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Diffstat (limited to 'src/id.h')
| -rw-r--r-- | src/id.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/id.h b/src/id.h new file mode 100644 index 0000000..384a3cc --- /dev/null +++ b/src/id.h @@ -0,0 +1,80 @@ +/* -*- 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 |