In classic Win32 programming for C and C++, most functions use Windows-specific typedefs and #define macros (defined in windef.h) to specify the types of parameters and return values. These Windows data types are mostly just special names (aliases) given to C/C++ built-in types. For a complete list of these typedefs and preprocessor definitions, see Windows Data Types. Some of these typedefs, such as HRESULT and LCID, are useful and descriptive. Others, such as INT, have no special meaning and are just aliases for fundamental C++ types. Other Windows data types have names that are retained from the days of C programming and 16-bit processors, and have no purpose or meaning on modern hardware or operating systems. There are also special data types associated with the Windows Runtime Library, listed as Windows Runtime base data types. In modern C++, the general guideline is to prefer the C++ fundamental types unless the Windows type communicates some additional meaning about how the value is to be interpreted.
