Strange error with templates and inheritance.

[Robert Fraser]

Frank Fischer Wrote:

> Hi,
> 
> i'm currently developing a library and I heavily use templates and multiple
> inheritance (of interfaces, of course). The following inheritance structure
> is used (I removed all methods that are not important to show the error):
> 
> ---
> module mytest;
> 
> import std.stdio;
> 
> interface A(T) {
>     C!(T) func();
>     size_t f();
> }
> 
> abstract class B(T): A!(T) {
> }
> 
> interface C(T): A!(T) {
> }
> 
> class D: B!(int), C!(int) {
>     size_t f() { return 42; }
>     C!(int) func() { return this; }
> }
> 
> void main() {
>     A!(int) x = new D();
>     writefln("%d", x.f());
> }
> ---
> 
> When I compile this snippet with dmd 2.003 on my linux-box, I get a
> segmentation fault on the call "x.f()" in the last line. Furthermore, if I
> use an interface instead of an abstract class for B, everything is fine.
> Even if I just change the order of definition of 'func' and 'f' in A, i.e.
> 
> interface A(T) {
>     size_t f();
>     C!(T) func();
> }
> 
> everything works. 
> 
> Can anyone reproduce this error and/or explain it? In my library I
> can't/want to change B into an interface, because the class should contain
> some methods.
> 
> Thanks,
> Frank
> 

Sounds like a bug. You have your minimal code sample there, report it.