Files
deskflow/src/lib/base/PriorityQueue.h

131 lines
2.4 KiB
C++

/*
* Deskflow -- mouse and keyboard sharing utility
* SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
* SPDX-FileCopyrightText: (C) 2003 Chris Schoeneman
* SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
*/
#pragma once
#include <algorithm>
#include <vector>
//! A priority queue with an iterator
/*!
This priority queue is the same as a standard priority queue except:
it sorts by std::greater, it has a forward iterator through the elements
(which can appear in any order), and its contents can be swapped.
*/
template <
class T, class Container = std::vector<T>,
#if defined(_MSC_VER)
class Compare = std::greater<Container::value_type>>
#else
class Compare = std::greater<typename Container::value_type>>
#endif
class PriorityQueue
{
public:
using value_type = Container::value_type;
using size_type = Container::size_type;
using iterator = Container::iterator;
using const_iterator = Container::const_iterator;
using container_type = Container;
PriorityQueue() = default;
explicit PriorityQueue(Container &swappedIn)
{
swap(swappedIn);
}
~PriorityQueue() = default;
//! @name manipulators
//@{
//! Add element
void push(const value_type &v)
{
c.push_back(v);
std::ranges::push_heap(c, comp);
}
//! Remove head element
void pop()
{
std::ranges::pop_heap(c, comp);
c.pop_back();
}
//! Erase element
void erase(iterator i)
{
c.erase(i);
std::ranges::make_heap(c, comp);
}
//! Get start iterator
iterator begin()
{
return c.begin();
}
//! Get end iterator
iterator end()
{
return c.end();
}
//! Swap contents with another priority queue
void swap(PriorityQueue<T, Container, Compare> &q) noexcept
{
c.swap(q.c);
}
//! Swap contents with another container
void swap(Container &c2) noexcept
{
c.swap(c2);
std::ranges::make_heap(c, comp);
}
//@}
//! @name accessors
//@{
//! Returns true if there are no elements
bool empty() const
{
return c.empty();
}
//! Returns the number of elements
size_type size() const
{
return c.size();
}
//! Returns the head element
const value_type &top() const
{
return c.front();
}
//! Get start iterator
const_iterator begin() const
{
return c.begin();
}
//! Get end iterator
const_iterator end() const
{
return c.end();
}
//@}
private:
Container c;
[[no_unique_address]] Compare comp;
};