ericw-tools/include/common/bitflags.hh

87 lines
2.8 KiB
C++

/* Copyright (C) 1996-1997 Id Software, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
See file, 'COPYING', for details.
*/
#pragma once
#include <bitset>
#include <type_traits>
template<typename Enum>
struct bitflags
{
static_assert(std::is_enum_v<Enum>, "Must be enum");
private:
using type = typename std::underlying_type_t<Enum>;
std::bitset<sizeof(type) * 8> _bits{};
constexpr bitflags(const std::bitset<sizeof(type) * 8> &bits) : _bits(bits) { }
public:
constexpr bitflags() { }
constexpr bitflags(const Enum &enumValue) : _bits(static_cast<type>(enumValue)) { }
constexpr bitflags(const bitflags &copy) = default;
constexpr bitflags(bitflags &&move) noexcept = default;
constexpr bitflags &operator=(const bitflags &copy) = default;
constexpr bitflags &operator=(bitflags &&move) noexcept = default;
inline explicit operator bool() const { return _bits.any(); }
inline bool operator!() const { return !_bits.any(); }
inline operator Enum() const { return static_cast<Enum>(_bits.to_ulong()); }
inline bitflags &operator|=(const bitflags &r)
{
_bits |= r._bits;
return *this;
}
inline bitflags &operator&=(const bitflags &r)
{
_bits &= r._bits;
return *this;
}
inline bitflags &operator^=(const bitflags &r)
{
_bits ^= r._bits;
return *this;
}
inline bitflags operator|(const bitflags &r) { return bitflags(*this) |= r; }
inline bitflags operator&(const bitflags &r) { return bitflags(*this) &= r; }
inline bitflags operator^(const bitflags &r) { return bitflags(*this) ^= r; }
inline bitflags operator~() const { return ~_bits; }
inline bool operator==(const bitflags &r) const { return _bits == r._bits; }
inline bool operator!=(const bitflags &r) const { return _bits != r._bits; }
inline bool operator==(const Enum &r) const { return _bits == bitflags(r)._bits; }
inline bool operator!=(const Enum &r) const { return _bits != bitflags(r)._bits; }
};
// fetch integral representation of the value at bit N
template<typename T>
constexpr auto nth_bit(T l)
{
return static_cast<T>(1) << l;
}