/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /*************************************************************************** * id.h * * Sun 16 Feb 2020 04:17:19 PM CET * Copyright 2020 André Nusser * andre.nusser@googlemail.com ****************************************************************************/ /* * This file is part of DrumGizmo. * * DrumGizmo is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * DrumGizmo is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with DrumGizmo; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #pragma once #include <cstdint> #include <functional> #include <limits> // Typesafe ID class such that there are compiler errors if different IDs are // mixed. The template parameter T is just there to assure this behavior. // Additionally, we have a member function which can check for validity. template <typename T> struct ID { public: using IDType = uint32_t; static constexpr IDType invalid_value = std::numeric_limits<IDType>::max(); ID(IDType id = invalid_value) : id(id) {} operator IDType() const { return id; } IDType operator+(ID<T> other) const { return id + other.id; } IDType operator+(int offset) const { return id + offset; } IDType operator+(size_t offset) const { return id + offset; } IDType operator-(ID<T> other) const { return id - other.id; } IDType operator-(int offset) const { return id - offset; } IDType operator/(int div) const { return id/div; } IDType operator+=(ID<T> other) { return id += other.id; } IDType operator-=(ID<T> other) { return id -= other.id; } IDType operator=(ID<T> other) { return id = other.id; } IDType operator++() { return ++id; } IDType operator--() { return --id; } bool operator!=(ID<T> other) const { return id != other.id; } bool valid() const { return id != invalid_value; } void invalidate() { id = invalid_value; } private: IDType id; }; // define custom hash function to be able to use IDs with maps/sets namespace std { template <typename T> struct hash<ID<T>> { using IDType = typename ID<T>::IDType; std::size_t operator()(ID<T> const& id) const noexcept { return std::hash<IDType>()(id); } }; } // std