Windows Runtime unsupported CRT functions
Many C run-time (CRT) APIs can't be used in Universal Windows Platform (UWP) apps that execute in the Windows Runtime. These apps are built by using the /ZW compiler flag. For a list of unsupported CRT functions, see CRT functions not supported in Universal Windows Platform apps.
All CRT APIs are described in the Alphabetical function reference section of the documentation.
Universal C runtime routines by category
Alphabetical function reference