https://d.puremagic.com/issues/show_bug.cgi?id=11858
Summary: Comparison of unconnected classes using `is` must be
disallowed
Product: D
Version: D2
Platform: All
OS/Version: All
Status: NEW
Keywords: accepts-invalid
Severity: major
Priority: P2
Component: DMD
AssignedTo: [email protected]
ReportedBy: [email protected]
--- Comment #0 from Denis Shelomovskij <[email protected]> 2014-01-02
19:49:31 MSK ---
Comparison of unconnected classes using `is` is definitely a mistake. If one
want to do such raw things for some reason, he has to cast to e.g. `Object` or
`void*` first. Currently such construction is allowed even in `@safe` code.
This code should compile:
---
class A { }
class B { }
void main()
{
A a;
B b;
static assert(!__traits(compiles, a is b)); // fails
}
---
As a result of the issue it's to easy to make a mistake like `a.prop1 is b`
instead of `a.prop1.owner is b`. Also a refactoring of class hierarchy by
segregating subclasses becomes a nightmare as you get no errors from type
system in situations when you e.g. forget to change `find` predicate.
--
Configure issuemail: https://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
