499 lines
22 KiB
C++
499 lines
22 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/Utility.h"
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#include "Templates/TypeHash.h"
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#include "TypeTraits/TypeTraits.h"
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#include "Templates/Meta.h"
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#include "Memory/MemoryOperator.h"
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#include "Miscellaneous/Compare.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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template <typename... Ts> requires (sizeof...(Ts) > 0 && (true && ... && CDestructible<Ts>))
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class TVariant;
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NAMESPACE_PRIVATE_BEGIN
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template <typename T > struct TIsTVariant : FFalse { };
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template <typename... Ts> struct TIsTVariant<TVariant<Ts...>> : FTrue { };
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template <typename VariantType>
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struct TVariantNumImpl;
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template <typename... Ts>
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struct TVariantNumImpl<TVariant<Ts...>> : TConstant<size_t, Meta::TSize<TTypeSequence<Ts...>>> { };
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template <typename T, typename VariantType>
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struct TVariantIndexImpl;
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template <typename T, typename... Ts>
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struct TVariantIndexImpl<T, TVariant<Ts...>> : TConstant<size_t, Meta::TIndex<T, TTypeSequence<Ts...>>> { };
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template <size_t I, typename VariantType>
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struct TVariantAlternativeImpl;
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template <size_t I, typename... Ts>
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struct TVariantAlternativeImpl<I, TVariant<Ts...>>
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{
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using Type = Meta::TType<I, TTypeSequence<Ts...>>;
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};
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template <typename T, typename TSequence>
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struct TVariantOverloadType
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{
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using FrontType = Meta::TFront<TSequence>;
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using NextSequence = Meta::TPop<TSequence>;
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using NextUniqueSequence = typename TVariantOverloadType<T, NextSequence>::Type;
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// T_i x[] = { Forward<T>(t) };
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static constexpr bool bConditional = requires { DeclVal<void(FrontType(&&)[1])>()({ DeclVal<T>() }); };
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using Type = TConditional<bConditional, Meta::TPush<FrontType, NextUniqueSequence>, NextUniqueSequence>;
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};
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template <typename T>
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struct TVariantOverloadType<T, TTypeSequence<>>
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{
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using Type = TTypeSequence<>;
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};
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template <typename T, typename... Ts>
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using TVariantSelectedType = Meta::TOverloadResolution<T, typename NAMESPACE_PRIVATE::TVariantOverloadType<T, TTypeSequence<Ts...>>::Type>;
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NAMESPACE_PRIVATE_END
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template <typename T>
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concept CTVariant = NAMESPACE_PRIVATE::TIsTVariant<TRemoveCV<T>>::Value;
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template <CTVariant T>
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inline constexpr size_t TVariantNum = NAMESPACE_PRIVATE::TVariantNumImpl<TRemoveCV<T>>::Value;
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template <typename T, CTVariant U>
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inline constexpr size_t TVariantIndex = NAMESPACE_PRIVATE::TVariantIndexImpl<T, TRemoveCV<U>>::Value;
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template <size_t I, CTVariant U>
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using TVariantAlternative = TCopyCV<U, typename NAMESPACE_PRIVATE::TVariantAlternativeImpl<I, TRemoveCV<U>>::Type>;
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template <typename... Ts> requires (sizeof...(Ts) > 0 && (true && ... && CDestructible<Ts>))
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class TVariant
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{
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public:
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FORCEINLINE constexpr TVariant() : TypeIndex(0xFF) { };
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FORCEINLINE constexpr TVariant(FInvalid) : TVariant() { };
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FORCEINLINE constexpr TVariant(const TVariant& InValue) requires (true && ... && CTriviallyCopyConstructible<Ts>) = default;
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FORCEINLINE constexpr TVariant(const TVariant& InValue) requires ((true && ... && CCopyConstructible<Ts>) && !(true && ... && CTriviallyCopyConstructible<Ts>))
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: TypeIndex(static_cast<uint8>(InValue.GetIndex()))
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{
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if (IsValid()) CopyConstructImpl[InValue.GetIndex()](&Value, &InValue.Value);
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}
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FORCEINLINE constexpr TVariant(TVariant&& InValue) requires (true && ... && CTriviallyMoveConstructible<Ts>) = default;
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FORCEINLINE constexpr TVariant(TVariant&& InValue) requires ((true && ... && CMoveConstructible<Ts>) && !(true && ... && CTriviallyMoveConstructible<Ts>))
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: TypeIndex(static_cast<uint8>(InValue.GetIndex()))
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{
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if (IsValid()) MoveConstructImpl[InValue.GetIndex()](&Value, &InValue.Value);
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}
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template <size_t I, typename... ArgTypes> requires (I < sizeof...(Ts)
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&& CConstructibleFrom<TVariantAlternative<I, TVariant<Ts...>>, ArgTypes...>)
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FORCEINLINE constexpr explicit TVariant(TInPlaceIndex<I>, ArgTypes&&... Args)
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: TypeIndex(I)
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{
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using SelectedType = TVariantAlternative<I, TVariant<Ts...>>;
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new (&Value) SelectedType(Forward<ArgTypes>(Args)...);
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}
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template <typename T, typename... ArgTypes> requires (CConstructibleFrom<T, ArgTypes...>)
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FORCEINLINE constexpr explicit TVariant(TInPlaceType<T>, ArgTypes&&... Args)
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: TVariant(InPlaceIndex<TVariantIndex<T, TVariant<Ts...>>>, Forward<ArgTypes>(Args)...)
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{ }
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template <typename T> requires (requires { typename NAMESPACE_PRIVATE::TVariantSelectedType<T, Ts...>; }
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&& !CTInPlaceType<TRemoveCVRef<T>> && !CTInPlaceIndex<TRemoveCVRef<T>>
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&& !CSameAs<TVariant, TRemoveCVRef<T>>)
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FORCEINLINE constexpr TVariant(T&& InValue) : TVariant(InPlaceType<NAMESPACE_PRIVATE::TVariantSelectedType<T, Ts...>>, Forward<T>(InValue))
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{ }
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FORCEINLINE constexpr ~TVariant() requires (true && ... && CTriviallyDestructible<Ts>) = default;
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FORCEINLINE constexpr ~TVariant() requires (!(true && ... && CTriviallyDestructible<Ts>))
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{
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Reset();
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}
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FORCEINLINE constexpr TVariant& operator=(const TVariant& InValue) requires (true && ... && (CTriviallyCopyConstructible<Ts> && CTriviallyCopyAssignable<Ts>)) = default;
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constexpr TVariant& operator=(const TVariant& InValue) requires ((true && ... && (CCopyConstructible<Ts> && CCopyAssignable<Ts>))
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&& !(true && ... && (CTriviallyCopyConstructible<Ts> && CTriviallyCopyAssignable<Ts>)))
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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()) CopyAssignImpl[InValue.GetIndex()](&Value, &InValue.Value);
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else
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{
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Reset();
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CopyConstructImpl[InValue.GetIndex()](&Value, &InValue.Value);
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TypeIndex = static_cast<uint8>(InValue.GetIndex());
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}
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return *this;
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}
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FORCEINLINE constexpr TVariant& operator=(TVariant&& InValue) requires (true && ... && (CTriviallyMoveConstructible<Ts> && CTriviallyMoveAssignable<Ts>)) = default;
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constexpr TVariant& operator=(TVariant&& InValue) requires ((true && ... && (CMoveConstructible<Ts> && CMoveAssignable<Ts>))
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&& !(true && ... && (CTriviallyMoveConstructible<Ts> && CTriviallyMoveAssignable<Ts>)))
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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()) MoveAssignImpl[InValue.GetIndex()](&Value, &InValue.Value);
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else
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{
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Reset();
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MoveConstructImpl[InValue.GetIndex()](&Value, &InValue.Value);
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TypeIndex = static_cast<uint8>(InValue.GetIndex());
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}
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return *this;
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}
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template <typename T> requires (requires { typename NAMESPACE_PRIVATE::TVariantSelectedType<T, Ts...>; })
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FORCEINLINE constexpr TVariant& operator=(T&& InValue)
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{
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using SelectedType = NAMESPACE_PRIVATE::TVariantSelectedType<T, Ts...>;
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if (GetIndex() == TVariantIndex<SelectedType, TVariant<Ts...>>) 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 = TVariantIndex<SelectedType, TVariant<Ts...>>;
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}
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return *this;
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}
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friend constexpr bool operator==(const TVariant& LHS, const TVariant& RHS) requires (true && ... && CEqualityComparable<Ts>)
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{
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if (LHS.GetIndex() != RHS.GetIndex()) return false;
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if (LHS.IsValid() == false) return true;
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using FCompareImpl = bool(*)(const void*, const void*);
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constexpr FCompareImpl CompareImpl[] = { [](const void* LHS, const void* RHS) -> bool { return *reinterpret_cast<const Ts*>(LHS) == *reinterpret_cast<const Ts*>(RHS); }... };
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return CompareImpl[LHS.GetIndex()](&LHS.Value, &RHS.Value);
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}
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friend constexpr partial_ordering operator<=>(const TVariant& LHS, const TVariant& RHS) requires (true && ... && CSynthThreeWayComparable<Ts>)
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{
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if (LHS.GetIndex() != RHS.GetIndex()) return partial_ordering::unordered;
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if (LHS.IsValid() == false) return partial_ordering::equivalent;
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using FCompareImpl = partial_ordering(*)(const void*, const void*);
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constexpr FCompareImpl CompareImpl[] = { [](const void* LHS, const void* RHS) -> partial_ordering { return SynthThreeWayCompare(*reinterpret_cast<const Ts*>(LHS), *reinterpret_cast<const Ts*>(RHS)); }...};
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return CompareImpl[LHS.GetIndex()](&LHS.Value, &RHS.Value);
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}
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template <typename T> requires (!CSameAs<TVariant, T> && CEqualityComparable<T>)
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FORCEINLINE constexpr bool operator==(const T& InValue) const&
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{
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return HoldsAlternative<T>() ? GetValue<T>() == InValue : false;
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}
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template <typename T> requires (!CSameAs<TVariant, T> && CEqualityComparable<T>)
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FORCEINLINE constexpr partial_ordering operator<=>(const T& InValue) const&
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{
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return HoldsAlternative<T>() ? SynthThreeWayCompare(GetValue<T>(), InValue) : partial_ordering::unordered;
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}
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FORCEINLINE constexpr bool operator==(FInvalid) const& { return !IsValid(); }
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template <size_t I, typename... ArgTypes> requires (I < sizeof...(Ts)
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&& CConstructibleFrom<TVariantAlternative<I, TVariant<Ts...>>, ArgTypes...>)
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FORCEINLINE constexpr TVariantAlternative<I, TVariant<Ts...>>& Emplace(ArgTypes&&... Args)
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{
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Reset();
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using SelectedType = TVariantAlternative<I, TVariant<Ts...>>;
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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 (CConstructibleFrom<T, ArgTypes...>)
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FORCEINLINE constexpr T& Emplace(ArgTypes&&... Args)
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{
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return Emplace<TVariantIndex<T, TVariant<Ts...>>>(Forward<ArgTypes>(Args)...);
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}
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FORCEINLINE constexpr const type_info& GetTypeInfo() const { return IsValid() ? *TypeInfos[GetIndex()] : typeid(void); }
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FORCEINLINE constexpr size_t GetIndex() const { return TypeIndex != 0xFF ? TypeIndex : INDEX_NONE; }
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FORCEINLINE constexpr bool IsValid() const { return TypeIndex != 0xFF; }
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FORCEINLINE constexpr explicit operator bool() const { return TypeIndex != 0xFF; }
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template <size_t I> FORCEINLINE constexpr bool HoldsAlternative() const { return IsValid() ? GetIndex() == I : false; }
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template <typename T> FORCEINLINE constexpr bool HoldsAlternative() const { return IsValid() ? GetIndex() == TVariantIndex<T, TVariant<Ts...>> : false; }
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template <size_t I> requires (I < sizeof...(Ts)) FORCEINLINE constexpr decltype(auto) 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< TVariantAlternative<I, TVariant<Ts...>>*>(&Value); }
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template <size_t I> requires (I < sizeof...(Ts)) FORCEINLINE constexpr decltype(auto) 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< TVariantAlternative<I, TVariant<Ts...>>*>(&Value)); }
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template <size_t I> requires (I < sizeof...(Ts)) FORCEINLINE constexpr decltype(auto) 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 TVariantAlternative<I, TVariant<Ts...>>*>(&Value); }
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template <size_t I> requires (I < sizeof...(Ts)) FORCEINLINE constexpr decltype(auto) 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 TVariantAlternative<I, TVariant<Ts...>>*>(&Value)); }
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template <typename T> FORCEINLINE constexpr decltype(auto) 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> FORCEINLINE constexpr decltype(auto) 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> FORCEINLINE constexpr decltype(auto) 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> FORCEINLINE constexpr decltype(auto) 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 < sizeof...(Ts)) FORCEINLINE constexpr decltype(auto) Get( TVariantAlternative<I, TVariant<Ts...>>& DefaultValue) & { return HoldsAlternative<I>() ? GetValue<I>() : DefaultValue; }
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template <size_t I> requires (I < sizeof...(Ts)) FORCEINLINE constexpr decltype(auto) Get(const TVariantAlternative<I, TVariant<Ts...>>& DefaultValue) const& { return HoldsAlternative<I>() ? GetValue<I>() : DefaultValue; }
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template <typename T> FORCEINLINE constexpr decltype(auto) Get( T& DefaultValue) & { return HoldsAlternative<T>() ? GetValue<T>() : DefaultValue; }
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template <typename T> FORCEINLINE constexpr decltype(auto) Get(const T& DefaultValue) const& { return HoldsAlternative<T>() ? GetValue<T>() : DefaultValue; }
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FORCEINLINE constexpr void Reset()
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{
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if (GetIndex() == INDEX_NONE) return;
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if constexpr (!(true && ... && CTriviallyDestructible<Ts>))
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{
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DestroyImpl[GetIndex()](&Value);
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}
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TypeIndex = static_cast<uint8>(INDEX_NONE);
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}
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friend FORCEINLINE constexpr size_t GetTypeHash(const TVariant& A) requires (true && ... && CHashable<Ts>)
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{
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if (!A.IsValid()) return 114514;
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using FHashImpl = size_t(*)(const void*);
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constexpr FHashImpl HashImpl[] = { [](const void* This) -> size_t { return GetTypeHash(*reinterpret_cast<const Ts*>(This)); }... };
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return HashCombine(GetTypeHash(A.GetIndex()), HashImpl[A.GetIndex()](&A.Value));
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}
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friend constexpr void Swap(TVariant& A, TVariant& B) requires (true && ... && (CMoveConstructible<Ts> && CSwappable<Ts>))
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{
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if (!A.IsValid() && !B.IsValid()) return;
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if (A.IsValid() && !B.IsValid())
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{
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B = MoveTemp(A);
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A.Reset();
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}
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else if (!A.IsValid() && B.IsValid())
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{
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A = MoveTemp(B);
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B.Reset();
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}
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else if (A.GetIndex() == B.GetIndex())
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{
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using FSwapImpl = void(*)(void*, void*);
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constexpr FSwapImpl SwapImpl[] = { [](void* A, void* B) { Swap(*reinterpret_cast<Ts*>(A), *reinterpret_cast<Ts*>(B)); }... };
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SwapImpl[A.GetIndex()](&A.Value, &B.Value);
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}
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else
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{
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TVariant Temp = MoveTemp(A);
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A = MoveTemp(B);
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B = MoveTemp(Temp);
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}
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}
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private:
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static constexpr const type_info* TypeInfos[] = { &typeid(Ts)... };
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using FCopyConstructImpl = void(*)(void*, const void*);
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using FMoveConstructImpl = void(*)(void*, void*);
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using FCopyAssignImpl = void(*)(void*, const void*);
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using FMoveAssignImpl = void(*)(void*, void*);
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using FDestroyImpl = void(*)(void* );
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static constexpr FCopyConstructImpl CopyConstructImpl[] = { [](void* A, const void* B) { if constexpr (requires(Ts* A, const Ts* B) { Memory::CopyConstruct (A, B); }) Memory::CopyConstruct (reinterpret_cast<Ts*>(A), reinterpret_cast<const Ts*>(B)); else checkf(false, TEXT("The type '%s' is not copy constructible."), typeid(Ts).name()); }... };
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static constexpr FMoveConstructImpl MoveConstructImpl[] = { [](void* A, void* B) { if constexpr (requires(Ts* A, Ts* B) { Memory::MoveConstruct (A, B); }) Memory::MoveConstruct (reinterpret_cast<Ts*>(A), reinterpret_cast< Ts*>(B)); else checkf(false, TEXT("The type '%s' is not move constructible."), typeid(Ts).name()); }... };
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static constexpr FCopyAssignImpl CopyAssignImpl[] = { [](void* A, const void* B) { if constexpr (requires(Ts* A, const Ts* B) { Memory::CopyAssign (A, B); }) Memory::CopyAssign (reinterpret_cast<Ts*>(A), reinterpret_cast<const Ts*>(B)); else checkf(false, TEXT("The type '%s' is not copy assignable."), typeid(Ts).name()); }... };
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static constexpr FMoveAssignImpl MoveAssignImpl[] = { [](void* A, void* B) { if constexpr (requires(Ts* A, Ts* B) { Memory::MoveAssign (A, B); }) Memory::MoveAssign (reinterpret_cast<Ts*>(A), reinterpret_cast< Ts*>(B)); else checkf(false, TEXT("The type '%s' is not move assignable."), typeid(Ts).name()); }... };
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static constexpr FDestroyImpl DestroyImpl[] = { [](void* A ) { if constexpr (requires(Ts* A ) { Memory::Destruct (A ); }) Memory::Destruct (reinterpret_cast<Ts*>(A) ); else checkf(false, TEXT("The type '%s' is not destructible."), typeid(Ts).name()); }... };
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TAlignedUnion<1, Ts...> Value;
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uint8 TypeIndex;
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};
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NAMESPACE_PRIVATE_BEGIN
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template <typename F, typename... VariantTypes>
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struct TVariantVisitImpl
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{
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struct GetTotalNum
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{
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FORCEINLINE static constexpr size_t Do()
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{
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if (sizeof...(VariantTypes) == 0) return 0;
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constexpr size_t VariantNums[] = { TVariantNum<TRemoveReference<VariantTypes>>... };
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size_t Result = 1;
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for (size_t Index = 0; Index < sizeof...(VariantTypes); ++Index)
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{
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Result *= VariantNums[Index];
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}
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return Result;
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};
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};
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struct EncodeIndices
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{
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FORCEINLINE static constexpr size_t Do(initializer_list<size_t> Indices)
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{
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constexpr size_t VariantNums[] = { TVariantNum<TRemoveReference<VariantTypes>>... };
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size_t Result = 0;
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for (size_t Index = 0; Index < sizeof...(VariantTypes); ++Index)
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{
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Result *= VariantNums[Index];
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Result += GetData(Indices)[Index];
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}
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return Result;
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};
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};
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struct DecodeExtent
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{
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FORCEINLINE static constexpr size_t Do(size_t EncodedIndex, size_t Extent)
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{
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constexpr size_t VariantNums[] = { TVariantNum<TRemoveReference<VariantTypes>>... };
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for (size_t Index = Extent + 1; Index < sizeof...(VariantTypes); ++Index)
|
|
{
|
|
EncodedIndex /= VariantNums[Index];
|
|
}
|
|
|
|
return EncodedIndex % VariantNums[Extent];
|
|
};
|
|
};
|
|
|
|
template <size_t EncodedIndex, typename>
|
|
struct InvokeEncoded;
|
|
|
|
template <size_t EncodedIndex, size_t... ExtentIndices>
|
|
struct InvokeEncoded<EncodedIndex, TIndexSequence<ExtentIndices...>>
|
|
{
|
|
FORCEINLINE static constexpr decltype(auto) Do(F&& Func, VariantTypes&&... Variants)
|
|
{
|
|
return Invoke(Forward<F>(Func), Forward<VariantTypes>(Variants).template GetValue<DecodeExtent::Do(EncodedIndex, ExtentIndices)>()...);
|
|
}
|
|
|
|
template <typename Ret>
|
|
struct Result
|
|
{
|
|
FORCEINLINE static constexpr Ret Do(F&& Func, VariantTypes&&... Variants)
|
|
{
|
|
return InvokeResult<Ret>(Forward<F>(Func), Forward<VariantTypes>(Variants).template GetValue<DecodeExtent::Do(EncodedIndex, ExtentIndices)>()...);
|
|
}
|
|
};
|
|
};
|
|
|
|
template <typename>
|
|
struct InvokeVariant;
|
|
|
|
template <size_t... EncodedIndices>
|
|
struct InvokeVariant<TIndexSequence<EncodedIndices...>>
|
|
{
|
|
FORCEINLINE static constexpr decltype(auto) Do(F&& Func, VariantTypes&&... Variants)
|
|
{
|
|
using ExtentIndices = TIndexSequenceFor<VariantTypes...>;
|
|
|
|
using ResultType = TCommonType<decltype(InvokeEncoded<EncodedIndices, ExtentIndices>::Do(Forward<F>(Func), Forward<VariantTypes>(Variants)...))...>;
|
|
|
|
using InvokeImplType = ResultType(*)(F&&, VariantTypes&&...);
|
|
|
|
constexpr InvokeImplType InvokeImpl[] = { InvokeEncoded<EncodedIndices, ExtentIndices>::template Result<ResultType>::Do... };
|
|
|
|
return InvokeImpl[EncodeIndices::Do({ Variants.GetIndex()... })](Forward<F>(Func), Forward<VariantTypes>(Variants)...);
|
|
}
|
|
|
|
template <typename Ret>
|
|
struct Result
|
|
{
|
|
FORCEINLINE static constexpr Ret Do(F&& Func, VariantTypes&&... Variants)
|
|
{
|
|
using ExtentIndices = TIndexSequenceFor<VariantTypes...>;
|
|
|
|
using InvokeImplType = Ret(*)(F&&, VariantTypes&&...);
|
|
|
|
constexpr InvokeImplType InvokeImpl[] = { InvokeEncoded<EncodedIndices, ExtentIndices>::template Result<Ret>::Do... };
|
|
|
|
return InvokeImpl[EncodeIndices::Do({ Variants.GetIndex()... })](Forward<F>(Func), Forward<VariantTypes>(Variants)...);
|
|
}
|
|
};
|
|
};
|
|
|
|
FORCEINLINE static constexpr decltype(auto) Do(F&& Func, VariantTypes&&... Variants)
|
|
{
|
|
return InvokeVariant<TMakeIndexSequence<GetTotalNum::Do()>>::Do(Forward<F>(Func), Forward<VariantTypes>(Variants)...);
|
|
}
|
|
|
|
template <typename Ret>
|
|
struct Result
|
|
{
|
|
FORCEINLINE static constexpr Ret Do(F&& Func, VariantTypes&&... Variants)
|
|
{
|
|
return InvokeVariant<TMakeIndexSequence<GetTotalNum::Do()>>::template Result<Ret>::Do(Forward<F>(Func), Forward<VariantTypes>(Variants)...);
|
|
}
|
|
};
|
|
};
|
|
|
|
NAMESPACE_PRIVATE_END
|
|
|
|
template <typename F, typename FirstVariantType, typename... VariantTypes>
|
|
requires (CTVariant<TRemoveReference<FirstVariantType>> && (true && ... && CTVariant<TRemoveReference<VariantTypes>>))
|
|
constexpr decltype(auto) Visit(F&& Func, FirstVariantType&& FirstVariant, VariantTypes&&... Variants)
|
|
{
|
|
checkf((true && ... && Variants.IsValid()), TEXT("It is an error to call Visit() on an wrong TVariant. Please either check IsValid()."));
|
|
return NAMESPACE_PRIVATE::TVariantVisitImpl<F, FirstVariantType, VariantTypes...>::Do(Forward<F>(Func), Forward<FirstVariantType>(FirstVariant), Forward<VariantTypes>(Variants)...);
|
|
}
|
|
|
|
template <typename Ret, typename F, typename FirstVariantType, typename... VariantTypes>
|
|
requires (CTVariant<TRemoveReference<FirstVariantType>> && (true && ... && CTVariant<TRemoveReference<VariantTypes>>))
|
|
constexpr Ret Visit(F&& Func, FirstVariantType&& FirstVariant, VariantTypes&&... Variants)
|
|
{
|
|
checkf((true && ... && Variants.IsValid()), TEXT("It is an error to call Visit() on an wrong TVariant. Please either check IsValid()."));
|
|
return NAMESPACE_PRIVATE::TVariantVisitImpl<F, FirstVariantType, VariantTypes...>::template Result<Ret>::Do(Forward<F>(Func), Forward<FirstVariantType>(FirstVariant), Forward<VariantTypes>(Variants)...);
|
|
}
|
|
|
|
NAMESPACE_MODULE_END(Utility)
|
|
NAMESPACE_MODULE_END(Redcraft)
|
|
NAMESPACE_REDCRAFT_END
|