The #error Directive

Error directives produce compiler-time error messages.

#error token-string

Remarks

The error messages include the argument token-string and are currently not subject to macro expansion. These directives are most useful for detecting programmer inconsistencies and violation of constraints during preprocessing. The following example demonstrates error processing during preprocessing:

#if !defined(__cplusplus)
#error C++ compiler required.
#endif

When #error directives are encountered, compilation terminates.

See Also

Concepts

Preprocessor Directives