/X (Ignore Standard Include Directory)

You can prevent the compiler from searching the standard places for include files by using the /X (for “exclude”) option. When CL sees the /X option, it does not search the current directory or any directories specified in the INCLUDE environment variable.

You can use this option with the /I option to define the location of include files that have the same names as include files found in other directories but that contain different definitions. See the /I option, described earlier in this chapter, for an example of /X used with /I.