/*
* Copyright (C) 2013 Apple Inc. 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 APPLE INC. ``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 APPLE INC. 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.
*/
#ifndef WTF_EnumClass_h
#define WTF_EnumClass_h
#include "wtf/Compiler.h"
namespace WTF {
// How to define a type safe enum list using the ENUM_CLASS macros?
// ===============================================================
// To get an enum list like this:
//
// enum class MyEnums {
// Value1,
// Value2,
// ...
// ValueN
// };
//
// ... write this:
//
// ENUM_CLASS(MyEnums) {
// Value1,
// Value2,
// ...
// ValueN
// } ENUM_CLASS_END(MyEnums);
//
// The ENUM_CLASS macros will use C++11's enum class if the compiler supports it.
// Otherwise, it will use the EnumClass template below.
#if COMPILER_SUPPORTS(CXX_STRONG_ENUMS)
#define ENUM_CLASS(__enumName) \
enum class __enumName
#define ENUM_CLASS_END(__enumName)
#else // !COMPILER_SUPPORTS(CXX_STRONG_ENUMS)
// How to define a type safe enum list using the EnumClass template?
// ================================================================
// Definition should be a struct that encapsulates an enum list.
// The enum list should be names Enums.
//
// Here's an example of how to define a type safe enum named MyEnum using
// the EnumClass template:
//
// struct MyEnumDefinition {
// enum Enums {
// ValueDefault,
// Value1,
// ...
// ValueN
// };
// };
// typedef EnumClass<MyEnumDefinition, MyEnumDefinition::ValueDefault> MyEnum;
//
// With that, you can now use MyEnum enum values as follow:
//
// MyEnum value1; // value1 is assigned MyEnum::ValueDefault by default.
// MyEnum value2 = MyEnum::Value1; // value2 is assigned MyEnum::Value1;
template <typename Definition>
class EnumClass : public Definition {
typedef enum Definition::Enums Value;
public:
ALWAYS_INLINE EnumClass() { }
ALWAYS_INLINE EnumClass(Value value) : m_value(value) { }
ALWAYS_INLINE Value value() const { return m_value; }
ALWAYS_INLINE bool operator==(const EnumClass other) { return m_value == other.m_value; }
ALWAYS_INLINE bool operator!=(const EnumClass other) { return m_value != other.m_value; }
ALWAYS_INLINE bool operator<(const EnumClass other) { return m_value < other.m_value; }
ALWAYS_INLINE bool operator<=(const EnumClass other) { return m_value <= other.m_value; }
ALWAYS_INLINE bool operator>(const EnumClass other) { return m_value > other.m_value; }
ALWAYS_INLINE bool operator>=(const EnumClass other) { return m_value >= other.m_value; }
ALWAYS_INLINE bool operator==(const Value value) { return m_value == value; }
ALWAYS_INLINE bool operator!=(const Value value) { return m_value != value; }
ALWAYS_INLINE bool operator<(const Value value) { return m_value < value; }
ALWAYS_INLINE bool operator<=(const Value value) { return m_value <= value; }
ALWAYS_INLINE bool operator>(const Value value) { return m_value > value; }
ALWAYS_INLINE bool operator>=(const Value value) { return m_value >= value; }
ALWAYS_INLINE operator Value() { return m_value; }
private:
Value m_value;
};
#define ENUM_CLASS(__enumName) \
struct __enumName ## Definition { \
enum Enums
#define ENUM_CLASS_END(__enumName) \
; \
}; \
typedef EnumClass< __enumName ## Definition > __enumName
#endif // !COMPILER_SUPPORTS(CXX_STRONG_ENUMS)
} // namespace WTF
#if !COMPILER_SUPPORTS(CXX_STRONG_ENUMS)
using WTF::EnumClass;
#endif
#endif // WTF_EnumClass_h