Redcraft/Redcraft.Utility/Source/Public/Containers/Iterator.h

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#pragma once
#include "CoreTypes.h"
#include "Templates/Invoke.h"
#include "Templates/Utility.h"
#include "Templates/Noncopyable.h"
#include "TypeTraits/TypeTraits.h"
#include "Miscellaneous/Compare.h"
#include "Miscellaneous/AssertionMacros.h"
NAMESPACE_REDCRAFT_BEGIN
NAMESPACE_MODULE_BEGIN(Redcraft)
NAMESPACE_MODULE_BEGIN(Utility)
NAMESPACE_PRIVATE_BEGIN
template <typename T> using WithReference = T&;
template <typename I>
struct TIteratorElementType
{
using Type = typename I::ElementType;
};
template <typename T>
struct TIteratorElementType<T*>
{
using Type = T;
};
NAMESPACE_PRIVATE_END
template <typename T>
concept CReferenceable = requires { typename NAMESPACE_PRIVATE::WithReference<T>; };
template <typename T>
concept CDereferenceable = requires(T& A) { { *A } -> CReferenceable; };
template <typename I>
using TIteratorElementType = typename NAMESPACE_PRIVATE::TIteratorElementType<TRemoveCVRef<I>>::Type;
template <CReferenceable I>
using TIteratorReferenceType = decltype(*DeclVal<I&>());
template <CReferenceable I> requires (requires(I& Iter) { { MoveTemp(*Iter) } -> CReferenceable; })
using TIteratorRValueReferenceType = decltype(MoveTemp(*DeclVal<I&>()));
template <typename I>
concept CIndirectlyReadable =
requires(const TRemoveCVRef<I> Iter)
{
typename TIteratorElementType<I>;
typename TIteratorReferenceType<I>;
typename TIteratorRValueReferenceType<I>;
{ *Iter } -> CSameAs<TIteratorReferenceType<I>>;
{ MoveTemp(*Iter) } -> CSameAs<TIteratorRValueReferenceType<I>>;
}
&& CCommonReference<TIteratorReferenceType<I>&&, TIteratorElementType<I>&>
&& CCommonReference<TIteratorReferenceType<I>&&, TIteratorRValueReferenceType<I>&&>
&& CCommonReference<TIteratorRValueReferenceType<I>&&, const TIteratorElementType<I>&>;
template <typename I, typename T>
concept CIndirectlyWritable =
requires(I&& Iter, T&& A)
{
*Iter = Forward<T>(A);
*Forward<I>(Iter) = Forward<T>(A);
const_cast<const TIteratorElementType<I>&&>(*Iter) = Forward<T>(A);
const_cast<const TIteratorElementType<I>&&>(*Forward<I>(Iter)) = Forward<T>(A);
};
template <typename I>
concept CWeaklyIncrementable = CMovable<I>
&& requires(I Iter) { { ++Iter } -> CSameAs<I&>; Iter++; };
template <typename I>
concept CIncrementable = CRegular<I> && CWeaklyIncrementable<I>
&& requires(I Iter) { { Iter++ } -> CSameAs<I>; };
template <typename I>
concept CInputOrOutputIterator = CWeaklyIncrementable<I>
&& requires(I Iter) { { *Iter } -> CReferenceable; };
template <typename S, typename I>
concept CSentinelFor = CSemiregular<S> && CInputOrOutputIterator<I> && CWeaklyEqualityComparable<S, I>;
template <typename S, typename I>
inline constexpr bool bDisableSizedSentinelFor = false;
template <typename S, typename I>
concept CSizedSentinelFor = CSentinelFor<S, I> && CPartiallyOrdered<S, I> && !bDisableSizedSentinelFor<TRemoveCV<S>, TRemoveCV<I>>
&& requires(const I& Iter, const S& Sentinel) { Sentinel - Iter; Iter - Sentinel; };
template <typename I>
concept CInputIterator = CInputOrOutputIterator<I> && CIndirectlyReadable<I>;
template <typename I, typename T>
concept COutputIterator = CInputOrOutputIterator<I> && CIndirectlyWritable<I, T>
&& requires(I Iter, T&& A) { *Iter++ = Forward<T>(A); };
template <typename I>
concept CForwardIterator = CInputIterator<I> && CIncrementable<I> && CSentinelFor<I, I>;
template <typename I>
concept CBidirectionalIterator = CForwardIterator<I>
&& requires(I Iter) {
{ --Iter } -> CSameAs<I&>;
{ Iter-- } -> CSameAs<I >;
};
template <typename I>
concept CRandomAccessIterator = CBidirectionalIterator<I> && CTotallyOrdered<I> && CSizedSentinelFor<I, I>
&& requires(I Iter, const I Jter, const ptrdiff N) {
{ Iter += N } -> CSameAs<I&>;
{ Jter + N } -> CSameAs<I >;
{ N + Jter } -> CSameAs<I >;
{ Iter -= N } -> CSameAs<I&>;
{ Jter - N } -> CSameAs<I >;
{ Jter[N] } -> CSameAs<TIteratorReferenceType<I>>;
};
template <typename I>
concept CContiguousIterator = CRandomAccessIterator<I> && CLValueReference<TIteratorReferenceType<I>>
&& CSameAs<TIteratorElementType<I>, TRemoveReference<TIteratorReferenceType<I>>>
&& requires(I& Iter)
{
static_cast<TAddPointer<TIteratorReferenceType<I>>>(Iter);
{ AddressOf(*Iter) } -> CSameAs<TAddPointer<TIteratorReferenceType<I>>>;
};
static_assert(CContiguousIterator<int32*>);
/** A iterator adaptor for reverse-order traversal. */
template <CBidirectionalIterator I>
class TReverseIterator final
{
public:
using IteratorType = I;
using ElementType = TIteratorElementType<I>;
FORCEINLINE constexpr TReverseIterator() = default;
FORCEINLINE constexpr TReverseIterator(const TReverseIterator&) = default;
FORCEINLINE constexpr TReverseIterator(TReverseIterator&&) = default;
FORCEINLINE constexpr TReverseIterator& operator=(const TReverseIterator&) = default;
FORCEINLINE constexpr TReverseIterator& operator=(TReverseIterator&&) = default;
FORCEINLINE constexpr explicit TReverseIterator(IteratorType InValue) : Current(InValue) { }
template <CBidirectionalIterator J> requires (!CSameAs<IteratorType, J> && CConvertibleTo<const J&, IteratorType>)
FORCEINLINE constexpr TReverseIterator(const TReverseIterator<J>& InValue) : Current(InValue.GetBase()) { }
template <CBidirectionalIterator J> requires (!CSameAs<IteratorType, J> && CConvertibleTo<const J&, IteratorType> && CAssignableFrom<IteratorType&, const J&>)
FORCEINLINE constexpr TReverseIterator& operator=(const TReverseIterator<J>& InValue) { Current = InValue.GetBase(); return *this; }
template <CBidirectionalIterator J> requires (CSentinelFor<J, IteratorType>)
NODISCARD friend FORCEINLINE constexpr bool operator==(const TReverseIterator& LHS, const TReverseIterator<J>& RHS) { return LHS.GetBase() == RHS.GetBase(); }
template <CBidirectionalIterator J> requires (CSizedSentinelFor<J, IteratorType>)
NODISCARD friend FORCEINLINE constexpr TCompareThreeWayResult<J, IteratorType> operator<=>(const TReverseIterator& LHS, const TReverseIterator<J>& RHS) { return RHS.GetBase() <=> LHS.GetBase(); }
NODISCARD FORCEINLINE constexpr ElementType& operator*() const { IteratorType Temp = GetBase(); return *--Temp; }
NODISCARD FORCEINLINE constexpr ElementType* operator->() const { return AddressOf(operator*()); }
NODISCARD FORCEINLINE constexpr ElementType& operator[](ptrdiff Index) const requires (CRandomAccessIterator<IteratorType>) { return GetBase()[-Index - 1]; }
FORCEINLINE constexpr TReverseIterator& operator++() { --Current; return *this; }
FORCEINLINE constexpr TReverseIterator& operator--() { ++Current; return *this; }
FORCEINLINE constexpr TReverseIterator operator++(int) { TReverseIterator Temp = *this; --Current; return Temp; }
FORCEINLINE constexpr TReverseIterator operator--(int) { TReverseIterator Temp = *this; ++Current; return Temp; }
FORCEINLINE constexpr TReverseIterator& operator+=(ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { Current -= Offset; return *this; }
FORCEINLINE constexpr TReverseIterator& operator-=(ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { Current += Offset; return *this; }
NODISCARD friend FORCEINLINE constexpr TReverseIterator operator+(TReverseIterator Iter, ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { TReverseIterator Temp = Iter; Temp -= Offset; return Temp; }
NODISCARD friend FORCEINLINE constexpr TReverseIterator operator+(ptrdiff Offset, TReverseIterator Iter) requires (CRandomAccessIterator<IteratorType>) { TReverseIterator Temp = Iter; Temp -= Offset; return Temp; }
NODISCARD FORCEINLINE constexpr TReverseIterator operator-(ptrdiff Offset) const requires (CRandomAccessIterator<IteratorType>) { TReverseIterator Temp = *this; Temp += Offset; return Temp; }
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(const TReverseIterator& LHS, const TReverseIterator& RHS) { return RHS.GetBase() - LHS.GetBase(); }
NODISCARD FORCEINLINE constexpr const IteratorType& GetBase() const& { return Current; }
NODISCARD FORCEINLINE constexpr IteratorType GetBase() && { return Current; }
private:
IteratorType Current;
};
static_assert(CRandomAccessIterator<TReverseIterator<int32*>>);
template <typename I>
TReverseIterator(I) -> TReverseIterator<I>;
template <typename I, typename J> requires (!CSizedSentinelFor<I, J>)
inline constexpr bool bDisableSizedSentinelFor<TReverseIterator<I>, TReverseIterator<J>> = true;
/** An iterator adaptor which dereferences to an rvalue reference. */
template <CInputIterator I>
class TMoveIterator final
{
public:
using IteratorType = I;
using ElementType = TIteratorElementType<I>;
FORCEINLINE constexpr TMoveIterator() = default;
FORCEINLINE constexpr TMoveIterator(const TMoveIterator&) = default;
FORCEINLINE constexpr TMoveIterator(TMoveIterator&&) = default;
FORCEINLINE constexpr TMoveIterator& operator=(const TMoveIterator&) = default;
FORCEINLINE constexpr TMoveIterator& operator=(TMoveIterator&&) = default;
FORCEINLINE constexpr explicit TMoveIterator(IteratorType InValue) : Current(InValue) { }
template <CInputIterator J> requires (!CSameAs<IteratorType, J> && CConvertibleTo<const J&, IteratorType>)
FORCEINLINE constexpr TMoveIterator(const TMoveIterator<J>& InValue) : Current(InValue.GetBase()) { }
template <CInputIterator J> requires (!CSameAs<IteratorType, J> && CConvertibleTo<const J&, IteratorType> && CAssignableFrom<IteratorType&, const J&>)
FORCEINLINE constexpr TMoveIterator& operator=(const TMoveIterator<J>& InValue) { Current = InValue.GetBase(); return *this; }
template <CInputIterator J> requires (CSentinelFor<J, IteratorType>)
NODISCARD friend FORCEINLINE constexpr bool operator==(const TMoveIterator& LHS, const TMoveIterator<J>& RHS) { return LHS.GetBase() == RHS.GetBase(); }
template <CInputIterator J> requires (CSizedSentinelFor<J, IteratorType>)
NODISCARD friend FORCEINLINE constexpr TCompareThreeWayResult<J, IteratorType> operator<=>(const TMoveIterator& LHS, const TMoveIterator<J>& RHS) { return LHS.GetBase() <=> RHS.GetBase(); }
NODISCARD FORCEINLINE constexpr ElementType&& operator*() const { return MoveTemp(*GetBase()); }
NODISCARD FORCEINLINE constexpr ElementType* operator->() const = delete;
NODISCARD FORCEINLINE constexpr ElementType&& operator[](ptrdiff Index) const requires (CRandomAccessIterator<IteratorType>) { return MoveTemp(GetBase()[Index]); }
FORCEINLINE constexpr TMoveIterator& operator++() { ++Current; return *this; }
FORCEINLINE constexpr TMoveIterator& operator--() requires (CBidirectionalIterator<IteratorType>) { --Current; return *this; }
FORCEINLINE constexpr void operator++(int) { Current++; }
FORCEINLINE constexpr TMoveIterator operator++(int) requires (CForwardIterator<IteratorType>) { return TMoveIterator(Current++); }
FORCEINLINE constexpr TMoveIterator operator--(int) requires (CBidirectionalIterator<IteratorType>) { return TMoveIterator(Current--); }
FORCEINLINE constexpr TMoveIterator& operator+=(ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { Current += Offset; return *this; }
FORCEINLINE constexpr TMoveIterator& operator-=(ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { Current -= Offset; return *this; }
NODISCARD friend FORCEINLINE constexpr TMoveIterator operator+(TMoveIterator Iter, ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { TMoveIterator Temp = Iter; Temp += Offset; return Temp; }
NODISCARD friend FORCEINLINE constexpr TMoveIterator operator+(ptrdiff Offset, TMoveIterator Iter) requires (CRandomAccessIterator<IteratorType>) { TMoveIterator Temp = Iter; Temp += Offset; return Temp; }
NODISCARD FORCEINLINE constexpr TMoveIterator operator-(ptrdiff Offset) const requires (CRandomAccessIterator<IteratorType>) { TMoveIterator Temp = *this; Temp -= Offset; return Temp; }
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(const TMoveIterator& LHS, const TMoveIterator& RHS) { return LHS.GetBase() - RHS.GetBase(); }
NODISCARD FORCEINLINE constexpr const IteratorType& GetBase() const& { return Current; }
NODISCARD FORCEINLINE constexpr IteratorType GetBase() && { return Current; }
private:
IteratorType Current;
};
static_assert(CRandomAccessIterator<TMoveIterator<int32*>>);
template <typename I>
TMoveIterator(I) -> TMoveIterator<I>;
/** A sentinel adaptor for use with TMoveIterator. */
template <CSemiregular S>
class TMoveSentinel
{
public:
using SentinelType = S;
FORCEINLINE constexpr TMoveSentinel() = default;
FORCEINLINE constexpr TMoveSentinel(const TMoveSentinel&) = default;
FORCEINLINE constexpr TMoveSentinel(TMoveSentinel&&) = default;
FORCEINLINE constexpr TMoveSentinel& operator=(const TMoveSentinel&) = default;
FORCEINLINE constexpr TMoveSentinel& operator=(TMoveSentinel&&) = default;
FORCEINLINE constexpr explicit TMoveSentinel(SentinelType InValue) : Last(InValue) { }
template <CSemiregular T> requires (!CSameAs<SentinelType, T> && CConvertibleTo<const T&, SentinelType>)
FORCEINLINE constexpr TMoveSentinel(const TMoveSentinel<T>& InValue) : Last(InValue.GetBase()) { }
template <CSemiregular T> requires (!CSameAs<SentinelType, T> && CConvertibleTo<const T&, SentinelType> && CAssignableFrom<SentinelType&, const T&>)
FORCEINLINE constexpr TMoveSentinel& operator=(const TMoveSentinel<T>& InValue) { Last = InValue.GetBase(); return *this; }
template <CInputIterator I> requires (CSentinelFor<SentinelType, I>)
NODISCARD FORCEINLINE constexpr bool operator==(const TMoveIterator<I>& InValue) const& { return GetBase() == InValue.GetBase(); }
template <CInputIterator I> requires (CSizedSentinelFor<SentinelType, I>)
NODISCARD FORCEINLINE constexpr TCompareThreeWayResult<SentinelType, I> operator<=>(const TMoveIterator<I>& InValue) const& { return GetBase() <=> InValue.GetBase(); }
template <CInputIterator I> requires (CSizedSentinelFor<SentinelType, I>)
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(const TMoveSentinel& Sentinel, const TMoveIterator<I>& Iter) { return Sentinel.GetBase() - Iter.GetBase(); }
template <CInputIterator I> requires (CSizedSentinelFor<SentinelType, I>)
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(const TMoveIterator<I>& Iter, const TMoveSentinel& Sentinel) { return Iter.GetBase() - Sentinel.GetBase(); }
NODISCARD FORCEINLINE constexpr const SentinelType& GetBase() const& { return Last; }
NODISCARD FORCEINLINE constexpr SentinelType GetBase() && { return Last; }
private:
SentinelType Last;
};
static_assert(CSizedSentinelFor<TMoveSentinel<int32*>, TMoveIterator<int32*>>);
template <typename I>
TMoveSentinel(I) -> TMoveSentinel<I>;
struct FDefaultSentinel { explicit FDefaultSentinel() = default; };
inline constexpr FDefaultSentinel DefaultSentinel{ };
struct FUnreachableSentinel
{
explicit FUnreachableSentinel() = default;
template<CInputOrOutputIterator I>
NODISCARD FORCEINLINE constexpr bool operator==(const I&) const& { return false; }
};
inline constexpr FUnreachableSentinel UnreachableSentinel{ };
/** An iterator adaptor that tracks the distance to the end of the range. */
template <CInputOrOutputIterator I>
class TCountedIterator final
{
public:
using IteratorType = I;
using ElementType = TIteratorElementType<I>;
# if DO_CHECK
FORCEINLINE constexpr TCountedIterator() requires CDefaultConstructible<IteratorType> : Length(1), MaxLength(0) { };
# else
FORCEINLINE constexpr TCountedIterator() requires CDefaultConstructible<IteratorType> = default;
# endif
FORCEINLINE constexpr TCountedIterator(const TCountedIterator&) = default;
FORCEINLINE constexpr TCountedIterator(TCountedIterator&&) = default;
FORCEINLINE constexpr TCountedIterator& operator=(const TCountedIterator&) = default;
FORCEINLINE constexpr TCountedIterator& operator=(TCountedIterator&&) = default;
FORCEINLINE constexpr explicit TCountedIterator(IteratorType InValue, ptrdiff N) : Current(InValue), Length(N) { check_code({ MaxLength = N; }); }
template <CInputOrOutputIterator J> requires (!CSameAs<IteratorType, J> && CConvertibleTo<const J&, IteratorType>)
FORCEINLINE constexpr TCountedIterator(const TCountedIterator<J>& InValue) : Current(InValue.GetBase()), Length(InValue.Num()) { check_code({ MaxLength = InValue.Max(); }); }
template <CInputOrOutputIterator J> requires (!CSameAs<IteratorType, J> && CConvertibleTo<const J&, IteratorType> && CAssignableFrom<IteratorType&, const J&>)
FORCEINLINE constexpr TCountedIterator& operator=(const TCountedIterator<J>& InValue) { Current = InValue.GetBase(); Length = InValue.Num(); check_code({ MaxLength = InValue.Max(); }); return *this; }
template <CInputOrOutputIterator J> requires (CSentinelFor<J, IteratorType>)
NODISCARD friend FORCEINLINE constexpr bool operator==(const TCountedIterator& LHS, const TCountedIterator<J>& RHS) { return LHS.GetBase() == RHS.GetBase(); }
template <CInputOrOutputIterator J> requires (CSizedSentinelFor<J, IteratorType>)
NODISCARD friend FORCEINLINE constexpr TCompareThreeWayResult<IteratorType, J> operator<=>(const TCountedIterator& LHS, const TCountedIterator<J>& RHS) { return LHS.GetBase() <=> RHS.GetBase(); }
NODISCARD FORCEINLINE constexpr bool operator==(FDefaultSentinel) const& { return Length == static_cast<ptrdiff>(0); }
NODISCARD FORCEINLINE constexpr strong_ordering operator<=>(FDefaultSentinel) const& { return static_cast<ptrdiff>(0) <=> Length; }
NODISCARD FORCEINLINE constexpr decltype(auto) operator*() const { CheckThis(true); return *Current; }
NODISCARD FORCEINLINE constexpr decltype(auto) operator->() const { CheckThis(true); return AddressOf(operator*()); }
NODISCARD FORCEINLINE constexpr decltype(auto) operator[](ptrdiff Index) const requires (CRandomAccessIterator<IteratorType>) { TCountedIterator Temp = *this + Index; return *Temp; }
FORCEINLINE constexpr TCountedIterator& operator++() { ++Current; --Length; CheckThis(); return *this; }
FORCEINLINE constexpr TCountedIterator& operator--() requires (CBidirectionalIterator<IteratorType>) { --Current; ++Length; CheckThis(); return *this; }
FORCEINLINE constexpr decltype(auto) operator++(int) { --Length; CheckThis(); return Current++; }
FORCEINLINE constexpr TCountedIterator operator++(int) requires (CForwardIterator<IteratorType>) { TCountedIterator Temp = *this; ++Current; --Length; CheckThis(); return Temp; }
FORCEINLINE constexpr TCountedIterator operator--(int) requires (CBidirectionalIterator<IteratorType>) { TCountedIterator Temp = *this; --Current; ++Length; CheckThis(); return Temp; }
FORCEINLINE constexpr TCountedIterator& operator+=(ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { Current += Offset; Length -= Offset; CheckThis(); return *this; }
FORCEINLINE constexpr TCountedIterator& operator-=(ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { Current -= Offset; Length += Offset; CheckThis(); return *this; }
NODISCARD friend FORCEINLINE constexpr TCountedIterator operator+(TCountedIterator Iter, ptrdiff Offset) requires (CRandomAccessIterator<IteratorType>) { TCountedIterator Temp = Iter; Temp += Offset; return Temp; }
NODISCARD friend FORCEINLINE constexpr TCountedIterator operator+(ptrdiff Offset, TCountedIterator Iter) requires (CRandomAccessIterator<IteratorType>) { TCountedIterator Temp = Iter; Temp += Offset; return Temp; }
NODISCARD FORCEINLINE constexpr TCountedIterator operator-(ptrdiff Offset) const requires (CRandomAccessIterator<IteratorType>) { TCountedIterator Temp = *this; Temp -= Offset; return Temp; }
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(const TCountedIterator& LHS, const TCountedIterator& RHS) { LHS.CheckThis(); RHS.CheckThis(); return LHS.GetBase() - RHS.GetBase(); }
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(const TCountedIterator& LHS, FDefaultSentinel) { CheckThis(); return -LHS.Num(); }
NODISCARD friend FORCEINLINE constexpr ptrdiff operator-(FDefaultSentinel, const TCountedIterator& RHS) { CheckThis(); return RHS.Num(); }
NODISCARD FORCEINLINE constexpr explicit operator ElementType*() requires (CContiguousIterator<IteratorType> && !CConst<ElementType>) { CheckThis(); return Current; }
NODISCARD FORCEINLINE constexpr explicit operator const ElementType*() const requires (CContiguousIterator<IteratorType>) { CheckThis(); return Current; }
NODISCARD FORCEINLINE constexpr const IteratorType& GetBase() const& { CheckThis(); return Current; }
NODISCARD FORCEINLINE constexpr IteratorType GetBase() && { CheckThis(); return Current; }
NODISCARD FORCEINLINE constexpr ptrdiff Num() const { CheckThis(); return Length; }
private:
IteratorType Current;
ptrdiff Length;
# if DO_CHECK
ptrdiff MaxLength;
# endif
FORCEINLINE void CheckThis(bool bExceptEnd = false) const
{
checkf(static_cast<ptrdiff>(0) <= Length && Length <= MaxLength, TEXT("Read access violation. Please check Num()."));
checkf(!(bExceptEnd && Length == static_cast<ptrdiff>(0)), TEXT("Read access violation. Please check Num()."));
}
template <CInputOrOutputIterator J>
friend class TCountedIterator;
};
static_assert(CContiguousIterator<TCountedIterator<int32*>>);
static_assert(CSizedSentinelFor<FDefaultSentinel, TCountedIterator<int32*>>);
template <typename I>
TCountedIterator(I, ptrdiff) -> TCountedIterator<I>;
template <CInvocable F, CInvocable G> requires (CReferenceable<TInvokeResult<F>> && CBooleanTestable<TInvokeResult<G>> && CMovable<F> && CMovable<G>)
class TFunctionalInputIterator final : private FNoncopyable
{
public:
using Inputer = F;
using Sentinel = G;
using ElementType = TRemoveReference<TInvokeResult<Inputer>>;
FORCEINLINE constexpr TFunctionalInputIterator() = default;
FORCEINLINE constexpr TFunctionalInputIterator(TFunctionalInputIterator&&) = default;
FORCEINLINE constexpr TFunctionalInputIterator& operator=(TFunctionalInputIterator&&) = default;
template <typename T, typename U> requires (CConvertibleTo<T, Inputer> && CConvertibleTo<U, Sentinel>)
FORCEINLINE constexpr TFunctionalInputIterator(T&& InInputer, U&& InSentinel) : InputerStorage(Forward<T>(InInputer)), SentinelStorage(Forward<U>(InSentinel)), bIsConsumed(false) { }
NODISCARD FORCEINLINE constexpr bool operator==(FDefaultSentinel) const& { return Invoke(SentinelStorage); }
NODISCARD FORCEINLINE constexpr decltype(auto) operator*() const { checkf(!bIsConsumed, TEXT("The element are consumed. Please check IsConsumed().")); bIsConsumed = true; return Invoke(InputerStorage); }
NODISCARD FORCEINLINE constexpr void operator->() const = delete;
FORCEINLINE constexpr TFunctionalInputIterator& operator++() { if (!bIsConsumed) Invoke(InputerStorage); bIsConsumed = false; return *this; }
FORCEINLINE constexpr void operator++(int) { if (!bIsConsumed) Invoke(InputerStorage); bIsConsumed = false; }
NODISCARD FORCEINLINE constexpr const Inputer& GetInputer() const& { return InputerStorage; }
NODISCARD FORCEINLINE constexpr Inputer GetInputer() && { return InputerStorage; }
NODISCARD FORCEINLINE constexpr const Sentinel& GetSentinel() const& { return SentinelStorage; }
NODISCARD FORCEINLINE constexpr Sentinel GetSentinel() && { return SentinelStorage; }
NODISCARD FORCEINLINE constexpr bool IsConsumed() const { return bIsConsumed; }
private:
Inputer InputerStorage;
Sentinel SentinelStorage;
mutable bool bIsConsumed;
};
static_assert(CInputIterator<TFunctionalInputIterator<int32(*)(), bool(*)()>>);
template <typename F, typename G>
TFunctionalInputIterator(F, G) -> TFunctionalInputIterator<F, G>;
NAMESPACE_BEGIN(Iteration)
/** Increments given iterator 'Iter' by 'N' elements. */
template <CInputIterator I>
FORCEINLINE constexpr void Advance(I& Iter, ptrdiff N)
{
if constexpr (CRandomAccessIterator<I>)
{
Iter += N;
}
else if constexpr (CBidirectionalIterator<I>)
{
for (; N > 0; --N) ++Iter;
for (; N < 0; ++N) --Iter;
}
else
{
checkf(N >= 0, TEXT("The iterator must satisfy the CBidirectionalIterator in order to be decremented."));
for (; N > 0; --N) ++Iter;
}
}
/** @return The number of hops from 'First' to 'Last'. */
template <CInputIterator I, CSentinelFor<I> S>
FORCEINLINE constexpr ptrdiff Distance(I First, S Last)
{
if constexpr (CSizedSentinelFor<I, S>)
{
return Last - First;
}
else
{
ptrdiff Result = 0;
for (; First != Last; ++First) ++Result;
return Result;
}
}
/** @return The 'N'-th successor of iterator 'Iter'. */
template <CInputIterator I>
FORCEINLINE constexpr I Next(I Iter, TMakeUnsigned<ptrdiff> N = 1)
{
Advance(Iter, N);
return Iter;
}
/** @return The 'N'-th predecessor of iterator 'Iter'. */
template <CBidirectionalIterator I>
FORCEINLINE constexpr I Prev(I Iter, TMakeUnsigned<ptrdiff> N = 1)
{
Advance(Iter, -N);
return Iter;
}
/** @return The iterator to the beginning of a container. */
template <typename T> requires (requires(T&& Container) { { Container.Begin() } -> CForwardIterator; })
FORCEINLINE constexpr decltype(auto) Begin(T&& Container)
{
return Container.Begin();
}
/** Overloads the Begin algorithm for arrays. */
template <typename T, size_t N> FORCEINLINE constexpr T* Begin( T(& Container)[N]) { return Container; }
template <typename T, size_t N> FORCEINLINE constexpr T* Begin( T(&& Container)[N]) { return Container; }
template <typename T, size_t N> FORCEINLINE constexpr const T* Begin(const T(& Container)[N]) { return Container; }
template <typename T, size_t N> FORCEINLINE constexpr const T* Begin(const T(&& Container)[N]) { return Container; }
/** Overloads the Begin algorithm for initializer_list. */
template <typename T>
FORCEINLINE constexpr decltype(auto) Begin(initializer_list<T> Container)
{
return Container.begin();
}
/** @return The iterator to the end of a container. */
template <typename T> requires (requires(T&& Container) { { Container.End() } -> CForwardIterator; })
FORCEINLINE constexpr decltype(auto) End(T&& Container)
{
return Container.End();
}
/** Overloads the End algorithm for arrays. */
template <typename T, size_t N> FORCEINLINE constexpr T* End( T(& Container)[N]) { return Container + N; }
template <typename T, size_t N> FORCEINLINE constexpr T* End( T(&& Container)[N]) { return Container + N; }
template <typename T, size_t N> FORCEINLINE constexpr const T* End(const T(& Container)[N]) { return Container + N; }
template <typename T, size_t N> FORCEINLINE constexpr const T* End(const T(&& Container)[N]) { return Container + N; }
/** Overloads the End algorithm for initializer_list. */
template <typename T>
FORCEINLINE constexpr decltype(auto) End(initializer_list<T> Container)
{
return Container.end();
}
/** @return The reverse iterator to the beginning of a container. */
template <typename T> requires (requires(T&& Container) { { Container.RBegin() } -> CForwardIterator; })
FORCEINLINE constexpr decltype(auto) RBegin(T&& Container)
{
return Container.RBegin();
}
/** Overloads the RBegin algorithm for arrays. */
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) RBegin( T(& Container)[N]) { return TReverseIterator(End(Container)); }
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) RBegin( T(&& Container)[N]) { return TReverseIterator(End(Container)); }
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) RBegin(const T(& Container)[N]) { return TReverseIterator(End(Container)); }
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) RBegin(const T(&& Container)[N]) { return TReverseIterator(End(Container)); }
/** Overloads the RBegin algorithm for T::rbegin(). */
template <typename T>
FORCEINLINE constexpr decltype(auto) RBegin(initializer_list<T> Container)
{
return TReverseIterator(Container.end());
}
/** @return The reverse iterator to the end of a container. */
template <typename T> requires (requires(T&& Container) { { Container.REnd() } -> CForwardIterator; })
FORCEINLINE constexpr decltype(auto) REnd(T&& Container)
{
return Container.REnd();
}
/** Overloads the REnd algorithm for arrays. */
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) REnd( T(& Container)[N]) { return TReverseIterator(Begin(Container)); }
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) REnd( T(&& Container)[N]) { return TReverseIterator(Begin(Container)); }
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) REnd(const T(& Container)[N]) { return TReverseIterator(Begin(Container)); }
template <typename T, size_t N> FORCEINLINE constexpr decltype(auto) REnd(const T(&& Container)[N]) { return TReverseIterator(Begin(Container)); }
/** Overloads the REnd algorithm for T::end(). */
template <typename T>
FORCEINLINE constexpr decltype(auto) REnd(initializer_list<T> Container)
{
return TReverseIterator(Container.begin());
}
NAMESPACE_END(Iteration)
#define ENABLE_RANGE_BASED_FOR_LOOP_SUPPORT public: \
NODISCARD FORCEINLINE constexpr decltype(auto) begin() { return Begin(); } \
NODISCARD FORCEINLINE constexpr decltype(auto) begin() const { return Begin(); } \
NODISCARD FORCEINLINE constexpr decltype(auto) end() { return End(); } \
NODISCARD FORCEINLINE constexpr decltype(auto) end() const { return End(); }
NAMESPACE_MODULE_END(Utility)
NAMESPACE_MODULE_END(Redcraft)
NAMESPACE_REDCRAFT_END