The standard priority_queue<T>
can be customized through inheritance. It has protected members c
and comp
that can be referenced in a descendant class.
template<typename T>
class custom_priority_queue : public std::priority_queue<T, std::vector<T>>
{
public:
bool remove(const T& value) {
auto it = std::find(this->c.begin(), this->c.end(), value);
if (it == this->c.end()) {
return false;
}
if (it == this->c.begin()) {
// deque the top element
this->pop();
}
else {
// remove element and re-heap
this->c.erase(it);
std::make_heap(this->c.begin(), this->c.end(), this->comp);
}
return true;
}
};
void main()
{
custom_priority_queue<int> queue;
queue.push(10);
queue.push(2);
queue.push(4);
queue.push(6);
queue.push(3);
queue.remove(6);
while (!queue.empty())
{
std::cout << queue.top();
queue.pop();
if (!queue.empty())
{
std::cout << ", ";
}
}
}
Output:
10, 4, 3, 2