#error directive (C/C++)

The #error directive emits a user-specified error message at compile time. Then it terminates the compilation.

Syntax

#error token-string

Remarks

The error message that this directive emits includes the token-string parameter. The token-string parameter is not subject to macro expansion. This directive is most useful during preprocessing, to notify the developer of a program inconsistency, or the violation of a constraint. The following example demonstrates error processing during preprocessing:

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

See also

Preprocessor directives
#warning directive