std::priority_queue<T,Container,Compare>::emplace

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Iterator invalidation

Member function table

Non-member function table

 

std::priority_queue

Member functions

priority_queue::priority_queue

priority_queue::~priority_queue

priority_queue::operator=

Element access

priority_queue::top

Capacity

priority_queue::empty

priority_queue::size

Modifiers

priority_queue::push

priority_queue::push_range (C++23)

priority_queue::emplace (C++11)

priority_queue::pop

priority_queue::swap (C++11)

Non-member functions

std::swap (C++11)

Deduction guides(C++17)

Helper classes

std::uses_allocator (C++11)

 

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

Pushes a new element to the priority 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)...); std::push_heap(c.begin(), c.end(), comp);

Parameters

args

-

arguments to forward to the constructor of the element

Return value

(none)

Complexity

Logarithmic number of comparisons plus the complexity of Container::emplace_back.

Example

Run this code

#include <iostream>
#include <queue>
 
struct S
{
    int id;
 
    S(int i, double d, std::string s) : id{i}
    {
        std::cout << "S::S(" << i << ", " << d << ", \"" << s << "\");\n";
    }
 
    friend bool operator< (S const& x, S const& y) { return x.id < y.id; }
};
 
int main()
{
    std::priority_queue<S> adaptor;
 
    adaptor.emplace(42, 3.14, "C++");
 
    std::cout << "id: " << adaptor.top().id << '\n';
}

Output:

S::S(42, 3.14, "C++")
id = 42

See also

push	inserts element and sorts the underlying container (public member function)
pop	removes the top element (public member function)