serenity/AK/EnumBits.h
Brian Gianforcaro c825159f01 AK: Add AK_ENUM_BITWISE_OPERATORS(..) to enable type-safe enum bitwise operations
This change introduces `AK_ENUM_BITWISE_OPERATORS(..)` which when
enabled for an enum, will automatically declare all the necessary
bitwise operators for that enum.

This allows bit masks enums to be used as first class, type safe, citizens.
2021-03-08 18:47:40 +01:00

102 lines
6.3 KiB
C

/*
* Copyright (c) 2021, Brian Gianforcaro <b.gianfo@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "AK/StdLibExtras.h"
// Enables bitwise operators for the specified Enum type.
//
#define AK_ENUM_BITWISE_OPERATORS(Enum) \
_AK_ENUM_BITWISE_OPERATORS_INTERNAL(Enum, )
// Enables bitwise operators for the specified Enum type, this
// version is meant for use on enums which are private to the
// containing type.
//
#define AK_ENUM_BITWISE_FRIEND_OPERATORS(Enum) \
_AK_ENUM_BITWISE_OPERATORS_INTERNAL(Enum, friend)
#define _AK_ENUM_BITWISE_OPERATORS_INTERNAL(Enum, Prefix) \
\
[[nodiscard]] Prefix constexpr inline Enum operator|(Enum lhs, Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
return static_cast<Enum>( \
static_cast<Type>(lhs) | static_cast<Type>(rhs)); \
} \
\
[[nodiscard]] Prefix constexpr inline Enum operator&(Enum lhs, Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
return static_cast<Enum>( \
static_cast<Type>(lhs) & static_cast<Type>(rhs)); \
} \
\
[[nodiscard]] Prefix constexpr inline Enum operator^(Enum lhs, Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
return static_cast<Enum>( \
static_cast<Type>(lhs) ^ static_cast<Type>(rhs)); \
} \
\
[[nodiscard]] Prefix constexpr inline Enum operator~(Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
return static_cast<Enum>( \
~static_cast<Type>(rhs)); \
} \
\
Prefix constexpr inline Enum& operator|=(Enum& lhs, Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
lhs = static_cast<Enum>( \
static_cast<Type>(lhs) | static_cast<Type>(rhs)); \
return lhs; \
} \
\
Prefix constexpr inline Enum& operator&=(Enum& lhs, Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
lhs = static_cast<Enum>( \
static_cast<Type>(lhs) & static_cast<Type>(rhs)); \
return lhs; \
} \
\
Prefix constexpr inline Enum& operator^=(Enum& lhs, Enum rhs) \
{ \
using Type = UnderlyingType<Enum>::Type; \
lhs = static_cast<Enum>( \
static_cast<Type>(lhs) ^ static_cast<Type>(rhs)); \
return lhs; \
} \
\
Prefix constexpr inline bool has_flag(Enum value, Enum mask) \
{ \
using Type = UnderlyingType<Enum>::Type; \
return static_cast<Type>(value & mask) != 0; \
}