550 lines
24 KiB
C++
550 lines
24 KiB
C++
#pragma once
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#include "CoreTypes.h"
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#include "Templates/Invoke.h"
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#include "Templates/TypeHash.h"
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#include "Templates/Utility.h"
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#include "TypeTraits/TypeTraits.h"
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#include "Miscellaneous/AssertionMacros.h"
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NAMESPACE_REDCRAFT_BEGIN
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NAMESPACE_MODULE_BEGIN(Redcraft)
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NAMESPACE_MODULE_BEGIN(Utility)
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NAMESPACE_PRIVATE_BEGIN
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template <typename T, typename... Types>
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struct TVariantAlternativeIndex;
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template <typename T, typename U, typename... Types>
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struct TVariantAlternativeIndex<T, U, Types...>
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: TConstant<size_t, TIsSame<T, U>::Value ? 0 : (TVariantAlternativeIndex<T, Types...>::Value == INDEX_NONE
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? INDEX_NONE : TVariantAlternativeIndex<T, Types...>::Value + 1)>
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{ };
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template <typename T>
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struct TVariantAlternativeIndex<T> : TConstant<size_t, INDEX_NONE> { };
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template <size_t I, typename... Types>
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struct TVariantAlternativeType;
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template <size_t I, typename T, typename... Types>
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struct TVariantAlternativeType<I, T, Types...>
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{
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static_assert(I < sizeof...(Types) + 1, "Variant type index is invalid");
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using Type = TVariantAlternativeType<I - 1, Types...>::Type;
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};
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template <typename T, typename... Types>
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struct TVariantAlternativeType<0, T, Types...> { using Type = T; };
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template <>
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struct TVariantAlternativeType<0> { };
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template <typename T, typename... Types>
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struct TVariantSelectedType;
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template <typename T, typename U, typename... Types>
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struct TVariantSelectedType<T, U, Types...>
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{
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using TypeAlternativeA = typename TConditional<TIsConstructible<U, T&&>::Value, U, void>::Type;
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using TypeAlternativeB = typename TVariantSelectedType<T, Types...>::Type;
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using Type = typename TConditional<TIsSame<typename TRemoveCVRef<TypeAlternativeA>::Type, void>::Value, TypeAlternativeB,
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typename TConditional<TIsSame<typename TRemoveCVRef<TypeAlternativeB>::Type, void>::Value, TypeAlternativeA,
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typename TConditional<TIsSame<typename TRemoveCVRef<TypeAlternativeB>::Type, typename TRemoveCVRef<T>::Type>::Value, TypeAlternativeB, TypeAlternativeA>::Type>::Type>::Type;
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// 0 - Type not found
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// 1 - Same type found
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// 2 - Multiple types found
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// 3 - The type found
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static constexpr uint8 Flag = TIsSame<typename TRemoveCVRef<Type>::Type, void>::Value ? 0 :
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TIsSame<typename TRemoveCVRef<TypeAlternativeA>::Type, typename TRemoveCVRef<TypeAlternativeB>::Type>::Value ? 2 :
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TIsSame<typename TRemoveCVRef< Type>::Type, typename TRemoveCVRef< T>::Type>::Value ? 1 :
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!TIsSame<typename TRemoveCVRef<TypeAlternativeA>::Type, void>::Value && !TIsSame<TypeAlternativeB, void>::Value ? 2 : 3;
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static constexpr bool Value = Flag & 1;
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};
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template <typename T>
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struct TVariantSelectedType<T>
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{
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static constexpr uint8 Flag = 0;
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using Type = void;
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};
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template <typename T>
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constexpr void VariantDestroy(void* InValue)
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{
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if constexpr (!TIsTriviallyDestructible<T>::Value)
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{
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typedef T DestructOptionalType;
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reinterpret_cast<T*>(InValue)->DestructOptionalType::~DestructOptionalType();
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}
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}
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using FVariantDestroyFunc = void(*)(void*);
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template <typename T>
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constexpr void VariantCopyConstruct(void* Target, const void* Source)
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{
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if constexpr (!TIsCopyConstructible<T>::Value || TIsConst<T>::Value) check_no_entry();
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else new(reinterpret_cast<T*>(Target)) T(*reinterpret_cast<const T*>(Source));
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}
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using FVariantCopyConstructFunc = void(*)(void*, const void*);
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template <typename T>
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constexpr void VariantMoveConstruct(void* Target, void* Source)
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{
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if constexpr (!TIsMoveConstructible<T>::Value || TIsConst<T>::Value) check_no_entry();
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else new(reinterpret_cast<T*>(Target)) T(MoveTemp(*reinterpret_cast<T*>(Source)));
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}
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using FVariantMoveConstructFunc = void(*)(void*, void*);
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template <typename T>
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constexpr void VariantCopyAssign(void* Target, const void* Source)
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{
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if constexpr (!TIsCopyAssignable<T>::Value || TIsConst<T>::Value) check_no_entry();
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else *reinterpret_cast<T*>(Target) = *reinterpret_cast<const T*>(Source);
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}
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using FVariantCopyAssignFunc = void(*)(void*, const void*);
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template <typename T>
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constexpr void VariantMoveAssign(void* Target, void* Source)
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{
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if constexpr (!TIsMoveAssignable<T>::Value || TIsConst<T>::Value) check_no_entry();
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else *reinterpret_cast<T*>(Target) = MoveTemp(*reinterpret_cast<T*>(Source));
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}
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using FVariantMoveAssignFunc = void(*)(void*, void*);
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template <typename T>
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constexpr bool VariantEqualityOperator(const void* LHS, const void* RHS)
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{
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if constexpr (!CEqualityComparable<T>) check_no_entry();
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else return *reinterpret_cast<const T*>(LHS) == *reinterpret_cast<const T*>(RHS);
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return false;
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}
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using FVariantEqualityOperatorFunc = bool(*)(const void*, const void*);
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template <typename T>
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constexpr bool VariantInequalityOperator(const void* LHS, const void* RHS)
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{
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if constexpr (!CEqualityComparable<T>) check_no_entry();
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else return *reinterpret_cast<const T*>(LHS) != *reinterpret_cast<const T*>(RHS);
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return false;
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}
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using FVariantInequalityOperatorFunc = bool(*)(const void*, const void*);
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template <typename... Types>
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struct TVariantHelper
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{
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static constexpr FVariantDestroyFunc DestroyFuncs[] = { VariantDestroy<Types>... };
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static constexpr FVariantCopyConstructFunc CopyConstructFuncs[] = { VariantCopyConstruct<Types>... };
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static constexpr FVariantMoveConstructFunc MoveConstructFuncs[] = { VariantMoveConstruct<Types>... };
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static constexpr FVariantCopyAssignFunc CopyAssignFuncs[] = { VariantCopyAssign<Types>... };
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static constexpr FVariantMoveAssignFunc MoveAssignFuncs[] = { VariantMoveAssign<Types>... };
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static constexpr FVariantEqualityOperatorFunc EqualityOperatorFuncs[] = { VariantEqualityOperator<Types>... };
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static constexpr FVariantInequalityOperatorFunc InequalityOperatorFuncs[] = { VariantInequalityOperator<Types>... };
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};
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template <typename R, typename F, typename T>
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constexpr R VariantVisitLValue(F&& Func, void* Arg)
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{
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if constexpr(TIsVoid<R>::Value) Invoke(Forward<F>(Func), *reinterpret_cast<T*>(Arg));
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else return InvokeResult<R>(Forward<F>(Func), *reinterpret_cast<T*>(Arg));
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}
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template <typename R, typename F>
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using FVariantVisitLValueFunc = R(*)(F&&, void*);
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template <typename R, typename F, typename T>
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constexpr R VariantVisitRValue(F&& Func, void* Arg)
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{
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if constexpr (TIsVoid<R>::Value) Invoke(Forward<F>(Func), MoveTemp(*reinterpret_cast<T*>(Arg)));
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else return InvokeResult<R>(Forward<F>(Func), MoveTemp(*reinterpret_cast<T*>(Arg)));
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}
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template <typename R, typename F>
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using FVariantVisitRValueFunc = R(*)(F&&, void*);
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template <typename R, typename F, typename T>
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constexpr R VariantVisitConstLValue(F&& Func, const void* Arg)
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{
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if constexpr (TIsVoid<R>::Value) Invoke(Forward<F>(Func), *reinterpret_cast<const T*>(Arg));
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else return InvokeResult<R>(Forward<F>(Func), *reinterpret_cast<const T*>(Arg));
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}
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template <typename R, typename F>
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using FVariantVisitConstLValueFunc = R(*)(F&&, const void*);
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template <typename R, typename F, typename T>
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constexpr R VariantVisitConstRValue(F&& Func, const void* Arg)
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{
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if constexpr (TIsVoid<R>::Value) Invoke(Forward<F>(Func), MoveTemp(*reinterpret_cast<const T*>(Arg)));
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else return InvokeResult<R>(Forward<F>(Func), MoveTemp(*reinterpret_cast<const T*>(Arg)));
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}
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template <typename R, typename F>
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using FVariantVisitConstRValueFunc = R(*)(F&&, const void*);
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template <typename R, typename F, typename... Types>
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struct TVariantVisitHelper
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{
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static constexpr FVariantVisitLValueFunc<R, F> VisitLValueFuncs[] = { VariantVisitLValue<R, F, Types>... };
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static constexpr FVariantVisitRValueFunc<R, F> VisitRValueFuncs[] = { VariantVisitRValue<R, F, Types>... };
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static constexpr FVariantVisitConstLValueFunc<R, F> VisitConstLValueFuncs[] = { VariantVisitConstLValue<R, F, Types>... };
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static constexpr FVariantVisitConstRValueFunc<R, F> VisitConstRValueFuncs[] = { VariantVisitConstRValue<R, F, Types>... };
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};
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NAMESPACE_PRIVATE_END
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template <typename... Types> requires (true && ... && (TIsObject<Types>::Value && !TIsArray<Types>::Value && TIsDestructible<Types>::Value))
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struct TVariant
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{
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static constexpr size_t AlternativeSize = sizeof...(Types);
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template <size_t I> struct TAlternativeType : NAMESPACE_PRIVATE::TVariantAlternativeType<I, Types...> { };
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template <typename T> struct TAlternativeIndex : NAMESPACE_PRIVATE::TVariantAlternativeIndex<T, Types...> { };
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constexpr TVariant() : TypeIndex(INDEX_NONE) { };
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constexpr TVariant(FInvalid) : TVariant() { };
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constexpr TVariant(const TVariant& InValue) requires (true && ... && TIsCopyConstructible<Types>::Value)
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: TypeIndex(InValue.GetIndex())
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{
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if (GetIndex() != INDEX_NONE) FHelper::CopyConstructFuncs[InValue.GetIndex()](&Value, &InValue.Value);
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}
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constexpr TVariant(TVariant&& InValue) requires (true && ... && TIsMoveConstructible<Types>::Value)
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: TypeIndex(InValue.GetIndex())
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{
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if (GetIndex() != INDEX_NONE) FHelper::MoveConstructFuncs[InValue.GetIndex()](&Value, &InValue.Value);
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}
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template <size_t I, typename... ArgTypes> requires (I < AlternativeSize)
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&& TIsConstructible<typename TAlternativeType<I>::Type, ArgTypes...>::Value
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constexpr explicit TVariant(TInPlaceIndex<I>, ArgTypes&&... Args)
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: TypeIndex(I)
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{
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using SelectedType = typename TAlternativeType<I>::Type;
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new(&Value) SelectedType(Forward<ArgTypes>(Args)...);
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}
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template <typename T, typename... ArgTypes> requires (TAlternativeIndex<T>::Value != INDEX_NONE)
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&& TIsConstructible<typename TAlternativeType<TAlternativeIndex<T>::Value>::Type, ArgTypes...>::Value
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constexpr explicit TVariant(TInPlaceType<T>, ArgTypes&&... Args)
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: TVariant(InPlaceIndex<TAlternativeIndex<T>::Value>, Forward<ArgTypes>(Args)...)
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{ }
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template <typename T> requires NAMESPACE_PRIVATE::TVariantSelectedType<typename TRemoveReference<T>::Type, Types...>::Value
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&& (!TIsTInPlaceType<typename TRemoveCVRef<T>::Type>::Value) && (!TIsTInPlaceIndex<typename TRemoveCVRef<T>::Type>::Value)
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&& (!TIsSame<typename TRemoveCVRef<T>::Type, TVariant>::Value)
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constexpr TVariant(T&& InValue) : TVariant(InPlaceType<typename NAMESPACE_PRIVATE::TVariantSelectedType<typename TRemoveReference<T>::Type, Types...>::Type>, Forward<T>(InValue))
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{ }
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constexpr ~TVariant()
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{
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if constexpr (!(true && ... && TIsTriviallyDestructible<Types>::Value)) Reset();
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}
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constexpr TVariant& operator=(const TVariant& InValue) requires (true && ... && (TIsCopyConstructible<Types>::Value && TIsCopyAssignable<Types>::Value))
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{
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if (&InValue == this) return *this;
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if (!InValue.IsValid())
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{
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Reset();
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return *this;
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}
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if (GetIndex() == InValue.GetIndex()) FHelper::CopyAssignFuncs[InValue.GetIndex()](&Value, &InValue.Value);
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else
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{
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Reset();
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FHelper::CopyConstructFuncs[InValue.GetIndex()](&Value, &InValue.Value);
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TypeIndex = InValue.GetIndex();
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}
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return *this;
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}
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constexpr TVariant& operator=(TVariant&& InValue) requires (true && ... && (TIsMoveConstructible<Types>::Value && TIsMoveAssignable<Types>::Value))
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{
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if (&InValue == this) return *this;
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if (!InValue.IsValid())
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{
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Reset();
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return *this;
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}
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if (GetIndex() == InValue.GetIndex()) FHelper::MoveAssignFuncs[InValue.GetIndex()](&Value, &InValue.Value);
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else
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{
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Reset();
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FHelper::MoveConstructFuncs[InValue.GetIndex()](&Value, &InValue.Value);
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TypeIndex = InValue.GetIndex();
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}
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return *this;
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}
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template <typename T> requires NAMESPACE_PRIVATE::TVariantSelectedType<typename TRemoveReference<T>::Type, Types...>::Value
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constexpr TVariant& operator=(T&& InValue)
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{
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using SelectedType = typename NAMESPACE_PRIVATE::TVariantSelectedType<typename TRemoveReference<T>::Type, Types...>::Type;
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if (GetIndex() == TAlternativeIndex<SelectedType>::Value) GetValue<SelectedType>() = Forward<T>(InValue);
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else
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{
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Reset();
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new(&Value) SelectedType(Forward<T>(InValue));
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TypeIndex = TAlternativeIndex<SelectedType>::Value;
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}
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return *this;
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}
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template <size_t I, typename... ArgTypes> requires (I < AlternativeSize)
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&& TIsConstructible<typename TAlternativeType<I>::Type, ArgTypes...>::Value
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constexpr typename TAlternativeType<I>::Type& Emplace(ArgTypes&&... Args)
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{
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Reset();
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using SelectedType = typename TAlternativeType<I>::Type;
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SelectedType* Result = new(&Value) SelectedType(Forward<ArgTypes>(Args)...);
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TypeIndex = I;
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return *Result;
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}
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template <typename T, typename... ArgTypes> requires (TAlternativeIndex<T>::Value != INDEX_NONE)
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&& TIsConstructible<typename TAlternativeType<TAlternativeIndex<T>::Value>::Type, ArgTypes...>::Value
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constexpr T& Emplace(ArgTypes&&... Args)
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{
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return Emplace<TAlternativeIndex<T>::Value>(Forward<ArgTypes>(Args)...);
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}
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constexpr size_t GetIndex() const { return TypeIndex; }
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constexpr bool IsValid() const { return GetIndex() != INDEX_NONE; }
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constexpr explicit operator bool() const { return GetIndex() != INDEX_NONE; }
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template <size_t I> constexpr bool HoldsAlternative() const { return IsValid() ? GetIndex() == I : false; }
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template <typename T> constexpr bool HoldsAlternative() const { return IsValid() ? GetIndex() == TAlternativeIndex<T>::Value : false; }
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constexpr void* GetData() { return &Value; }
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constexpr const void* GetData() const { return &Value; }
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template <size_t I> requires (I < AlternativeSize) constexpr typename TAlternativeType<I>::Type& GetValue() & { checkf(HoldsAlternative<I>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return *reinterpret_cast< TAlternativeType<I>::Type*>(&Value); }
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template <size_t I> requires (I < AlternativeSize) constexpr typename TAlternativeType<I>::Type&& GetValue() && { checkf(HoldsAlternative<I>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return MoveTemp(*reinterpret_cast< TAlternativeType<I>::Type*>(&Value)); }
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template <size_t I> requires (I < AlternativeSize) constexpr const typename TAlternativeType<I>::Type& GetValue() const& { checkf(HoldsAlternative<I>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return *reinterpret_cast<const TAlternativeType<I>::Type*>(&Value); }
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template <size_t I> requires (I < AlternativeSize) constexpr const typename TAlternativeType<I>::Type&& GetValue() const&& { checkf(HoldsAlternative<I>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return MoveTemp(*reinterpret_cast<const TAlternativeType<I>::Type*>(&Value)); }
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template <typename T> requires (TAlternativeIndex<T>::Value != INDEX_NONE) constexpr T& GetValue() & { checkf(HoldsAlternative<T>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return *reinterpret_cast< T*>(&Value); }
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template <typename T> requires (TAlternativeIndex<T>::Value != INDEX_NONE) constexpr T&& GetValue() && { checkf(HoldsAlternative<T>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return MoveTemp(*reinterpret_cast< T*>(&Value)); }
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template <typename T> requires (TAlternativeIndex<T>::Value != INDEX_NONE) constexpr const T& GetValue() const& { checkf(HoldsAlternative<T>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return *reinterpret_cast<const T*>(&Value); }
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template <typename T> requires (TAlternativeIndex<T>::Value != INDEX_NONE) constexpr const T&& GetValue() const&& { checkf(HoldsAlternative<T>(), TEXT("It is an error to call GetValue() on an wrong TVariant. Please either check HoldsAlternative() or use Get(DefaultValue) instead.")); return MoveTemp(*reinterpret_cast<const T*>(&Value)); }
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template <size_t I> requires (I < AlternativeSize) constexpr typename TAlternativeType<I>::Type& Get( typename TAlternativeType<I>::Type& DefaultValue) & { return HoldsAlternative<I>() ? GetValue<I>() : DefaultValue; }
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template <size_t I> requires (I < AlternativeSize) constexpr const typename TAlternativeType<I>::Type& Get(const typename TAlternativeType<I>::Type& DefaultValue) const& { return HoldsAlternative<I>() ? GetValue<I>() : DefaultValue; }
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template <typename T> requires (TAlternativeIndex<T>::Value != INDEX_NONE) constexpr T& Get(T& DefaultValue)& { return HoldsAlternative<T>() ? GetValue<T>() : DefaultValue; }
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template <typename T> requires (TAlternativeIndex<T>::Value != INDEX_NONE) constexpr const T& Get(const T& DefaultValue) const& { return HoldsAlternative<T>() ? GetValue<T>() : DefaultValue; }
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template <typename F> requires (true && ... && TIsInvocable<F, Types>::Value)
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constexpr auto Visit(F&& Func) &
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{
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using ReturnType = typename TCommonType<typename TInvokeResult<F, Types>::Type...>::Type;
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checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
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return ReturnType(NAMESPACE_PRIVATE::TVariantVisitHelper<ReturnType, F, Types...>::VisitLValueFuncs[GetIndex()](Forward<F>(Func), &Value));
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}
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template <typename F> requires (true && ... && TIsInvocable<F, Types>::Value)
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constexpr auto Visit(F&& Func) &&
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{
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using ReturnType = typename TCommonType<typename TInvokeResult<F, Types>::Type...>::Type;
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checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
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return ReturnType(NAMESPACE_PRIVATE::TVariantVisitHelper<ReturnType, F, Types...>::VisitRValueFuncs[GetIndex()](Forward<F>(Func), &Value));
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}
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template <typename F> requires (true && ... && TIsInvocable<F, Types>::Value)
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constexpr auto Visit(F&& Func) const&
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{
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using ReturnType = typename TCommonType<typename TInvokeResult<F, Types>::Type...>::Type;
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checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
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return ReturnType(NAMESPACE_PRIVATE::TVariantVisitHelper<ReturnType, F, Types...>::VisitConstLValueFuncs[GetIndex()](Forward<F>(Func), &Value));
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}
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template <typename F> requires (true && ... && TIsInvocable<F, Types>::Value)
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constexpr auto Visit(F&& Func) const&&
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{
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using ReturnType = typename TCommonType<typename TInvokeResult<F, Types>::Type...>::Type;
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checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
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return ReturnType(NAMESPACE_PRIVATE::TVariantVisitHelper<ReturnType, F, Types...>::VisitConstRValueFuncs[GetIndex()](Forward<F>(Func), &Value));
|
|
}
|
|
|
|
template <typename R, typename F> requires (true && ... && TIsInvocableResult<R, F, Types>::Value)
|
|
constexpr R Visit(F&& Func) &
|
|
{
|
|
checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
|
|
return R(NAMESPACE_PRIVATE::TVariantVisitHelper<R, F, Types...>::VisitLValueFuncs[GetIndex()](Forward<F>(Func), &Value));
|
|
}
|
|
|
|
template <typename R, typename F> requires (true && ... && TIsInvocableResult<R, F, Types>::Value)
|
|
constexpr R Visit(F&& Func) &&
|
|
{
|
|
checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
|
|
return R(NAMESPACE_PRIVATE::TVariantVisitHelper<R, F, Types...>::VisitRValueFuncs[GetIndex()](Forward<F>(Func), &Value));
|
|
}
|
|
|
|
template <typename R, typename F> requires (true && ... && TIsInvocableResult<R, F, Types>::Value)
|
|
constexpr R Visit(F&& Func) const&
|
|
{
|
|
checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
|
|
return R(NAMESPACE_PRIVATE::TVariantVisitHelper<R, F, Types...>::VisitConstLValueFuncs[GetIndex()](Forward<F>(Func), &Value));
|
|
}
|
|
|
|
template <typename R, typename F> requires (true && ... && TIsInvocableResult<R, F, Types>::Value)
|
|
constexpr R Visit(F&& Func) const&&
|
|
{
|
|
checkf(IsValid(), "It is an error to call Visit() on an wrong TVariant. Please either check IsValid().");
|
|
return R(NAMESPACE_PRIVATE::TVariantVisitHelper<R, F, Types...>::VisitConstRValueFuncs[GetIndex()](Forward<F>(Func), &Value));
|
|
}
|
|
|
|
constexpr size_t GetTypeHash() const requires (true && ... && CHashable<Types>)
|
|
{
|
|
if (!IsValid()) return NAMESPACE_REDCRAFT::GetTypeHash(nullptr);
|
|
return Visit([](auto&& A) { return NAMESPACE_REDCRAFT::GetTypeHash(A); });
|
|
}
|
|
|
|
constexpr void Reset()
|
|
{
|
|
if (GetIndex() == INDEX_NONE) return;
|
|
|
|
if constexpr (!(true && ... && TIsTriviallyDestructible<Types>::Value))
|
|
{
|
|
FHelper::DestroyFuncs[GetIndex()](&Value);
|
|
}
|
|
|
|
TypeIndex = INDEX_NONE;
|
|
}
|
|
|
|
private:
|
|
|
|
using FHelper = NAMESPACE_PRIVATE::TVariantHelper<Types...>;
|
|
|
|
TAlignedUnion<1, Types...>::Type Value;
|
|
size_t TypeIndex;
|
|
|
|
friend constexpr bool operator==(const TVariant& LHS, const TVariant& RHS) requires (true && ... && CEqualityComparable<Types>)
|
|
{
|
|
if (LHS.GetIndex() != RHS.GetIndex()) return false;
|
|
if (LHS.IsValid() == false) return true;
|
|
return FHelper::EqualityOperatorFuncs[LHS.GetIndex()](&LHS.Value, &RHS.Value);
|
|
}
|
|
|
|
friend constexpr bool operator!=(const TVariant& LHS, const TVariant& RHS) requires (true && ... && CEqualityComparable<Types>)
|
|
{
|
|
if (LHS.GetIndex() != RHS.GetIndex()) return true;
|
|
if (LHS.IsValid() == false) return false;
|
|
return FHelper::InequalityOperatorFuncs[LHS.GetIndex()](&LHS.Value, &RHS.Value);
|
|
}
|
|
|
|
};
|
|
|
|
template <typename T, typename... Types> requires (!TIsSame<T, TVariant<Types...>>::Value) && CEqualityComparable<T>
|
|
constexpr bool operator==(const TVariant<Types...>& LHS, const T& RHS)
|
|
{
|
|
return LHS.template HoldsAlternative<T>() ? LHS.template GetValue<T>() == RHS : false;
|
|
}
|
|
|
|
template <typename T, typename... Types> requires (!TIsSame<T, TVariant<Types...>>::Value) && CEqualityComparable<T>
|
|
constexpr bool operator!=(const TVariant<Types...>& LHS, const T& RHS)
|
|
{
|
|
return LHS.template HoldsAlternative<T>() ? LHS.template GetValue<T>() != RHS : true;
|
|
}
|
|
|
|
template <typename T, typename... Types> requires (!TIsSame<T, TVariant<Types...>>::Value) && CEqualityComparable<T>
|
|
constexpr bool operator==(const T& LHS, const TVariant<Types...>& RHS)
|
|
{
|
|
return RHS.template HoldsAlternative<T>() ? LHS == RHS.template GetValue<T>() : false;
|
|
}
|
|
|
|
template <typename T, typename... Types> requires (!TIsSame<T, TVariant<Types...>>::Value) && CEqualityComparable<T>
|
|
constexpr bool operator!=(const T& LHS, const TVariant<Types...>& RHS)
|
|
{
|
|
return RHS.template HoldsAlternative<T>() ? LHS != RHS.template GetValue<T>() : true;
|
|
}
|
|
|
|
template <typename... Types>
|
|
constexpr bool operator==(const TVariant<Types...>& LHS, FInvalid)
|
|
{
|
|
return !LHS.IsValid();
|
|
}
|
|
|
|
template <typename... Types>
|
|
constexpr bool operator!=(const TVariant<Types...>& LHS, FInvalid)
|
|
{
|
|
return LHS.IsValid();
|
|
}
|
|
|
|
template <typename... Types>
|
|
constexpr bool operator==(FInvalid, const TVariant<Types...>& RHS)
|
|
{
|
|
return !RHS.IsValid();
|
|
}
|
|
|
|
template <typename... Types>
|
|
constexpr bool operator!=(FInvalid, const TVariant<Types...>& RHS)
|
|
{
|
|
return RHS.IsValid();
|
|
}
|
|
|
|
template <typename... Types> requires (true && ... && (TIsMoveConstructible<Types>::Value && TIsSwappable<Types>::Value))
|
|
constexpr void Swap(TVariant<Types...>& A, TVariant<Types...>& B)
|
|
{
|
|
if (!A && !B) return;
|
|
|
|
if (A && !B)
|
|
{
|
|
B = MoveTemp(A);
|
|
A.Reset();
|
|
return;
|
|
}
|
|
|
|
if (B && !A)
|
|
{
|
|
A = MoveTemp(B);
|
|
B.Reset();
|
|
return;
|
|
}
|
|
|
|
TVariant<Types...> Temp = MoveTemp(A);
|
|
A = MoveTemp(B);
|
|
B = MoveTemp(Temp);
|
|
}
|
|
|
|
template <typename T > struct TIsTVariant : FFalse { };
|
|
template <typename... Types> struct TIsTVariant<TVariant<Types...>> : FTrue { };
|
|
|
|
template <typename VariantType> requires TIsTVariant<typename TRemoveCVRef<VariantType>::Type>::Value
|
|
struct TVariantAlternativeSize : TConstant<size_t, VariantType::AlternativeSize> { };
|
|
|
|
template <size_t I, typename VariantType> requires TIsTVariant<typename TRemoveCVRef<VariantType>::Type>::Value
|
|
struct TVariantAlternativeType { using Type = typename TCopyCV<typename TRemoveReference<VariantType>::Type, typename TRemoveCVRef<VariantType>::Type::template TAlternativeType<I>::Type>::Type; };
|
|
|
|
template <typename T, typename VariantType> requires TIsTVariant<typename TRemoveCVRef<VariantType>::Type>::Value
|
|
struct TVariantAlternativeIndex : VariantType::template TAlternativeIndex<T> { };
|
|
|
|
NAMESPACE_MODULE_END(Utility)
|
|
NAMESPACE_MODULE_END(Redcraft)
|
|
NAMESPACE_REDCRAFT_END
|