C++ Private Variable Robber

PrivateVariableRobber.h

#pragma once

// Tricky template trick to access private members.
// https://bloglitb.blogspot.com/2011/12/access-to-private-members-safer.html
template <typename Tag, typename Tag::Type M>
struct TRob
{
	friend typename Tag::Type Get(Tag)
	{
		return M;
	}
};

template <typename Tag, typename Member>
struct TTagBase
{
	typedef Member Type;
	friend Type Get(Tag);
};

#define DEFINE_ROBBER(ClassName, MemberType, MemberName) \
	struct F##MemberName##Tag : TTagBase<F##MemberName##Tag, MemberType ClassName::*> {}; \
	template struct TRob<F##MemberName##Tag, &ClassName::MemberName>; \
	MemberType& Access##MemberName(ClassName* Object) { return Object->*Get(F##MemberName##Tag()); }

// How to use:
// DEFINE_ROBBER(AActor, float, LastRenderTime);
// float& LastRenderTime = AccessLastRenderTime(ActorPtr);
//
// With great power comes great responsibility.
//