On Sat, Jul 12, 2014 at 09:30:44PM -0700, H. S. Teoh via Digitalmars-d-learn
wrote:
> On Sat, Jul 12, 2014 at 09:20:06PM -0700, Ali Çehreli via Digitalmars-d-learn
> wrote:
[...]
> > The twist here is that the OP's function returned 'this' by
> > reference. Changing that not only not have any effect on the
> > object, it would also be undefined behavior because 'this' is a
> > local variable in that use.
> >
> > class C {
> > ref C getPtr() { return this; }
> > }
> >
> > void main()
> > {
> > auto c = new C();
> > assert(c.getPtr() is c);
> >
> > c.getPtr() = new C(); // modifying dead variable
> > assert(c.getPtr() is c); // no effect
> > }
> [...]
>
> Hmm. Shouldn't this be a compiler bug?? Returning a ref to a local
> variable should be illegal, even implicit ones like 'this'.
[...]
Filed as bug:
https://issues.dlang.org/show_bug.cgi?id=13116
It's pretty serious, since it causes memory corruption. In fact, it also
breaks @safe-ty (see second bug note in above link).
T
--
The early bird gets the worm. Moral: ewww...
