Floating-point TS 18661 (C23 version, 2025) issue log, r1 (N3610)

Issue Summary Status
1014 Error handling in <reduc.h> and <augarith.h> Open

Issue 1014: Error handling in <reduc.h> and <augarith.h>

Authors: Joseph Myers
Date: 2025-03-27
Status: Open

TS 18661-4:2025 talks about domain errors and range errors for functions in <reduc.h> and <augarith.h>.

In the first (2015) edition of TS 18661-4, the functions were described as being added to <math.h> so it was clear that the error handling semantics for <math.h> described in the C standard applied. With the functions now being in new headers, it is no longer clear whether those semantics (C23 7.12.2 (Treatment of error conditions)) apply to these functions, or whether different semantics might apply (such as the <complex.h> semantics where setting errno is optional even when the value of math_errhandling means it must be set by <math.h> functions).

An explicit statement should be added, either applying the rules from <math.h> to error handling for functions in the new headers, or stating how error handling requirements differ from those in <math.h>. (No specific wording is proposed here.)


Comment from Issues list maintainer on 2025-06-27:

Reflector message 30750 suggests wording to address this issue.