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

551 lines
19 KiB
C
Raw Normal View History

#pragma once
#include "CoreTypes.h"
#include "Templates/Any.h"
#include "Templates/Meta.h"
#include "Templates/Invoke.h"
#include "Memory/Alignment.h"
#include "Templates/Utility.h"
#include "TypeTraits/TypeTraits.h"
#include "Miscellaneous/AssertionMacros.h"
NAMESPACE_REDCRAFT_BEGIN
NAMESPACE_MODULE_BEGIN(Redcraft)
NAMESPACE_MODULE_BEGIN(Utility)
template <CFunction F>
class TFunctionRef;
template <CFunction F>
class TFunction;
template <CFunction F>
class TUniqueFunction;
NAMESPACE_PRIVATE_BEGIN
template <typename T> struct TIsTFunctionRef : FFalse { };
template <typename F> struct TIsTFunctionRef<TFunctionRef<F>> : FTrue { };
template <typename T> struct TIsTFunction : FFalse { };
template <typename F> struct TIsTFunction<TFunction<F>> : FTrue { };
template <typename T> struct TIsTUniqueFunction : FFalse { };
template <typename F> struct TIsTUniqueFunction<TUniqueFunction<F>> : FTrue { };
NAMESPACE_PRIVATE_END
template <typename T> concept CTFunctionRef = NAMESPACE_PRIVATE::TIsTFunctionRef<TRemoveCV<T>>::Value;
template <typename T> concept CTFunction = NAMESPACE_PRIVATE::TIsTFunction<TRemoveCV<T>>::Value;
template <typename T> concept CTUniqueFunction = NAMESPACE_PRIVATE::TIsTUniqueFunction<TRemoveCV<T>>::Value;
NAMESPACE_PRIVATE_BEGIN
template <typename T>
constexpr bool FunctionIsBound(const T& Func)
{
if constexpr (CPointer<T> || CMemberPointer<T> || CTFunctionRef<T> || CTFunction<T> || CTUniqueFunction<T>)
{
return !!Func;
}
else
{
return true;
}
}
template <typename Signature, typename F> struct TIsInvocableSignature : FFalse { };
template <typename Ret, typename... Ts, typename F>
struct TIsInvocableSignature<Ret(Ts...), F>
: TBoolConstant<CInvocableResult<Ret, F, Ts...> && CInvocableResult<Ret, F&, Ts...>>
{ };
template <typename Ret, typename... Ts, typename F> struct TIsInvocableSignature<Ret(Ts...) & , F> : TBoolConstant<CInvocableResult<Ret, F&, Ts...>> { };
template <typename Ret, typename... Ts, typename F> struct TIsInvocableSignature<Ret(Ts...) &&, F> : TBoolConstant<CInvocableResult<Ret, F , Ts...>> { };
template <typename Ret, typename... Ts, typename F>
struct TIsInvocableSignature<Ret(Ts...) const, F>
: TBoolConstant<CInvocableResult<Ret, const F, Ts...> && CInvocableResult<Ret, const F&, Ts...>>
{ };
template <typename Ret, typename... Ts, typename F> struct TIsInvocableSignature<Ret(Ts...) const& , F> : TBoolConstant<CInvocableResult<Ret, const F&, Ts...>> { };
template <typename Ret, typename... Ts, typename F> struct TIsInvocableSignature<Ret(Ts...) const&&, F> : TBoolConstant<CInvocableResult<Ret, const F , Ts...>> { };
template <typename F> struct TFunctionInfo;
template <typename Ret, typename... Ts> struct TFunctionInfo<Ret(Ts...) > { using Fn = Ret(Ts...); using CVRef = int; };
template <typename Ret, typename... Ts> struct TFunctionInfo<Ret(Ts...) & > { using Fn = Ret(Ts...); using CVRef = int&; };
template <typename Ret, typename... Ts> struct TFunctionInfo<Ret(Ts...) && > { using Fn = Ret(Ts...); using CVRef = int&&; };
template <typename Ret, typename... Ts> struct TFunctionInfo<Ret(Ts...) const > { using Fn = Ret(Ts...); using CVRef = const int; };
template <typename Ret, typename... Ts> struct TFunctionInfo<Ret(Ts...) const& > { using Fn = Ret(Ts...); using CVRef = const int&; };
template <typename Ret, typename... Ts> struct TFunctionInfo<Ret(Ts...) const&&> { using Fn = Ret(Ts...); using CVRef = const int&&; };
template <typename F, typename CVRef, bool bIsRef> class TFunctionImpl;
template <typename Ret, typename... Ts, typename CVRef, bool bIsRef>
class TFunctionImpl<Ret(Ts...), CVRef, bIsRef>
{
public:
using ResultType = Ret;
using ArgumentType = TTypeSequence<Ts...>;
TFunctionImpl() = default;
TFunctionImpl(const TFunctionImpl&) = default;
TFunctionImpl(TFunctionImpl&& InValue) = default;
TFunctionImpl& operator=(const TFunctionImpl&) = default;
TFunctionImpl& operator=(TFunctionImpl&&) = default;
~TFunctionImpl() = default;
FORCEINLINE ResultType operator()(Ts... Args) requires (CSameAs<CVRef, int >) { return CallImpl(Forward<Ts>(Args)...); }
FORCEINLINE ResultType operator()(Ts... Args) & requires (CSameAs<CVRef, int& >) { return CallImpl(Forward<Ts>(Args)...); }
FORCEINLINE ResultType operator()(Ts... Args) && requires (CSameAs<CVRef, int&&>) { return CallImpl(Forward<Ts>(Args)...); }
FORCEINLINE ResultType operator()(Ts... Args) const requires (CSameAs<CVRef, const int >) { return CallImpl(Forward<Ts>(Args)...); }
FORCEINLINE ResultType operator()(Ts... Args) const& requires (CSameAs<CVRef, const int& >) { return CallImpl(Forward<Ts>(Args)...); }
FORCEINLINE ResultType operator()(Ts... Args) const&& requires (CSameAs<CVRef, const int&&>) { return CallImpl(Forward<Ts>(Args)...); }
constexpr bool IsValid() const { return GetCallableImpl() != nullptr; }
constexpr explicit operator bool() const { return GetCallableImpl() != nullptr; }
FORCEINLINE const type_info& TargetType() const requires (!bIsRef) { return IsValid() ? Storage.GetTypeInfo() : typeid(void); };
template <typename T> FORCEINLINE T& Target() & requires (!bIsRef && CDestructible<TDecay<T>>) { return static_cast< StorageType& >(Storage).template GetValue<T>(); }
template <typename T> FORCEINLINE T&& Target() && requires (!bIsRef && CDestructible<TDecay<T>>) { return static_cast< StorageType&&>(Storage).template GetValue<T>(); }
template <typename T> FORCEINLINE const T& Target() const& requires (!bIsRef && CDestructible<TDecay<T>>) { return static_cast<const StorageType& >(Storage).template GetValue<T>(); }
template <typename T> FORCEINLINE const T&& Target() const&& requires (!bIsRef && CDestructible<TDecay<T>>) { return static_cast<const StorageType&&>(Storage).template GetValue<T>(); }
constexpr void Swap(TFunctionImpl& InValue) requires (!bIsRef)
{
using NAMESPACE_REDCRAFT::Swap;
if (!IsValid() && !InValue.IsValid()) return;
if (IsValid() && !InValue.IsValid())
{
InValue = MoveTemp(*this);
ResetImpl();
return;
}
if (InValue.IsValid() && !IsValid())
{
*this = MoveTemp(InValue);
InValue.ResetImpl();
return;
}
Swap(Storage, InValue.Storage);
}
private:
using StoragePtrType = TCopyConst<CVRef, void>*;
using CallableType = ResultType(*)(StoragePtrType, Ts&&...);
struct FunctionRefStorage
{
StoragePtrType Ptr;
CallableType Callable;
};
template <typename CallableType>
struct alignas(16) FFunctionStorage : FSingleton
{
//~ Begin CAnyCustomStorage Interface
inline static constexpr size_t InlineSize = 64 - sizeof(uintptr) - sizeof(CallableType);
inline static constexpr size_t InlineAlignment = 16;
constexpr void* InlineAllocation() { return &InlineAllocationImpl; }
constexpr const void* InlineAllocation() const { return &InlineAllocationImpl; }
constexpr void*& HeapAllocation() { return HeapAllocationImpl; }
constexpr void* HeapAllocation() const { return HeapAllocationImpl; }
constexpr uintptr& TypeInfo() { return TypeInfoImpl; }
constexpr uintptr TypeInfo() const { return TypeInfoImpl; }
constexpr void CopyCustom(const FFunctionStorage& InValue) { Callable = InValue.Callable; }
constexpr void MoveCustom( FFunctionStorage&& InValue) { Callable = InValue.Callable; }
//~ End CAnyCustomStorage Interface
union
{
uint8 InlineAllocationImpl[InlineSize];
void* HeapAllocationImpl;
};
uintptr TypeInfoImpl;
CallableType Callable;
};
using FunctionStorage = TAny<FFunctionStorage<CallableType>>;
using StorageType = TConditional<bIsRef, FunctionRefStorage, FunctionStorage>;
StorageType Storage;
FORCEINLINE CallableType& GetCallableImpl()
{
if constexpr (bIsRef) return Storage.Callable;
else return Storage.GetCustomStorage().Callable;
}
FORCEINLINE CallableType GetCallableImpl() const
{
if constexpr (bIsRef) return Storage.Callable;
else return Storage.GetCustomStorage().Callable;
}
FORCEINLINE ResultType CallImpl(Ts&&... Args)
{
checkf(IsValid(), TEXT("Attempting to call an unbound TFunction!"));
if constexpr (bIsRef) return GetCallableImpl()(Storage.Ptr, Forward<Ts>(Args)...);
else return GetCallableImpl()(&Storage, Forward<Ts>(Args)...);
}
FORCEINLINE ResultType CallImpl(Ts&&... Args) const
{
checkf(IsValid(), TEXT("Attempting to call an unbound TFunction!"));
if constexpr (bIsRef) return GetCallableImpl()(Storage.Ptr, Forward<Ts>(Args)...);
else return GetCallableImpl()(&Storage, Forward<Ts>(Args)...);
}
protected: // These functions should not be used by user-defined class
template <typename DecayedType, typename... ArgTypes>
FORCEINLINE void EmplaceImpl(ArgTypes&&... Args)
{
using FuncType = TCopyConst<TRemoveReference<CVRef>, DecayedType>;
if constexpr (bIsRef) Storage.Ptr = (AddressOf(Args), ...);
else Storage.template Emplace<DecayedType>(Forward<ArgTypes>(Args)...);
GetCallableImpl() = [](StoragePtrType Storage, Ts&&... Args) -> ResultType
{
using InvokeType = TConditional<
CReference<CVRef>,
TCopyCVRef<CVRef, FuncType>,
TCopyCVRef<CVRef, FuncType>&
>;
const auto GetFunc = [Storage]() -> InvokeType
{
if constexpr (!bIsRef) return static_cast<TCopyConst<CVRef, FunctionStorage>*>(Storage)->template GetValue<DecayedType>();
else return static_cast<InvokeType>(*reinterpret_cast<FuncType*>(Storage));
};
return InvokeResult<ResultType>(GetFunc(), Forward<Ts>(Args)...);
};
}
FORCEINLINE void AssignImpl(const TFunctionImpl& InValue)
{
if (InValue.IsValid()) Storage = InValue.Storage;
else ResetImpl();
}
FORCEINLINE void AssignImpl(TFunctionImpl&& InValue)
{
if (InValue.IsValid())
{
Storage = MoveTemp(InValue.Storage);
InValue.ResetImpl();
}
else ResetImpl();
}
constexpr void ResetImpl() { GetCallableImpl() = nullptr; }
};
NAMESPACE_PRIVATE_END
template <CFunction F>
class TFunctionRef
: public NAMESPACE_PRIVATE::TFunctionImpl<
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::Fn,
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::CVRef,
true>
{
private:
using Impl = NAMESPACE_PRIVATE::TFunctionImpl<
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::Fn,
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::CVRef,
true>;
public:
TFunctionRef() = delete;
TFunctionRef(const TFunctionRef& InValue) = default;
TFunctionRef(TFunctionRef&& InValue) = default;
TFunctionRef& operator=(const TFunctionRef& InValue) = delete;
TFunctionRef& operator=(TFunctionRef&& InValue) = delete;
template <typename T> requires (!CTFunctionRef<TDecay<T>> && !CTInPlaceType<TDecay<T>>
&& NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value)
FORCEINLINE TFunctionRef(T&& InValue)
{
using DecayedType = TDecay<T>;
checkf(NAMESPACE_PRIVATE::FunctionIsBound(InValue), TEXT("Cannot bind a null/unbound callable to a TFunctionRef"));
Impl::template EmplaceImpl<DecayedType>(Forward<T>(InValue));
}
template <typename T>
TFunctionRef(const T&&) = delete;
};
template <CFunction F>
class TFunction
: public NAMESPACE_PRIVATE::TFunctionImpl<
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::Fn,
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::CVRef,
false>
{
private:
using Impl = NAMESPACE_PRIVATE::TFunctionImpl<
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::Fn,
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::CVRef,
false>;
public:
constexpr TFunction(nullptr_t = nullptr) { Impl::ResetImpl(); }
FORCEINLINE TFunction(const TFunction& InValue) = default;
FORCEINLINE TFunction(TFunction&& InValue) : Impl(MoveTemp(InValue)) { InValue.ResetImpl(); }
FORCEINLINE TFunction& operator=(const TFunction& InValue)
{
Impl::AssignImpl(InValue);
return *this;
}
FORCEINLINE TFunction& operator=(TFunction&& InValue)
{
if (&InValue == this) return *this;
Impl::AssignImpl(MoveTemp(InValue));
return *this;
}
template <typename T> requires (!CTInPlaceType<TDecay<T>>
&& !CTFunctionRef<TDecay<T>> && !CTFunction<TDecay<T>> && !CTUniqueFunction<TDecay<T>>
&& CConstructibleFrom<TDecay<T>, T&&> && CCopyConstructible<TDecay<T>>
&& NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value)
FORCEINLINE TFunction(T&& InValue)
{
using DecayedType = TDecay<T>;
if (!NAMESPACE_PRIVATE::FunctionIsBound(InValue)) Impl::ResetImpl();
else Impl::template EmplaceImpl<DecayedType>(Forward<T>(InValue));
}
template <typename T, typename... ArgTypes> requires (NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value
&& CConstructibleFrom<TDecay<T>, ArgTypes...> && CCopyConstructible<TDecay<T>>)
FORCEINLINE TFunction(TInPlaceType<T>, ArgTypes&&... Args)
{
using DecayedType = TDecay<T>;
Impl::template EmplaceImpl<DecayedType>(Forward<ArgTypes>(Args)...);
}
constexpr TFunction& operator=(nullptr_t) { Impl::ResetImpl(); return *this; }
template <typename T> requires (NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value
&& !CTFunctionRef<TDecay<T>> && !CTFunction<TDecay<T>> && !CTUniqueFunction<TDecay<T>>
&& CConstructibleFrom<TDecay<T>, T&&> && CCopyConstructible<TDecay<T>>)
FORCEINLINE TFunction& operator=(T&& InValue)
{
using DecayedType = TDecay<T>;
if (!NAMESPACE_PRIVATE::FunctionIsBound(InValue)) Impl::ResetImpl();
else Impl::template EmplaceImpl<DecayedType>(Forward<T>(InValue));
return *this;
}
template <typename T, typename... ArgTypes> requires (NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value
&& CConstructibleFrom<TDecay<T>, ArgTypes...> && CCopyConstructible<TDecay<T>>)
FORCEINLINE TDecay<T>& Emplace(ArgTypes&&... Args)
{
using DecayedType = TDecay<T>;
Impl::template EmplaceImpl<DecayedType>(Forward<ArgTypes>(Args)...);
return Impl::template Target<DecayedType>();
}
constexpr void Reset() { Impl::ResetImpl(); }
};
template <CFunction F>
class TUniqueFunction
: public NAMESPACE_PRIVATE::TFunctionImpl<
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::Fn,
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::CVRef,
false>
{
private:
using Impl = NAMESPACE_PRIVATE::TFunctionImpl<
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::Fn,
typename NAMESPACE_PRIVATE::TFunctionInfo<F>::CVRef,
false>;
public:
constexpr TUniqueFunction(nullptr_t = nullptr) { Impl::ResetImpl(); }
FORCEINLINE TUniqueFunction(const TUniqueFunction& InValue) = delete;
TUniqueFunction(TUniqueFunction&& InValue) : Impl(MoveTemp(InValue)) { InValue.ResetImpl(); }
FORCEINLINE TUniqueFunction& operator=(const TUniqueFunction& InValue) = delete;
FORCEINLINE TUniqueFunction& operator=(TUniqueFunction&& InValue)
{
if (&InValue == this) return *this;
Impl::AssignImpl(MoveTemp(InValue));
return *this;
}
FORCEINLINE TUniqueFunction(const TFunction<F>& InValue)
: Impl(*reinterpret_cast<const TUniqueFunction*>(&InValue))
{ }
FORCEINLINE TUniqueFunction(TFunction<F>&& InValue)
: Impl(MoveTemp(*reinterpret_cast<const TUniqueFunction*>(&InValue)))
{
InValue.Reset();
}
FORCEINLINE TUniqueFunction& operator=(const TFunction<F>& InValue)
{
Impl::AssignImpl(*reinterpret_cast<const TUniqueFunction*>(&InValue));
return *this;
}
FORCEINLINE TUniqueFunction& operator=(TFunction<F>&& InValue)
{
Impl::AssignImpl(MoveTemp(*reinterpret_cast<TUniqueFunction*>(&InValue)));
return *this;
}
template <typename T> requires (!CTInPlaceType<TDecay<T>>
&& !CTFunctionRef<TDecay<T>> && !CTFunction<TDecay<T>> && !CTUniqueFunction<TDecay<T>>
&& CConstructibleFrom<TDecay<T>, T&&> && CMoveConstructible<TDecay<T>>
&& NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value)
FORCEINLINE TUniqueFunction(T&& InValue)
{
using DecayedType = TDecay<T>;
if (!NAMESPACE_PRIVATE::FunctionIsBound(InValue)) Impl::ResetImpl();
else Impl::template EmplaceImpl<DecayedType>(Forward<T>(InValue));
}
template <typename T, typename... ArgTypes> requires (NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value
&& CConstructibleFrom<TDecay<T>, ArgTypes...> && CMoveConstructible<TDecay<T>>)
FORCEINLINE TUniqueFunction(TInPlaceType<T>, ArgTypes&&... Args)
{
using DecayedType = TDecay<T>;
Impl::template EmplaceImpl<DecayedType>(Forward<ArgTypes>(Args)...);
}
constexpr TUniqueFunction& operator=(nullptr_t) { Impl::ResetImpl(); return *this; }
template <typename T> requires (NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value
&& !CTFunctionRef<TDecay<T>> && !CTFunction<TDecay<T>> && !CTUniqueFunction<TDecay<T>>
&& CConstructibleFrom<TDecay<T>, T&&> && CMoveConstructible<TDecay<T>>)
FORCEINLINE TUniqueFunction& operator=(T&& InValue)
{
using DecayedType = TDecay<T>;
if (!NAMESPACE_PRIVATE::FunctionIsBound(InValue)) Impl::ResetImpl();
else Impl::template EmplaceImpl<DecayedType>(Forward<T>(InValue));
return *this;
}
template <typename T, typename... ArgTypes> requires (NAMESPACE_PRIVATE::TIsInvocableSignature<F, TDecay<T>>::Value
&& CConstructibleFrom<TDecay<T>, ArgTypes...> && CMoveConstructible<TDecay<T>>)
FORCEINLINE TDecay<T>& Emplace(ArgTypes&&... Args)
{
using DecayedType = TDecay<T>;
Impl::template EmplaceImpl<DecayedType>(Forward<ArgTypes>(Args)...);
return Impl::template Target<DecayedType>();
}
constexpr void Reset() { Impl::ResetImpl(); }
};
template <CFunction F>
constexpr bool operator==(const TFunctionRef<F>& LHS, nullptr_t)
{
return !LHS;
}
template <CFunction F>
constexpr bool operator==(const TFunction<F>& LHS, nullptr_t)
{
return !LHS;
}
template <CFunction F>
constexpr bool operator==(const TUniqueFunction<F>& LHS, nullptr_t)
{
return !LHS;
}
static_assert(sizeof(TFunction<void()>) == 64, "The byte size of TFunction is unexpected");
static_assert(sizeof(TUniqueFunction<void()>) == 64, "The byte size of TUniqueFunction is unexpected");
NAMESPACE_PRIVATE_BEGIN
template <typename F>
struct TNotFunction
{
F Storage;
TNotFunction(const TNotFunction&) = default;
TNotFunction(TNotFunction&&) = default;
template <typename InF>
constexpr TNotFunction(InF&& InFunc) : Storage(Forward<InF>(InFunc)) { }
template <typename... Ts> requires (CInvocable<F&, Ts&&...>)
constexpr auto operator()(Ts&&... Args) &
-> decltype(!Invoke(Storage, Forward<Ts>(Args)...))
{
return !Invoke(Storage, Forward<Ts>(Args)...);
}
template <typename... Ts> requires (CInvocable<F&&, Ts&&...>)
constexpr auto operator()(Ts&&... Args) &&
-> decltype(!Invoke(MoveTemp(Storage), Forward<Ts>(Args)...))
{
return !Invoke(MoveTemp(Storage), Forward<Ts>(Args)...);
}
template <typename... Ts> requires (CInvocable<const F&, Ts&&...>)
constexpr auto operator()(Ts&&... Args) const&
-> decltype(!Invoke(Storage, Forward<Ts>(Args)...))
{
return !Invoke(Storage, Forward<Ts>(Args)...);
}
template <typename... Ts> requires (CInvocable<const F&&, Ts&&...>)
constexpr auto operator()(Ts&&... Args) const&&
-> decltype(!Invoke(MoveTemp(Storage), Forward<Ts>(Args)...))
{
return !Invoke(MoveTemp(Storage), Forward<Ts>(Args)...);
}
};
NAMESPACE_PRIVATE_END
template <typename F> requires (CConstructibleFrom<F, F&&>)
constexpr NAMESPACE_PRIVATE::TNotFunction<TDecay<F>> NotFn(F&& Func)
{
return NAMESPACE_PRIVATE::TNotFunction<TDecay<F>>(Forward<F>(Func));
}
NAMESPACE_MODULE_END(Utility)
NAMESPACE_MODULE_END(Redcraft)
NAMESPACE_REDCRAFT_END