Safest hack to access private data of a C++ class

access_private_member.cpp

/*
 Access C++ Private Member
 License: Public Domain (www.unlicense.org)
 Based on http://cpp.kjx.cz/private_backdoor.html which itself is based on http://bloglitb.blogspot.com/2011/12/access-to-private-members-safer.html
*/

#include <stdio.h>

class CSafe
{
	int data;
};

namespace CSafePrivate
{
	template<int CSafe::*MEMBER_PTR> struct _DataTemplate
	{
		inline friend int& Data(CSafe& obj) { return obj.*MEMBER_PTR; }
	};
	template struct _DataTemplate<&CSafe::data>;
	inline int& Data(CSafe& obj);
}

int main()
{
	CSafe a;
	CSafePrivate::Data(a) = 20;
	printf("Data: %d\n", CSafePrivate::Data(a));
	return 0;
}