digitalmars.D.bugs - [Issue 24566] New: condition that starts with runtime value and uses
- d-bugmail puremagic.com (34/34) May 24 https://issues.dlang.org/show_bug.cgi?id=24566
https://issues.dlang.org/show_bug.cgi?id=24566 Issue ID: 24566 Summary: condition that starts with runtime value and uses compile time array does not short circuit Product: D Version: D2 Hardware: All OS: All Status: NEW Keywords: rejects-valid Severity: normal Priority: P1 Component: dmd Assignee: nobody puremagic.com Reporter: schveiguy gmail.com If I mix a runtime and compile time expression in a condition, short circuiting doesn't prevent a compile-time bounds check for constant folded arrays. ```d enum a = true; bool b = true; enum str = "a"; if(a && str.length > 1 && str[1] == 'a') {} // ok if(b && str.length > 1 && str[1] == 'a') {} // compiler error if(!b && str.length > 1 && str[1] == 'a') {} // compiler error if(str.length > 1 && b && str[1] == 'a') {} // ok ``` The error is: Error: string index 1 is out of bounds [0 .. 1] If the runtime condition is not first, then it compiles. Note that even if the runtime condition is false and should short circuit the whole thing, the compiler still errors. As far as I can tell, this has always been the case, so not a regression. Though a related issue might be issue 22646. --
May 24