit] 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 |
compare | - | the comparison function object to initialize the underlying comparison functor |
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 .
|
[edit] Complexity
1,3) O(N log(N)) comparisons, where N is cont.size().
Additionally, O(N) calls to the constructor of
value_type
, where N is cont.size().
2) O(N log(N)) comparisons, where N is cont.size().
4-6) Constant.
7) O(N log(N)) comparisons, where N is cont.size().
Additionally, O(N) calls to the constructor of
value_type
, where N is cont.size().
8) O(N log(N)) comparisons, where N is cont.size().
9) Linear in size of
other
.
10) Constant.
Additionally, O(N) calls to the constructor of
value_type
, where N is cont.size().[edit] Example
Run this code
#include <queue> #include <vector> #include <iostream> #include <functional> int main() { std::priority_queue<int> c1; c1.push(5); std::cout << c1.size() << '\n'; std::priority_queue<int> c2(c1); std::cout << c2.size() << '\n'; std::vector<int> vec={3, 1, 4, 1, 5}; std::priority_queue<int> c3(std::less<int>(), vec); std::cout << c3.size() << '\n'; }
Output:
1 1 5
[edit] See also
assigns values to the container adaptor (public member function) |