EnumRange.h File Reference

#include "CoreTypes.h"
#include <type_traits>

Go to the source code of this file.

Classes
struct	NEnumRangePrivate::TEnumRangeTraits< EnumType >
struct	NEnumRangePrivate::TEnumRange_Impl< EnumType, RangeType >
struct	NEnumRangePrivate::TEnumContiguousIterator< EnumType >
struct	NEnumRangePrivate::TEnumValueArrayIterator< EnumType >
struct	NEnumRangePrivate::TEnumRange_Impl< EnumType, 0 >
struct	NEnumRangePrivate::TEnumRange_Impl< EnumType, 1 >
struct	UE::EnumFlags::Private::TIterator< EnumType >
struct	UE::EnumFlags::Private::TRange< EnumType >
struct	TEnumRange< EnumType >

Namespaces
namespace	NEnumRangePrivate
namespace	UE
namespace	UE::EnumFlags
namespace	UE::EnumFlags::Private

Macros
#define	ENUM_RANGE_BY_COUNT(EnumType, Count)   ENUM_RANGE_BY_FIRST_AND_LAST(EnumType, 0, (std::underlying_type_t<EnumType>)(Count) - 1)
#define	ENUM_RANGE_BY_FIRST_AND_LAST(EnumType, First, Last)
#define	ENUM_RANGE_BY_VALUES(EnumType, ...)

Functions
template<typename EnumType >
UE::EnumFlags::Private::TRange< EnumType >	MakeFlagsRange (EnumType Flags)

Macro Definition Documentation

ENUM_RANGE_BY_COUNT

#define ENUM_RANGE_BY_COUNT	(		EnumType,
			Count
	)		ENUM_RANGE_BY_FIRST_AND_LAST(EnumType, 0, (std::underlying_type_t<EnumType>)(Count) - 1)

Defines a contiguous enum range containing Count values, starting from zero:

Example:

enum class ECountedThing { First, Second, Third,

Count };

// Defines iteration over ECountedThing to be: First, Second, Third ENUM_RANGE_BY_COUNT(ECountedThing, ECountedThing::Count)

ENUM_RANGE_BY_FIRST_AND_LAST

#define ENUM_RANGE_BY_FIRST_AND_LAST	(		EnumType,
			First,
			Last
	)

Value:

    template <> \
    struct NEnumRangePrivate::TEnumRangeTraits<EnumType> \
    { \
        enum { RangeType = 0 }; \
        static constexpr std::underlying_type_t<EnumType> Begin = (std::underlying_type_t<EnumType>)(First); \
        static constexpr std::underlying_type_t<EnumType> End   = (std::underlying_type_t<EnumType>)(Last) + 1; \
    };

Defines a contiguous enum range with specific start and end values:

Example:

enum class EDoubleEndedThing { Invalid,

First, Second, Third,

Count };

// Defines iteration over EDoubleEndedThing to be: First, Second, Third ENUM_RANGE_BY_FIRST_AND_LAST(EDoubleEndedThing, EDoubleEndedThing::First, EDoubleEndedThing::Third)

ENUM_RANGE_BY_VALUES

#define ENUM_RANGE_BY_VALUES	(		EnumType,
			...
	)

Value:

    template <> \
    struct NEnumRangePrivate::TEnumRangeTraits<EnumType> \
    { \
        enum { RangeType = 1 }; \
        template <typename Dummy> \
        static const EnumType* GetPointer(bool bLast) \
        { \
            static constexpr EnumType Values[] = { __VA_ARGS__ }; \
            return bLast ? Values + sizeof(Values) / sizeof(EnumType) : Values; \
        } \
    };

Defines a non-contiguous enum range with specific individual values:

Example:

enum class ERandomValuesThing { First = 2, Second = 3, Third = 5, Fourth = 7, Fifth = 11 };

// Defines iteration over ERandomValuesThing to be: First, Second, Third, Fourth, Fifth ENUM_RANGE_BY_VALUES(ERandomValuesThing, ERandomValuesThing::First, ERandomValuesThing::Second, ERandomValuesThing::Third, ERandomValuesThing::Fourth, ERandomValuesThing::Fifth)

Function Documentation

MakeFlagsRange()

template<typename EnumType >

UE::EnumFlags::Private::TRange< EnumType > MakeFlagsRange

(

EnumType

Flags

)

Make a range for iterating over set flags in a flags enum.

Example:

EFlagThing Flags = EFlagThing::A | EFlagThing::B; for (EFlagThing Flag : MakeFlagsRange(Flags)) { // Loop is run twice, once with Flag = EFlagThing::A, once with Flag = EFlagThing::B ... }