492 lines
22 KiB
C++
492 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 "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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// This class is to avoid conflicting with sizeof...(Ts) > 0 constraints when using TVariant<> in tool templates
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template <typename... Ts>
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struct TVariantProxy { };
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template <typename TupleType>
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struct TVariantNumImpl;
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template <typename... Ts>
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struct TVariantNumImpl<TVariant<Ts...>> : TConstant<size_t, sizeof...(Ts)> { };
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template <typename... Ts>
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struct TVariantNumImpl<const TVariant<Ts...>> : TConstant<size_t, sizeof...(Ts)> { };
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template <typename... Ts>
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struct TVariantNumImpl<volatile TVariant<Ts...>> : TConstant<size_t, sizeof...(Ts)> { };
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template <typename... Ts>
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struct TVariantNumImpl<const volatile TVariant<Ts...>> : TConstant<size_t, sizeof...(Ts)> { };
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template <typename T, typename TupleType>
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struct TVariantIndexImpl;
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template <typename T, typename U, typename... Ts>
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struct TVariantIndexImpl<T, TVariantProxy<U, Ts...>> : TConstant<size_t, TVariantIndexImpl<T, TVariantProxy<Ts...>>::Value + 1>
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{
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static_assert(sizeof...(Ts) != 0, "Non-existent types in variant");
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};
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template <typename T, typename... Ts>
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struct TVariantIndexImpl<T, TVariantProxy<T, Ts...>> : TConstant<size_t, 0>
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{
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static_assert((true && ... && !CSameAs<T, Ts>), "Duplicate type in variant");
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};
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template <typename T>
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struct TVariantIndexImpl<T, TVariantProxy<>> : TConstant<size_t, INDEX_NONE> { };
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template <typename T, typename... Ts>
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struct TVariantIndexImpl<T, TVariant<Ts...>> : TVariantIndexImpl<T, TVariantProxy<Ts...>> { };
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template <typename T, typename... Ts>
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struct TVariantIndexImpl<T, const TVariant<Ts...>> : TVariantIndexImpl<T, TVariant<Ts...>> { };
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template <typename T, typename... Ts>
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struct TVariantIndexImpl<T, volatile TVariant<Ts...>> : TVariantIndexImpl<T, TVariant<Ts...>> { };
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template <typename T, typename... Ts>
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struct TVariantIndexImpl<T, const volatile TVariant<Ts...>> : TVariantIndexImpl<T, TVariant<Ts...>> { };
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template <size_t I, typename TupleType>
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struct TVariantAlternativeImpl;
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template <size_t I, typename T, typename... Ts>
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struct TVariantAlternativeImpl<I, TVariantProxy<T, Ts...>>
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{
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static_assert(I < sizeof...(Ts) + 1, "Invalid index in variant");
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using Type = TVariantAlternativeImpl<I - 1, TVariantProxy<Ts...>>::Type;
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};
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template <typename T, typename... Ts>
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struct TVariantAlternativeImpl<0, TVariantProxy<T, Ts...>> { using Type = T; };
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template <size_t I, typename... Ts>
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struct TVariantAlternativeImpl<I, TVariantProxy<Ts...>> { };
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template <>
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struct TVariantAlternativeImpl<0, TVariantProxy<>> { };
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template <size_t I, typename... Ts>
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struct TVariantAlternativeImpl<I, TVariant<Ts...>> : TVariantAlternativeImpl<I, TVariantProxy<Ts...>> { };
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template <size_t I, typename... Ts>
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struct TVariantAlternativeImpl<I, const TVariant<Ts...>> { using Type = TAddConst<typename TVariantAlternativeImpl<I, TVariant<Ts...>>::Type>; };
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template <size_t I, typename... Ts>
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struct TVariantAlternativeImpl<I, volatile TVariant<Ts...>> { using Type = TAddVolatile<typename TVariantAlternativeImpl<I, TVariant<Ts...>>::Type>; };
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template <size_t I, typename... Ts>
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struct TVariantAlternativeImpl<I, const volatile TVariant<Ts...>> { using Type = TAddCV<typename TVariantAlternativeImpl<I, TVariant<Ts...>>::Type>; };
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template <typename T, typename... Ts>
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struct TVariantSelectedType;
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template <typename T, typename U, typename... Ts>
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struct TVariantSelectedType<T, U, Ts...>
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{
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using TypeAlternativeA = TConditional<CConstructibleFrom<U, T&&>, U, void>;
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using TypeAlternativeB = typename TVariantSelectedType<T, Ts...>::Type;
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using Type = TConditional<CSameAs<TRemoveCVRef<TypeAlternativeA>, void>, TypeAlternativeB,
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TConditional<CSameAs<TRemoveCVRef<TypeAlternativeB>, void>, TypeAlternativeA,
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TConditional<CSameAs<TRemoveCVRef<TypeAlternativeB>, TRemoveCVRef<T>>, TypeAlternativeB, TypeAlternativeA>>>;
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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 = CSameAs<TRemoveCVRef<Type>, void> ? 0 :
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CSameAs<TRemoveCVRef<TypeAlternativeA>, TRemoveCVRef<TypeAlternativeB>> ? 2 :
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CSameAs<TRemoveCVRef< Type>, TRemoveCVRef< T>> ? 1 :
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!CSameAs<TRemoveCVRef<TypeAlternativeA>, void> && !CSameAs<TypeAlternativeB, void> ? 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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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<T>::Value;
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template <typename T, CTVariant U>
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inline constexpr size_t TVariantIndex = NAMESPACE_PRIVATE::TVariantIndexImpl<T, U>::Value;
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template <size_t I, CTVariant U>
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using TVariantAlternative = typename NAMESPACE_PRIVATE::TVariantAlternativeImpl<I, 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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constexpr TVariant() : TypeIndex(0xFF) { };
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constexpr TVariant(FInvalid) : TVariant() { };
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constexpr TVariant(const TVariant& InValue) requires (true && ... && CTriviallyCopyConstructible<Ts>) = default;
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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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constexpr TVariant(TVariant&& InValue) requires (true && ... && CTriviallyMoveConstructible<Ts>) = default;
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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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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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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 (NAMESPACE_PRIVATE::TVariantSelectedType<TRemoveReference<T>, Ts...>::Value
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&& !CTInPlaceType<TRemoveCVRef<T>> && !CTInPlaceIndex<TRemoveCVRef<T>>
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&& !CSameAs<TRemoveCVRef<T>, TVariant>)
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constexpr TVariant(T&& InValue) : TVariant(InPlaceType<typename NAMESPACE_PRIVATE::TVariantSelectedType<TRemoveReference<T>, Ts...>::Type>, Forward<T>(InValue))
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{ }
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constexpr ~TVariant() requires (true && ... && CTriviallyDestructible<Ts>) = default;
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constexpr ~TVariant() requires (!(true && ... && CTriviallyDestructible<Ts>))
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{
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Reset();
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}
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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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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 (NAMESPACE_PRIVATE::TVariantSelectedType<TRemoveReference<T>, Ts...>::Value)
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constexpr TVariant& operator=(T&& InValue)
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{
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using SelectedType = typename NAMESPACE_PRIVATE::TVariantSelectedType<TRemoveReference<T>, Ts...>::Type;
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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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template <size_t I, typename... ArgTypes> requires (I < sizeof...(Ts)
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&& CConstructibleFrom<TVariantAlternative<I, TVariant<Ts...>>, ArgTypes...>)
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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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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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constexpr const type_info& GetTypeInfo() const { return IsValid() ? *TypeInfos[GetIndex()] : typeid(void); }
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constexpr size_t GetIndex() const { return TypeIndex != 0xFF ? TypeIndex : INDEX_NONE; }
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constexpr bool IsValid() const { return TypeIndex != 0xFF; }
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constexpr explicit operator bool() const { return TypeIndex != 0xFF; }
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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() == TVariantIndex<T, TVariant<Ts...>> : false; }
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template <size_t I> requires (I < sizeof...(Ts)) 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)) 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)) 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)) 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> 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> 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> 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> 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)) 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)) constexpr decltype(auto) Get(const TVariantAlternative<I, TVariant<Ts...>>& DefaultValue) const& { return HoldsAlternative<I>() ? GetValue<I>() : DefaultValue; }
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template <typename T> constexpr decltype(auto) Get( T& DefaultValue) & { return HoldsAlternative<T>() ? GetValue<T>() : DefaultValue; }
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template <typename T> constexpr decltype(auto) Get(const T& DefaultValue) const& { return HoldsAlternative<T>() ? GetValue<T>() : DefaultValue; }
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template <typename F> requires (true && ... && CInvocable<F, Ts>)
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FORCEINLINE decltype(auto) Visit(F&& Func) &
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{
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checkf(IsValid(), TEXT("It is an error to call Visit() on an wrong TVariant. Please either check IsValid()."));
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using ReturnType = TCommonType<TInvokeResult<F, Ts>...>;
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using FInvokeImpl = ReturnType(*)(F&&, void*);
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static constexpr FInvokeImpl InvokeImpl[] = { [](F&& Func, void* This) -> ReturnType { return InvokeResult<ReturnType>(Forward<F>(Func), *reinterpret_cast<Ts*>(This)); }... };
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return InvokeImpl[GetIndex()](Forward<F>(Func), &Value);
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}
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template <typename F> requires (true && ... && CInvocable<F, Ts>)
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FORCEINLINE decltype(auto) Visit(F&& Func) &&
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{
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checkf(IsValid(), TEXT("It is an error to call Visit() on an wrong TVariant. Please either check IsValid()."));
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using ReturnType = TCommonType<TInvokeResult<F, Ts>...>;
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using FInvokeImpl = ReturnType(*)(F&&, void*);
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static constexpr FInvokeImpl InvokeImpl[] = { [](F&& Func, void* This) -> ReturnType { return InvokeResult<ReturnType>(Forward<F>(Func), MoveTemp(*reinterpret_cast<Ts*>(This))); }... };
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return InvokeImpl[GetIndex()](Forward<F>(Func), &Value);
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}
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template <typename F> requires (true && ... && CInvocable<F, Ts>)
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FORCEINLINE decltype(auto) Visit(F&& Func) const&
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{
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checkf(IsValid(), TEXT("It is an error to call Visit() on an wrong TVariant. Please either check IsValid()."));
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using ReturnType = TCommonType<TInvokeResult<F, Ts>...>;
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using FInvokeImpl = ReturnType(*)(F&&, const void*);
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static constexpr FInvokeImpl InvokeImpl[] = { [](F&& Func, const void* This) -> ReturnType { return InvokeResult<ReturnType>(Forward<F>(Func), *reinterpret_cast<const Ts*>(This)); }... };
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return InvokeImpl[GetIndex()](Forward<F>(Func), &Value);
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}
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template <typename F> requires (true && ... && CInvocable<F, Ts>)
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FORCEINLINE decltype(auto) Visit(F&& Func) const&&
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{
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checkf(IsValid(), TEXT("It is an error to call Visit() on an wrong TVariant. Please either check IsValid()."));
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using ReturnType = TCommonType<TInvokeResult<F, Ts>...>;
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using FInvokeImpl = ReturnType(*)(F&&, const void*);
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static constexpr FInvokeImpl InvokeImpl[] = { [](F&& Func, const void* This) -> ReturnType { return InvokeResult<ReturnType>(Forward<F>(Func), MoveTemp(*reinterpret_cast<const Ts*>(This))); }... };
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return InvokeImpl[GetIndex()](Forward<F>(Func), &Value);
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}
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template <typename R, typename F> requires (true && ... && CInvocableResult<R, F, Ts>)
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FORCEINLINE R Visit(F&& Func) & { return Visit(Forward<F>(Func)); }
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template <typename R, typename F> requires (true && ... && CInvocableResult<R, F, Ts>)
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FORCEINLINE R Visit(F&& Func) && { return MoveTemp(*this).Visit(Forward<F>(Func)); }
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template <typename R, typename F> requires (true && ... && CInvocableResult<R, F, Ts>)
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FORCEINLINE R Visit(F&& Func) const& { return Visit(Forward<F>(Func)); }
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template <typename R, typename F> requires (true && ... && CInvocableResult<R, F, Ts>)
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FORCEINLINE R Visit(F&& Func) const&& { return MoveTemp(*this).Visit(Forward<F>(Func)); }
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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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constexpr size_t GetTypeHash() const requires (true && ... && CHashable<Ts>)
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{
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if (!IsValid()) return 114514;
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using NAMESPACE_REDCRAFT::GetTypeHash;
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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(GetIndex()), HashImpl[GetIndex()](&Value));
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|
}
|
|
|
|
constexpr void Swap(TVariant& InValue) requires (true && ... && (CMoveConstructible<Ts> && CSwappable<Ts>))
|
|
{
|
|
if (!IsValid() && !InValue.IsValid()) return;
|
|
|
|
if (IsValid() && !InValue.IsValid())
|
|
{
|
|
InValue = MoveTemp(*this);
|
|
Reset();
|
|
return;
|
|
}
|
|
|
|
if (InValue.IsValid() && !IsValid())
|
|
{
|
|
*this = MoveTemp(InValue);
|
|
InValue.Reset();
|
|
return;
|
|
}
|
|
|
|
if (GetIndex() == InValue.GetIndex())
|
|
{
|
|
using NAMESPACE_REDCRAFT::Swap;
|
|
|
|
using FSwapImpl = void(*)(void*, void*);
|
|
constexpr FSwapImpl SwapImpl[] = { [](void* A, void* B) { Swap(*reinterpret_cast<Ts*>(A), *reinterpret_cast<Ts*>(B)); }... };
|
|
|
|
SwapImpl[GetIndex()](&Value, &InValue.Value);
|
|
|
|
return;
|
|
}
|
|
|
|
TVariant Temp = MoveTemp(*this);
|
|
*this = MoveTemp(InValue);
|
|
InValue = MoveTemp(Temp);
|
|
}
|
|
|
|
private:
|
|
|
|
static constexpr const type_info* TypeInfos[] = { &typeid(Ts)... };
|
|
|
|
using FCopyConstructImpl = void(*)(void*, const void*);
|
|
using FMoveConstructImpl = void(*)(void*, void*);
|
|
using FCopyAssignImpl = void(*)(void*, const void*);
|
|
using FMoveAssignImpl = void(*)(void*, void*);
|
|
using FDestroyImpl = void(*)(void* );
|
|
|
|
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()); }... };
|
|
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()); }... };
|
|
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()); }... };
|
|
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()); }... };
|
|
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()); }... };
|
|
|
|
TAlignedUnion<1, Ts...> Value;
|
|
uint8 TypeIndex;
|
|
|
|
friend constexpr bool operator==(const TVariant& LHS, const TVariant& RHS) requires (true && ... && CEqualityComparable<Ts>)
|
|
{
|
|
if (LHS.GetIndex() != RHS.GetIndex()) return false;
|
|
if (LHS.IsValid() == false) return true;
|
|
|
|
using FCompareImpl = bool(*)(const void*, const void*);
|
|
constexpr FCompareImpl CompareImpl[] = { [](const void* LHS, const void* RHS) -> bool { return *reinterpret_cast<const Ts*>(LHS) == *reinterpret_cast<const Ts*>(RHS); }... };
|
|
|
|
return CompareImpl[LHS.GetIndex()](&LHS.Value, &RHS.Value);
|
|
}
|
|
|
|
friend constexpr partial_ordering operator<=>(const TVariant& LHS, const TVariant& RHS) requires (true && ... && CSynthThreeWayComparable<Ts>)
|
|
{
|
|
if (LHS.GetIndex() != RHS.GetIndex()) return partial_ordering::unordered;
|
|
if (LHS.IsValid() == false) return partial_ordering::equivalent;
|
|
|
|
using FCompareImpl = partial_ordering(*)(const void*, const void*);
|
|
constexpr FCompareImpl CompareImpl[] = { [](const void* LHS, const void* RHS) -> partial_ordering { return SynthThreeWayCompare(*reinterpret_cast<const Ts*>(LHS), *reinterpret_cast<const Ts*>(RHS)); }...};
|
|
|
|
return CompareImpl[LHS.GetIndex()](&LHS.Value, &RHS.Value);
|
|
}
|
|
|
|
};
|
|
|
|
template <typename T, typename... Ts> requires (!CSameAs<T, TVariant<Ts...>> && CEqualityComparable<T>)
|
|
constexpr bool operator==(const TVariant<Ts...>& LHS, const T& RHS)
|
|
{
|
|
return LHS.template HoldsAlternative<T>() ? LHS.template GetValue<T>() == RHS : false;
|
|
}
|
|
|
|
template <typename... Ts>
|
|
constexpr bool operator==(const TVariant<Ts...>& LHS, FInvalid)
|
|
{
|
|
return !LHS.IsValid();
|
|
}
|
|
|
|
NAMESPACE_MODULE_END(Utility)
|
|
NAMESPACE_MODULE_END(Redcraft)
|
|
NAMESPACE_REDCRAFT_END
|