std::priority_queue emplace() method

since C++11

// Non const version only
template< class... Args >
void emplace( Args&&... args );

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.

note

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 emplace_back of the underlying container.

Example

Main.cpp

#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