|Synopsis:||The #error directive should be used with caution.|
Its effect can be achieved by the following:
error: This should not happen
#error: This should not happen
Although both methods will cause an error to be reported by the C compiler, the second form can “choke” a pre-ANSI preprocessor that doesn’t recognise the directive even when the directive is skipped as part of a #if group. The first form will always get through a preprocessor correctly.