Making symbols undefined in C and C++

About this task

The #undef preprocessing directive undefines symbols previously defined using the #define directive. This directive has the same effect as the following preprocessing switch:

   /U<name>

To undefine a symbol with #undef:

Procedure

  1. In the Add Preprocessing Symbol window, select the Add Symbol and Undefined radio buttons.
  2. In the Symbol field, type the name of the symbol you want to undefine.
  3. Depending on what you want to do:
    • Click Apply if you want to enter another symbol with #undef.
    • Click OK if you are done and to return to the Preprocessing tab.
  4. Click OK.

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