Created on 2020-06-15.00:00:00 last changed 2 weeks ago
Paper N3624 erroneously removed support for void* and function pointer relational comparisons. That ought to be restored.
Change in 7.6.9 [expr.rel] paragraph 5 as follows:
... Otherwise, the result of each of the operators is unspecified.
Prior to the adoption of paper N3624 (resolving issue 1512), comparison of void* pointers was explicitly unspecified. The current wording of 7.6.9 [expr.rel], however, describes only comparison of “pointers to objects” (paragraphs 4 and 5), but a pointer to void is not a pointer to an object, only an object pointer type (as opposed to a function pointer type). Formally, that means that comparing void* pointers is undefined behavior, which seems undesirable.
As a related note, there is implementation divergence over whether relational comparisons of void* pointers are accepted in constant expressions (when the void* values are converted from pointers that would otherwise be comparable in constant expressions).
|2022-11-20 07:54:16||admin||set||messages: + msg7050|
|2022-11-20 07:54:16||admin||set||status: open -> drafting|