bitmask_operators.h

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/* Copyright (C) 2017-2021 GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
   SPDX-License-Identifier: GPL-3.0-only
   Authors: Pierre-Alain Loizeau [committer] */
 
#ifndef JSS_BITMASK_HPP
#define JSS_BITMASK_HPP
 
// (C) Copyright 2015 Just Software Solutions Ltd
//
// Distributed under the Boost Software License, Version 1.0.
//
// Boost Software License - Version 1.0 - August 17th, 2003
//
// Permission is hereby granted, free of charge, to any person or
// organization obtaining a copy of the software and accompanying
// documentation covered by this license (the "Software") to use,
// reproduce, display, distribute, execute, and transmit the
// Software, and to prepare derivative works of the Software, and
// to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire
// statement, including the above license grant, this restriction
// and the following disclaimer, must be included in all copies
// of the Software, in whole or in part, and all derivative works
// of the Software, unless such copies or derivative works are
// solely in the form of machine-executable object code generated
// by a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
// KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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#include <type_traits>
 
template<typename E>
struct enable_bitmask_operators
{
    static const bool enable = false;
};
 
/*********** Preproc macro for simpler use ****************************/
/* copied 17/07/2017 from
 * http://blog.bitwigglers.org/using-enum-classes-as-type-safe-bitmasks/
 */
#define ENABLE_BITMASK_OPERATORS(x)      \
    template<>                           \
    struct enable_bitmask_operators<x>   \
    {                                    \
        static const bool enable = true; \
    };
/**********************************************************************/
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E>::type operator|(E lhs, E rhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    return static_cast<E>(static_cast<underlying>(lhs) | static_cast<underlying>(rhs));
}
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E>::type operator&(E lhs, E rhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    return static_cast<E>(static_cast<underlying>(lhs) & static_cast<underlying>(rhs));
}
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E>::type operator^(E lhs, E rhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    return static_cast<E>(static_cast<underlying>(lhs) ^ static_cast<underlying>(rhs));
}
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E>::type operator~(E lhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    return static_cast<E>(~static_cast<underlying>(lhs));
}
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E&>::type operator|=(E& lhs, E rhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    lhs = static_cast<E>(static_cast<underlying>(lhs) | static_cast<underlying>(rhs));
    return lhs;
}
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E&>::type operator&=(E& lhs, E rhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    lhs = static_cast<E>(static_cast<underlying>(lhs) & static_cast<underlying>(rhs));
    return lhs;
}
 
template<typename E>
typename std::enable_if<enable_bitmask_operators<E>::enable, E&>::type operator^=(E& lhs, E rhs)
{
    typedef typename std::underlying_type<E>::type underlying;
    lhs = static_cast<E>(static_cast<underlying>(lhs) ^ static_cast<underlying>(rhs));
    return lhs;
}
 
#endif