On Tuesday, 13 November 2012 at 08:50:16 UTC, Rob T wrote:
> Hard to describe this problem, see code and read comments below.
>
> class A
> {
> private int _v;
>
> this( int a_v )
> {
> _v = a_v;
> }
>
> @property size_t length()
> {
> return 1;
> }
> int opApply( int delegate( ref int a_v ) a_dg )
> {
> int result = 0;
> for ( ulong i = 0; i < length; ++i )
> {
> result = a_dg( this.opIndex( i ) );
> if ( result ) break;
> }
> return result;
> }
> ref int opIndex( size_t a_iPos )
> {
> return _v;
> }
>
> }
>
> class B : A
> {
> this( int a_v )
> {
> super(a_v);
> }
>
> ref int find( int a_What )
> {
> foreach( val; super )
> {
> if ( val == a_What )
> return val;
> }
> throw new Exception("value not found");
> }
> }
>
> main()
> {
> auto v_B = new B(500);
> writefln("Search = %d", v_B.find(500) );
> return 0;
> }
>
>
> When the return value of find() is ref, it segfaults or returns
> garbage. If the return value is a copy it works OK.
>
> The only oddity I can see is that 'val' goes out of scope, but
> it's a ref return value (pointer) to _v (right?), so it should
> work anyway.
>
> This looks like a bug in the compiler to me.
>
> What do you guys think?
This issue looks like bug8093.
http://d.puremagic.com/issues/show_bug.cgi?id=8093
And the code works correctly in git head (dmd2.061alpha).
Therefore, I think that the bug is fixed very recently.
Kenji Hara