2.1.4 Integer Types
Microsoft C/C++ supports different sizes of integer types. An 8-bit, 16-bit, 32-bit, or 64-bit integer variable can be declared by using the __intn type specifier, where n is 8, 16, 32, or 64.
The types __int8, __int16, and __int32 are synonyms for the ANSI/ISO C types (as specified in [ISO/IEC-9899]) that have the same size. They are useful for writing portable code that behaves identically across multiple platforms.