U

Undefines any definition currently in effect for the specified macro.

IDE Equivalent

Windows: Preprocessor > Undefine Preprocessor Definitions

Linux: Preprocessor > Undefine Preprocessor Definitions

OS X: Preprocessor > Undefine Preprocessor Definitions

All

Linux and OS X:

-Uname

Windows:

/Uname

name

Is the name of the macro to be undefined.

OFF	Macro definitions are in effect until they are undefined.

This option undefines any definition currently in effect for the specified macro. It is equivalent to an #undef preprocessing directive.

On Windows systems, use the /u option to undefine all previously defined preprocessor values.

None

To undefine a macro, enter the following command:

On Windows* systems:

icl -Uia32 prog1.cpp

On Linux* and OS X* systems:

icpc -Uia32 prog1.cpp

If you attempt to undefine an ANSI C macro, the compiler will emit an error:

invalid macro undefinition: <name of macro>