std::priority_queue::emplace - std::priority_queue::emplace
template< class... Args > (since C++11)
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.
Effectively calls c.emplace_back(std::forward<Args>(args)...);
std::push_heap(c.begin(), c.end(), comp);
args - arguments to forward to the constructor of the element
Logarithmic number of comparisons plus the complexity of
Container::emplace_back.
// 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';
}
S::S(42, 3.14, "C++")
id = 42
push inserts element and sorts the underlying container
(public member function)
pop removes the top element
(public member function)