Compiling to 64-bit

[Techno-Logic]

Unfortunately, I find a little information on MSDN library about porting to 64-bit.

I wonder how to compile for 64-bit OS in VC++.NET.

In that case, I changed the preprocessor definitions of my project to _WIN64, but the compiler annoyed me that size_t is redefined in <new.h>
I opened the new.h and in the middle of the file, these several lines took my attention:

#ifndef _SIZE_T_DEFINED
#ifdef _WIN64
typedef unsigned __int64 size_t;
#else
typedef _W64 unsigned int size_t;
#endif
#define _SIZE_T_DEFINED
#endif

I couldn`t understand the exact problem. But, I think I did something incomplete.

Please help!