Namespaces
Variants
Views
Actions

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

From cppreference.com
 
 
 
 
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);

Contents

[edit] Parameters

args - arguments to forward to the constructor of the element

[edit] Return value

(none)

[edit] Complexity

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

[edit] Example

#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> queue;
    queue.emplace(42, 3.14, "C++");
    std::cout << "id: " << queue.top().id << '\n';
}

Output:

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

[edit] See also

inserts element and sorts the underlying container
(public member function) [edit]
removes the top element
(public member function) [edit]