310 lines
9.7 KiB
C++
310 lines
9.7 KiB
C++
#pragma once
|
|
|
|
#include "CoreTypes.h"
|
|
#include "Templates/Utility.h"
|
|
#include "Templates/TypeHash.h"
|
|
#include "Concepts/Comparable.h"
|
|
#include "TypeTraits/TypeTraits.h"
|
|
#include "Miscellaneous/Compare.h"
|
|
#include "Miscellaneous/AssertionMacros.h"
|
|
|
|
NAMESPACE_REDCRAFT_BEGIN
|
|
NAMESPACE_MODULE_BEGIN(Redcraft)
|
|
NAMESPACE_MODULE_BEGIN(Utility)
|
|
|
|
template <typename OptionalType> requires CDestructible<OptionalType>
|
|
struct TOptional
|
|
{
|
|
private:
|
|
|
|
template <typename T>
|
|
struct TAllowUnwrapping : TBoolConstant<!(
|
|
CConstructible<OptionalType, TOptional<T>& >
|
|
|| CConstructible<OptionalType, const TOptional<T>& >
|
|
|| CConstructible<OptionalType, TOptional<T>&&>
|
|
|| CConstructible<OptionalType, const TOptional<T>&&>
|
|
|| CConvertibleTo< TOptional<T>&, OptionalType>
|
|
|| CConvertibleTo<const TOptional<T>&, OptionalType>
|
|
|| CConvertibleTo< TOptional<T>&&, OptionalType>
|
|
|| CConvertibleTo<const TOptional<T>&&, OptionalType>
|
|
|| CAssignable<OptionalType&, TOptional<T>& >
|
|
|| CAssignable<OptionalType&, const TOptional<T>& >
|
|
|| CAssignable<OptionalType&, TOptional<T>&&>
|
|
|| CAssignable<OptionalType&, const TOptional<T>&&>
|
|
)> { };
|
|
|
|
public:
|
|
|
|
using ValueType = OptionalType;
|
|
|
|
constexpr TOptional() : bIsValid(false) { }
|
|
|
|
constexpr TOptional(FInvalid) : TOptional() { }
|
|
|
|
template <typename... Types> requires CConstructible<OptionalType, Types...>
|
|
constexpr explicit TOptional(FInPlace, Types&&... Args)
|
|
: bIsValid(true)
|
|
{
|
|
new(&Value) OptionalType(Forward<Types>(Args)...);
|
|
}
|
|
|
|
template <typename T = OptionalType> requires CConstructible<OptionalType, T&&>
|
|
&& (!CSameAs<typename TRemoveCVRef<T>::Type, FInPlace>) && (!CSameAs<typename TRemoveCVRef<T>::Type, TOptional>)
|
|
constexpr explicit (!CConvertibleTo<T&&, OptionalType>) TOptional(T&& InValue)
|
|
: TOptional(InPlace, Forward<T>(InValue))
|
|
{ }
|
|
|
|
constexpr TOptional(const TOptional& InValue) requires CCopyConstructible<OptionalType>
|
|
: bIsValid(InValue.IsValid())
|
|
{
|
|
if (InValue.IsValid()) new(&Value) OptionalType(InValue.GetValue());
|
|
}
|
|
|
|
constexpr TOptional(TOptional&& InValue) requires CMoveConstructible<OptionalType>
|
|
: bIsValid(InValue.IsValid())
|
|
{
|
|
if (InValue.IsValid()) new(&Value) OptionalType(MoveTemp(InValue.GetValue()));
|
|
}
|
|
|
|
template <typename T = OptionalType> requires CConstructible<OptionalType, const T&> && TAllowUnwrapping<T>::Value
|
|
constexpr explicit (!CConvertibleTo<const T&, OptionalType>) TOptional(const TOptional<T>& InValue)
|
|
: bIsValid(InValue.IsValid())
|
|
{
|
|
if (InValue.IsValid()) new(&Value) OptionalType(InValue.GetValue());
|
|
}
|
|
|
|
template <typename T = OptionalType> requires CConstructible<OptionalType, T&&> && TAllowUnwrapping<T>::Value
|
|
constexpr explicit (!CConvertibleTo<T&&, OptionalType>) TOptional(TOptional<T>&& InValue)
|
|
: bIsValid(InValue.IsValid())
|
|
{
|
|
if (InValue.IsValid()) new(&Value) OptionalType(MoveTemp(InValue.GetValue()));
|
|
}
|
|
|
|
constexpr ~TOptional()
|
|
{
|
|
if constexpr (!CTriviallyDestructible<OptionalType>) Reset();
|
|
}
|
|
|
|
constexpr TOptional& operator=(const TOptional& InValue) requires CCopyConstructible<OptionalType> && CCopyAssignable<OptionalType>
|
|
{
|
|
if (&InValue == this) return *this;
|
|
|
|
if (!InValue.IsValid())
|
|
{
|
|
Reset();
|
|
return *this;
|
|
}
|
|
|
|
if (IsValid()) GetValue() = InValue.GetValue();
|
|
else
|
|
{
|
|
new(&Value) OptionalType(InValue.GetValue());
|
|
bIsValid = true;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
constexpr TOptional& operator=(TOptional&& InValue) requires CMoveConstructible<OptionalType> && CMoveAssignable<OptionalType>
|
|
{
|
|
if (&InValue == this) return *this;
|
|
|
|
if (!InValue.IsValid())
|
|
{
|
|
Reset();
|
|
return *this;
|
|
}
|
|
|
|
if (IsValid()) GetValue() = MoveTemp(InValue.GetValue());
|
|
else
|
|
{
|
|
new(&Value) OptionalType(MoveTemp(InValue.GetValue()));
|
|
bIsValid = true;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template <typename T = OptionalType> requires CConstructible<OptionalType, const T&> && CAssignable<OptionalType&, const T&> && TAllowUnwrapping<T>::Value
|
|
constexpr TOptional& operator=(const TOptional<T>& InValue)
|
|
{
|
|
if (!InValue.IsValid())
|
|
{
|
|
Reset();
|
|
return *this;
|
|
}
|
|
|
|
if (IsValid()) GetValue() = InValue.GetValue();
|
|
else
|
|
{
|
|
new(&Value) OptionalType(InValue.GetValue());
|
|
bIsValid = true;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template <typename T = OptionalType> requires CConstructible<OptionalType, T&&> && CAssignable<OptionalType&, T&&> && TAllowUnwrapping<T>::Value
|
|
constexpr TOptional& operator=(TOptional<T>&& InValue)
|
|
{
|
|
if (!InValue.IsValid())
|
|
{
|
|
Reset();
|
|
return *this;
|
|
}
|
|
|
|
if (IsValid()) GetValue() = MoveTemp(InValue.GetValue());
|
|
else
|
|
{
|
|
new(&Value) OptionalType(MoveTemp(InValue.GetValue()));
|
|
bIsValid = true;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template <typename T = OptionalType> requires CConstructible<OptionalType, T&&> && CAssignable<OptionalType&, T&&>
|
|
constexpr TOptional& operator=(T&& InValue)
|
|
{
|
|
if (IsValid()) GetValue() = Forward<T>(InValue);
|
|
else
|
|
{
|
|
new(&Value) OptionalType(Forward<T>(InValue));
|
|
bIsValid = true;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template <typename... ArgTypes> requires CConstructible<OptionalType, ArgTypes...>
|
|
constexpr OptionalType& Emplace(ArgTypes&&... Args)
|
|
{
|
|
Reset();
|
|
|
|
OptionalType* Result = new(&Value) OptionalType(Forward<ArgTypes>(Args)...);
|
|
bIsValid = true;
|
|
|
|
return *Result;
|
|
}
|
|
|
|
constexpr bool IsValid() const { return bIsValid; }
|
|
constexpr explicit operator bool() const { return bIsValid; }
|
|
|
|
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 *reinterpret_cast< OptionalType*>(&Value); }
|
|
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 MoveTemp(*reinterpret_cast< OptionalType*>(&Value)); }
|
|
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 *reinterpret_cast<const OptionalType*>(&Value); }
|
|
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 MoveTemp(*reinterpret_cast<const OptionalType*>(&Value)); }
|
|
|
|
constexpr const OptionalType* operator->() const { return &GetValue(); }
|
|
constexpr OptionalType* operator->() { return &GetValue(); }
|
|
|
|
constexpr OptionalType& operator*() & { return GetValue(); }
|
|
constexpr OptionalType&& operator*() && { return GetValue(); }
|
|
constexpr const OptionalType& operator*() const& { return GetValue(); }
|
|
constexpr const OptionalType&& operator*() const&& { return GetValue(); }
|
|
|
|
constexpr OptionalType& Get( OptionalType& DefaultValue) & { return IsValid() ? GetValue() : DefaultValue; }
|
|
constexpr const OptionalType& Get(const OptionalType& DefaultValue) const& { return IsValid() ? GetValue() : DefaultValue; }
|
|
|
|
constexpr void Reset()
|
|
{
|
|
if (bIsValid)
|
|
{
|
|
bIsValid = false;
|
|
|
|
typedef OptionalType DestructOptionalType;
|
|
((OptionalType*)&Value)->DestructOptionalType::~DestructOptionalType();
|
|
}
|
|
}
|
|
|
|
constexpr size_t GetTypeHash() const requires CHashable<OptionalType>
|
|
{
|
|
if (!IsValid()) return 2824517378;
|
|
return NAMESPACE_REDCRAFT::GetTypeHash(GetValue());
|
|
}
|
|
|
|
template <typename T> requires CMoveConstructible<OptionalType> && TIsSwappable<OptionalType>::Value
|
|
constexpr void Swap(TOptional& InValue)
|
|
{
|
|
if (!IsValid() && !InValue.IsValid()) return;
|
|
|
|
if (IsValid() && !InValue.IsValid())
|
|
{
|
|
InValue = MoveTemp(*this);
|
|
Reset();
|
|
return;
|
|
}
|
|
|
|
if (InValue.IsValid() && !IsValid())
|
|
{
|
|
*this = MoveTemp(InValue);
|
|
InValue.Reset();
|
|
return;
|
|
}
|
|
|
|
NAMESPACE_REDCRAFT::Swap(GetValue(), InValue.GetValue());
|
|
}
|
|
|
|
private:
|
|
|
|
TAlignedStorage<sizeof(OptionalType), alignof(OptionalType)>::Type Value;
|
|
bool bIsValid;
|
|
|
|
};
|
|
|
|
template <typename T>
|
|
TOptional(T) -> TOptional<T>;
|
|
|
|
template <typename T, typename U> requires CWeaklyEqualityComparableWith<T, U>
|
|
constexpr bool operator==(const TOptional<T>& LHS, const TOptional<U>& RHS)
|
|
{
|
|
if (LHS.IsValid() != RHS.IsValid()) return false;
|
|
if (LHS.IsValid() == false) return true;
|
|
return *LHS == *RHS;
|
|
}
|
|
|
|
template <typename T, typename U> requires CSynthThreeWayComparableWith<T, U>
|
|
constexpr partial_ordering operator<=>(const TOptional<T>& LHS, const TOptional<U>& RHS)
|
|
{
|
|
if (LHS.IsValid() != RHS.IsValid()) return partial_ordering::unordered;
|
|
if (LHS.IsValid() == false) return partial_ordering::equivalent;
|
|
return SynthThreeWayCompare(*LHS, *RHS);
|
|
}
|
|
|
|
template <typename T, typename U> requires CWeaklyEqualityComparableWith<T, U>
|
|
constexpr bool operator==(const TOptional<T>& LHS, const U& RHS)
|
|
{
|
|
return LHS.IsValid() ? *LHS == RHS : false;
|
|
}
|
|
|
|
template <typename T>
|
|
constexpr bool operator==(const TOptional<T>& LHS, FInvalid)
|
|
{
|
|
return !LHS.IsValid();
|
|
}
|
|
|
|
template <typename T> requires CDestructible<T>
|
|
constexpr TOptional<typename TDecay<T>::Type> MakeOptional(FInvalid)
|
|
{
|
|
return TOptional<typename TDecay<T>::Type>(Invalid);
|
|
}
|
|
|
|
template <typename T> requires CDestructible<T> && CConstructible<T, T&&>
|
|
constexpr TOptional<T> MakeOptional(T&& InValue)
|
|
{
|
|
return TOptional<T>(Forward<T>(InValue));
|
|
}
|
|
|
|
template <typename T, typename... Types> requires CDestructible<T> && CConstructible<T, Types...>
|
|
constexpr TOptional<T> MakeOptional(Types&&... Args)
|
|
{
|
|
return TOptional<T>(InPlace, Forward<T>(Args)...);
|
|
}
|
|
|
|
template <typename T> struct TIsTOptional : FFalse { };
|
|
template <typename T> struct TIsTOptional<TOptional<T>> : FTrue { };
|
|
|
|
NAMESPACE_MODULE_END(Utility)
|
|
NAMESPACE_MODULE_END(Redcraft)
|
|
NAMESPACE_REDCRAFT_END
|