Redcraft/Redcraft.Utility/Source/Public/Templates/ReferenceWrapper.h

249 lines
8.9 KiB
C
Raw Normal View History

#pragma once
#include "CoreTypes.h"
#include "Templates/Invoke.h"
#include "Templates/Utility.h"
#include "Templates/Optional.h"
#include "TypeTraits/TypeTraits.h"
NAMESPACE_REDCRAFT_BEGIN
NAMESPACE_MODULE_BEGIN(Redcraft)
NAMESPACE_MODULE_BEGIN(Utility)
template <typename ReferencedType> requires (CObject<ReferencedType> || CFunction<ReferencedType>)
class TReferenceWrapper
{
public:
using Type = ReferencedType;
template <typename T = ReferencedType> requires (CConvertibleTo<T, ReferencedType&>)
FORCEINLINE constexpr TReferenceWrapper(T&& Object)
{
ReferencedType& Reference = Forward<T>(Object);
Pointer = AddressOf(Reference);
}
FORCEINLINE constexpr TReferenceWrapper(const TReferenceWrapper&) = default;
template <typename T = ReferencedType> requires (CConvertibleTo<T&, ReferencedType&>)
FORCEINLINE constexpr TReferenceWrapper(const TReferenceWrapper<T>& InValue)
: Pointer(InValue.Pointer)
{ }
FORCEINLINE constexpr TReferenceWrapper& operator=(const TReferenceWrapper&) = default;
template <typename T = ReferencedType> requires (CConvertibleTo<T&, ReferencedType&>)
FORCEINLINE constexpr TReferenceWrapper& operator=(const TReferenceWrapper<T>& InValue)
{
Pointer = InValue.Pointer;
return *this;
}
FORCEINLINE constexpr operator ReferencedType&() const { return *Pointer; }
FORCEINLINE constexpr ReferencedType& Get() const { return *Pointer; }
template <typename... Ts>
FORCEINLINE constexpr TInvokeResult<ReferencedType&, Ts...> operator()(Ts&&... Args) const
{
return Invoke(Get(), Forward<Ts>(Args)...);
}
FORCEINLINE constexpr size_t GetTypeHash() const requires (CHashable<ReferencedType>)
{
return NAMESPACE_REDCRAFT::GetTypeHash(Get());
}
FORCEINLINE constexpr void Swap(TReferenceWrapper& InValue)
{
ReferencedType* Temp = Pointer;
Pointer = InValue.Pointer;
InValue.Pointer = Temp;
}
private:
ReferencedType* Pointer;
template <typename T> requires (CObject<T> || CFunction<T>) friend class TReferenceWrapper;
// Optimize TOptional with these hacking
FORCEINLINE constexpr TReferenceWrapper(FInvalid) : Pointer(nullptr) { };
template <typename T> requires (CDestructible<T>) friend class TOptional;
};
template <typename T>
TReferenceWrapper(T&) -> TReferenceWrapper<T>;
template <typename T>
void Ref(const T&&) = delete;
template <typename T>
FORCEINLINE constexpr TReferenceWrapper<T> Ref(T& InValue)
{
return TReferenceWrapper<T>(InValue);
}
template <typename T>
FORCEINLINE constexpr TReferenceWrapper<T> Ref(TReferenceWrapper<T> InValue)
{
return Ref(InValue.Get());
}
template <typename T>
FORCEINLINE constexpr TReferenceWrapper<const T> Ref(const T& InValue)
{
return TReferenceWrapper<const T>(InValue);
}
template <typename T>
FORCEINLINE constexpr TReferenceWrapper<const T> Ref(TReferenceWrapper<T> InValue)
{
return Ref(InValue.Get());
}
NAMESPACE_PRIVATE_BEGIN
template <typename T> struct TIsTReferenceWrapperImpl : FFalse { };
template <typename T> struct TIsTReferenceWrapperImpl<TReferenceWrapper<T>> : FTrue { };
template <typename T> struct TUnwrapReferenceImpl { using Type = T; };
template <typename T> struct TUnwrapReferenceImpl<TReferenceWrapper<T>> { using Type = T&; };
template <typename T> struct TUnwrapRefDecayImpl { using Type = typename TUnwrapReferenceImpl<TDecay<T>>::Type; };
NAMESPACE_PRIVATE_END
template <typename T>
concept CTReferenceWrapper = NAMESPACE_PRIVATE::TIsTReferenceWrapperImpl<TRemoveCV<T>>::Value;
template <typename T>
using TUnwrapReference = typename NAMESPACE_PRIVATE::TUnwrapReferenceImpl<T>::Type;
template <typename T>
using TUnwrapRefDecay = typename NAMESPACE_PRIVATE::TUnwrapRefDecayImpl<T>::Type;
template <typename ReferencedType>
class TOptional<TReferenceWrapper<ReferencedType>>
{
private:
using OptionalType = TReferenceWrapper<ReferencedType>;
template <typename T>
struct TAllowUnwrapping : TBoolConstant < !(
CConstructibleFrom<OptionalType, TOptional<T>& >
|| CConstructibleFrom<OptionalType, const TOptional<T>& >
|| CConstructibleFrom<OptionalType, TOptional<T>&&>
|| CConstructibleFrom<OptionalType, const TOptional<T>&&>
|| CConvertibleTo< TOptional<T>&, OptionalType>
|| CConvertibleTo<const TOptional<T>&, OptionalType>
|| CConvertibleTo< TOptional<T>&&, OptionalType>
|| CConvertibleTo<const TOptional<T>&&, OptionalType>
|| CAssignableFrom<OptionalType&, TOptional<T>& >
|| CAssignableFrom<OptionalType&, const TOptional<T>& >
|| CAssignableFrom<OptionalType&, TOptional<T>&&>
|| CAssignableFrom<OptionalType&, const TOptional<T>&&>
)> { };
public:
using ValueType = OptionalType;
FORCEINLINE constexpr TOptional() : Reference(Invalid) { }
FORCEINLINE constexpr TOptional(FInvalid) : TOptional() { }
template <typename... Ts> requires (CConstructibleFrom<OptionalType, Ts...>)
FORCEINLINE constexpr explicit TOptional(FInPlace, Ts&&... Args)
: Reference(Forward<Ts>(Args)...)
{ }
template <typename T = OptionalType> requires (CConstructibleFrom<OptionalType, T&&>
&& !CSameAs<TRemoveCVRef<T>, FInPlace> && !CBaseOf<TOptional, TRemoveCVRef<T>>)
FORCEINLINE constexpr explicit (!CConvertibleTo<T&&, OptionalType>) TOptional(T&& InValue)
: TOptional(InPlace, Forward<T>(InValue))
{ }
FORCEINLINE TOptional(const TOptional& InValue) = default;
FORCEINLINE TOptional(TOptional&& InValue) = default;
template <typename T = OptionalType> requires (CConstructibleFrom<OptionalType, const T&> && TAllowUnwrapping<T>::Value)
FORCEINLINE constexpr explicit (!CConvertibleTo<const T&, OptionalType>) TOptional(const TOptional<T>& InValue)
: Reference(InValue.Reference)
{ }
FORCEINLINE ~TOptional() = default;
FORCEINLINE TOptional& operator=(const TOptional& InValue) = default;
FORCEINLINE TOptional& operator=(TOptional&& InValue) = default;
template <typename T = OptionalType> requires (CConstructibleFrom<OptionalType, const T&>
&& CAssignableFrom<OptionalType&, const T&> && TAllowUnwrapping<T>::Value)
FORCEINLINE constexpr TOptional& operator=(const TOptional<T>& InValue)
{
Reference = InValue.Reference;
return *this;
}
template <typename T = OptionalType> requires (CConstructibleFrom<OptionalType, T&&> && CAssignableFrom<OptionalType&, T&&>)
FORCEINLINE constexpr TOptional& operator=(T&& InValue)
{
Reference = InValue;
return *this;
}
template <typename... ArgTypes> requires (CConstructibleFrom<OptionalType, ArgTypes...>)
FORCEINLINE constexpr OptionalType& Emplace(ArgTypes&&... Args)
{
Reference = TReferenceWrapper<ReferencedType>(Forward<ArgTypes>(Args)...);
return Reference;
}
FORCEINLINE constexpr bool IsValid() const { return Reference.Pointer != nullptr; }
FORCEINLINE constexpr explicit operator bool() const { return Reference.Pointer != nullptr; }
FORCEINLINE constexpr OptionalType& GetValue() & { checkf(IsValid(), TEXT("It is an error to call GetValue() on an unset TOptional. Please either check IsValid() or use Get(DefaultValue) instead.")); return Reference; }
FORCEINLINE constexpr OptionalType&& GetValue() && { checkf(IsValid(), TEXT("It is an error to call GetValue() on an unset TOptional. Please either check IsValid() or use Get(DefaultValue) instead.")); return Reference; }
FORCEINLINE constexpr const OptionalType& GetValue() const& { checkf(IsValid(), TEXT("It is an error to call GetValue() on an unset TOptional. Please either check IsValid() or use Get(DefaultValue) instead.")); return Reference; }
FORCEINLINE constexpr const OptionalType&& GetValue() const&& { checkf(IsValid(), TEXT("It is an error to call GetValue() on an unset TOptional. Please either check IsValid() or use Get(DefaultValue) instead.")); return Reference; }
FORCEINLINE constexpr const OptionalType* operator->() const { return &GetValue(); }
FORCEINLINE constexpr OptionalType* operator->() { return &GetValue(); }
FORCEINLINE constexpr OptionalType& operator*() & { return GetValue(); }
FORCEINLINE constexpr OptionalType&& operator*() && { return GetValue(); }
FORCEINLINE constexpr const OptionalType& operator*() const& { return GetValue(); }
FORCEINLINE constexpr const OptionalType&& operator*() const&& { return GetValue(); }
FORCEINLINE constexpr OptionalType& Get( OptionalType& DefaultValue) & { return IsValid() ? GetValue() : DefaultValue; }
FORCEINLINE constexpr const OptionalType& Get(const OptionalType& DefaultValue) const& { return IsValid() ? GetValue() : DefaultValue; }
FORCEINLINE constexpr void Reset()
{
Reference = Invalid;
}
FORCEINLINE constexpr size_t GetTypeHash() const requires (CHashable<ReferencedType>)
{
if (!IsValid()) return 2824517378;
return Reference.GetTypeHash();
}
FORCEINLINE constexpr void Swap(TOptional& InValue)
{
Reference.Swap(InValue.Reference);
}
private:
TReferenceWrapper<ReferencedType> Reference;
template <typename T> requires (CDestructible<T>) friend class TOptional;
};
NAMESPACE_MODULE_END(Utility)
NAMESPACE_MODULE_END(Redcraft)
NAMESPACE_REDCRAFT_END