std::priority_queue<T,Container,Compare>::priority_queue
priority_queue() : priority_queue(Compare(), Container()) {} |
(1) | (since C++11) |
explicit priority_queue( const Compare& compare ) : priority_queue(compare, Container()) {} |
(2) | (since C++11) |
(3) | ||
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) | |
priority_queue( const Compare& compare, Container&& cont ); |
(4) | (since C++11) |
priority_queue( const priority_queue& other ); |
(5) | |
priority_queue( priority_queue&& other ); |
(6) | (since C++11) |
template< class InputIt > priority_queue( InputIt first, InputIt last, |
(7) | (since C++11) |
(8) | ||
template< class InputIt > priority_queue( InputIt first, InputIt last, |
(until C++11) | |
template< class InputIt > priority_queue( InputIt first, InputIt last, |
(since C++11) | |
template< class InputIt > priority_queue( InputIt first, InputIt last, |
(9) | (since C++11) |
template< class Alloc > explicit priority_queue( const Alloc& alloc ); |
(10) | (since C++11) |
template< class Alloc > priority_queue( const Compare& compare, const Alloc& alloc ); |
(11) | (since C++11) |
template< class Alloc > priority_queue( const Compare& compare, const Container& cont, |
(12) | (since C++11) |
template< class Alloc > priority_queue( const Compare& compare, Container&& cont, |
(13) | (since C++11) |
template< class Alloc > priority_queue( const priority_queue& other, const Alloc& alloc ); |
(14) | (since C++11) |
template< class Alloc > priority_queue( priority_queue&& other, const Alloc& alloc ); |
(15) | (since C++11) |
template< class InputIt, class Alloc > priority_queue( InputIt first, InputIt last, const Alloc& alloc ); |
(16) | (since C++11) |
template< class InputIt, class Alloc > priority_queue( InputIt first, InputIt last, const Compare& compare, |
(17) | (since C++11) |
template< class InputIt, class Alloc > priority_queue( InputIt first, InputIt last, const Compare& compare, |
(18) | (since C++11) |
template< class InputIt, class Alloc > priority_queue( InputIt first, InputIt last, const Compare& compare, |
(19) | (since C++11) |
template< container-compatible-range<T> R > priority_queue( std::from_range_t, R&& rg, |
(20) | (since C++23) |
template< container-compatible-range<T> R, class Alloc > priority_queue( std::from_range_t, R&& rg, |
(21) | (since C++23) |
template< container-compatible-range<T> R, class Alloc > priority_queue( std::from_range_t, R&& rg, const Alloc& alloc ); |
(22) | (since C++23) |
Constructs new underlying container of the container adaptor from a variety of data sources.
InputIt
satisfies LegacyInputIterator.Note that how an implementation checks whether a type satisfies LegacyInputIterator is unspecified, except that integral types are required to be rejected.
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 | - | a range [ first, last) of elements to initialize with
|
rg | - | a container compatible range, that is, an input_range whose elements are convertible to T
|
Type requirements | ||
-Alloc must meet the requirements of Allocator.
| ||
-Compare must meet the requirements of Compare.
| ||
-Container must meet the requirements of Container. The allocator-extended constructors are only defined if Container meets the requirements of AllocatorAwareContainer.
| ||
-InputIt must meet the requirements of LegacyInputIterator.
|
[edit] Complexity
value_type
, where N is cont.size().value_type
, where N is cont.size() and M is std::distance(first, last).Alloc
compares equal to the allocator of other. Linear in size of other otherwise.value_type
(present if Alloc
does not compare equal to the allocator of other), where N is cont.size() and M is std::distance(first, last).value_type
, where N is ranges::distance(rg).This section is incomplete |
[edit] Notes
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_containers_ranges |
202202L | (C++23) | Ranges-aware construction and insertion; overloads (20-22) |
[edit] Example
#include <complex> #include <functional> #include <iostream> #include <queue> #include <vector> int main() { std::priority_queue<int> pq1; pq1.push(5); std::cout << "pq1.size() = " << pq1.size() << '\n'; std::priority_queue<int> pq2 {pq1}; std::cout << "pq2.size() = " << pq2.size() << '\n'; std::vector<int> vec {3, 1, 4, 1, 5}; std::priority_queue<int> pq3 {std::less<int>(), vec}; std::cout << "pq3.size() = " << pq3.size() << '\n'; for (std::cout << "pq3 : "; !pq3.empty(); pq3.pop()) std::cout << pq3.top() << ' '; std::cout << '\n'; // Demo With Custom Comparator: using my_value_t = std::complex<double>; using my_container_t = std::vector<my_value_t>; auto my_comp = [](const my_value_t& z1, const my_value_t& z2) { return z2.real() < z1.real(); }; std::priority_queue<my_value_t, my_container_t, decltype(my_comp)> pq4{my_comp}; using namespace std::complex_literals; pq4.push(5.0 + 1i); pq4.push(3.0 + 2i); pq4.push(7.0 + 3i); for (; !pq4.empty(); pq4.pop()) { const auto& z = pq4.top(); std::cout << "pq4.top() = " << z << '\n'; } // TODO: C++23 range-aware ctors }
Output:
pq1.size() = 1 pq2.size() = 1 pq3.size() = 5 pq3 : 5 4 3 1 1 pq4.top() = (3,2) pq4.top() = (5,1) pq4.top() = (7,3)
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
P0935R0 | C++11 | default constructor and constructor (4) were explicit | made implicit |
LWG 3506 | C++11 | allocator-extended iterator-pair constructors were missing | added |
LWG 3522 | C++11 | constraints on iterator-pair constructors were missing | added |
LWG 3529 | C++11 | construction from a pair of iterators called insert
|
constructs the container from them |
[edit] See also
assigns values to the container adaptor (public member function) |