Invoke.h File Reference

#include "CoreTypes.h"
#include "Traits/MemberFunctionPtrOuter.h"
#include "Templates/UnrealTemplate.h"
#include <type_traits>

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Classes
struct	UE::Core::Private::TInvokeResult_Impl< typename, FuncType, ArgTypes >
struct	UE::Core::Private::TInvokeResult_Impl< decltype((void) Invoke(DeclVal< FuncType >(), DeclVal< ArgTypes >()...)), FuncType, ArgTypes... >
struct	TInvokeResult< FuncType, ArgTypes >

Namespaces
namespace	UE
namespace	UE::Core
namespace	UE::Core::Private

Macros
#define	UE_PROJECTION(FuncName)
#define	UE_PROJECTION_MEMBER(Type, FuncName)

Typedefs
template<typename FuncType , typename... ArgTypes>
using	TInvokeResult_T = typename TInvokeResult<FuncType, ArgTypes...>::Type

Functions
template<typename OuterType , typename TargetType >
FORCEINLINE auto	UE::Core::Private::DereferenceIfNecessary (TargetType &&Target, const volatile OuterType *TargetPtr) -> decltype((TargetType &&) Target)
template<typename OuterType , typename TargetType >
FORCEINLINE auto	UE::Core::Private::DereferenceIfNecessary (TargetType &&Target,...) -> decltype(*(TargetType &&) Target)
template<typename FuncType , typename... ArgTypes>
FORCEINLINE auto	Invoke (FuncType &&Func, ArgTypes &&... Args) -> decltype(Forward< FuncType >(Func)(Forward< ArgTypes >(Args)...))
template<typename ReturnType , typename ObjType , typename TargetType >
FORCEINLINE auto	Invoke (ReturnType ObjType::*pdm, TargetType &&Target) -> decltype(UE::Core::Private::DereferenceIfNecessary< ObjType >(Forward< TargetType >(Target), &Target).*pdm)
template<typename PtrMemFunType , typename TargetType , typename... ArgTypes, typename ObjType = TMemberFunctionPtrOuter_T<PtrMemFunType>>
FORCEINLINE auto	Invoke (PtrMemFunType PtrMemFun, TargetType &&Target, ArgTypes &&... Args) -> decltype((UE::Core::Private::DereferenceIfNecessary< ObjType >(Forward< TargetType >(Target), &Target).*PtrMemFun)(Forward< ArgTypes >(Args)...))

Macro Definition Documentation

UE_PROJECTION

#define UE_PROJECTION

(

FuncName

)

Value:

    [](auto&&... Args) -> decltype(auto) \
    { \
        return FuncName(Forward<decltype(Args)>(Args)...); \
    }

Wraps up a named non-member function so that it can easily be passed as a callable. This allows functions with overloads or default arguments to be treated correctly.

Example:

TArray<FMyType> Array = ...;

// Doesn't compile, because you can't take the address of an overloaded function when its type needs to be deduced. Algo::SortBy(Array, &LexToString);

// Works as expected Algo::SortBy(Array, UE_PROJECTION(LexToString));

Definition at line 84 of file Invoke.h.

UE_PROJECTION_MEMBER

#define UE_PROJECTION_MEMBER	(		Type,
			FuncName )

Value:

    [](auto&& Obj, auto&&... Args) -> decltype(auto) \
    { \
        return UE::Core::Private::DereferenceIfNecessary<Type>(Forward<decltype(Obj)>(Obj), &Obj).FuncName(Forward<decltype(Args)>(Args)...); \
    }

Wraps up a named member function so that it can easily be passed as a callable. This allows functions with overloads or default arguments to be treated correctly.

Example:

TArray<UObject*> Array = ...;

// Doesn't compile, because &UObject::GetFullName loses the default argument and passes // FString (UObject::*)(const UObject*) to Algo::SortBy<>(), which is not a valid projection. Algo::SortBy(Array, &UObject::GetFullName);

// Works as expected Algo::SortBy(Array, UE_PROJECTION_MEMBER(UObject, GetFullName));

Definition at line 105 of file Invoke.h.

Typedef Documentation

TInvokeResult_T

template<typename FuncType , typename... ArgTypes>

using TInvokeResult_T = typename TInvokeResult<FuncType, ArgTypes...>::Type

Definition at line 135 of file Invoke.h.

Function Documentation

Invoke() [1/3]

template<typename FuncType , typename... ArgTypes>

FORCEINLINE auto Invoke	(	FuncType &&	Func,
		ArgTypes &&...	Args ) -> decltype(Forward<FuncType>(Func)(Forward<ArgTypes>(Args)...))

Invokes a callable with a set of arguments. Allows the following:

• Calling a functor object given a set of arguments.
• Calling a function pointer given a set of arguments.
• Calling a member function given a reference to an object and a set of arguments.
• Calling a member function given a pointer (including smart pointers) to an object and a set of arguments.
• Projecting via a data member pointer given a reference to an object.
• Projecting via a data member pointer given a pointer (including smart pointers) to an object.

See: http://en.cppreference.com/w/cpp/utility/functional/invoke

Definition at line 44 of file Invoke.h.

Invoke() [2/3]

template<typename PtrMemFunType , typename TargetType , typename... ArgTypes, typename ObjType = TMemberFunctionPtrOuter_T<PtrMemFunType>>

FORCEINLINE auto Invoke	(	PtrMemFunType	PtrMemFun,
		TargetType &&	Target,
		ArgTypes &&...	Args ) -> decltype((UE::Core::Private::DereferenceIfNecessary<ObjType>(Forward<TargetType>(Target), &Target).*PtrMemFun)(Forward<ArgTypes>(Args)...))

Definition at line 63 of file Invoke.h.

Invoke() [3/3]

template<typename ReturnType , typename ObjType , typename TargetType >

FORCEINLINE auto Invoke	(	ReturnType ObjType::*	pdm,
		TargetType &&	Target ) -> decltype(UE::Core::Private::DereferenceIfNecessary<ObjType>(Forward<TargetType>(Target), &Target).*pdm)

Definition at line 51 of file Invoke.h.