Bug 10889 – Invariants are useless the way they are defined

Status
NEW
Severity
normal
Priority
P3
Component
dmd
Product
D
Version
D2
Platform
All
OS
All
Creation time
2013-08-25T09:07:22Z
Last change time
2024-12-13T18:10:53Z
Keywords
spec
Assigned to
No Owner
Creator
deadalnix
Moved to GitHub: dmd#18659 →

Comments

Comment #0 by deadalnix — 2013-08-25T09:07:22Z
To repeat what i posted in the newsgroup : As they are defined now, invariant are plain useless. I find myself disabling them one by one in my code as soon as cases get outside simple trivia. The problem is that invariant are checked at the beginning/end on public function calls. As a consequence, it is impossible to use any public method in an invariant. For instance, just right now I did refactor a struct to use bitfields, in order to make it more compact. Now I have to remove the invariant as field access are now function calls. Another typical situation is when you want to assert certain properties in a class hierarchy, where calling virtual method is part of the invariant check. invariant should (and must to be useful) be inserted at callee point, when the callee isn't itself subject to invariant insertion, and around public memeber manipulation (when the manipulator isn't subject to invariant insertion). Any other pattern it doomed to create infinite recursion for non trivial invariant checks.
Comment #1 by kekeniro2 — 2013-10-12T01:05:04Z
*** Issue 9412 has been marked as a duplicate of this issue. ***
Comment #2 by robert.schadek — 2024-12-13T18:10:53Z
THIS ISSUE HAS BEEN MOVED TO GITHUB https://github.com/dlang/dmd/issues/18659 DO NOT COMMENT HERE ANYMORE, NOBODY WILL SEE IT, THIS ISSUE HAS BEEN MOVED TO GITHUB