How do I create an UInterface?

I want to use an UInterface because I want access to InterfaceCast

// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.

#pragma once

#include "TargetInterface.generated.h"

class UTargetInterface : public UInterface

class ITargetInterface 
	virtual FString Name();

#include “TargetInterface.h”

UTargetInterface::UTargetInterface(const class FPostConstructInitializeProperties& PCIP) : Super(PCIP){


FString ITargetInterface::Name(){
	return FString("Hello World");

And I get the following error.

1> Creating library D:\unreal\ThirdPersonProject\Intermediate\Build\Win64\MyProject3Editor\Development\UE4Editor-MyProject3.lib and object D:\unreal\ThirdPersonProject\Intermediate\Build\Win64\MyProject3Editor\Development\UE4Editor-MyProject3.exp
1>MyProject3.cpp.obj : error LNK2019: unresolved external symbol “public: __cdecl UTargetInterface::UTargetInterface(class FPostConstructInitializeProperties const &)” (??0UTargetInterface@@QEAA@AEBVFPostConstructInitializeProperties@@@Z) referenced in function “void __cdecl InternalConstructor(class FPostConstructInitializeProperties const &)” (??$InternalConstructor@VUTargetInterface@@@@YAXAEBVFPostConstructInitializeProperties@@@Z)
1>D:\unreal\ThirdPersonProject\Binaries\Win64\UE4Editor-MyProject3.dll : fatal error LNK1120: 1 unresolved externals
1> -------- End Detailed Actions Stats -----------------------------------------------------------
1>ERROR : UBT error : Failed to produce item: D:\unreal\ThirdPersonProject\Binaries\Win64\UE4Editor-MyProject3.dll

Try adding __cdecl at the start of line 1.

__cdecl UTargetInterface::UTargetInterface

The linker is saying that there is a call to the function without a body, but it’s mostly correct since the compiler didn’t complain. There probably is a better way to fix it using the UE4 macros.