Share via

#error directive (C/C++)

The #error directive emits a user-specified error message at compile time, and then terminates the compilation.


#error token-string


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.

See also

Preprocessor directives