Controls the recognition of unreferenced variables.
#pragma warn_unusedvar on | off | reset
If you enable this pragma, the compiler issues a warning when it encounters a variable you declare but do not use. To suppress this warning in C++ source code, leave an argument identifier out of the function parameter list.
This pragma corresponds to the Unused Variables setting in the Language panel. To check this setting, use __option (warn_unusedvar), described in Checking Pragma Settings. By default, this pragma is disabled.