Windows® via C/C++, Fifth Edition

Unicode and ANSI Functions in Windows

Since Windows NT, all Windows versions are built from the ground up using Unicode. That is, all the core functions for creating windows, displaying text, performing string manipulations, and so forth require Unicode strings. If you call any Windows function passing it an ANSI string (a string of 1-byte characters), the function first converts the string to Unicode and then passes the Unicode string to the operating system. If you are expecting ANSI strings back from a function, the system converts the Unicode string to an ANSI string before returning to your application. All these conversions occur invisibly to you. Of course, there is time and memory overhead involved for the system to carry out all these ...