(D1) Mixing in constructors
Justin Whear
justin at economicmodeling.com
Fri Nov 6 09:47:59 PST 2009
I've been trying to use a template to mixin constructors and running into what seems like a bug. Here's the template:
public template ChainNodeSubclassing {
this() {
super();
}
this(string id) {
super(id);
}
...some other stuff...
}
Using this, compilation would always fail and complain that Object has no super class. This is strange because template mixins are supposed to only be evaluated where they're mixed-in, namely in the body of my classes which certainly do have super-classes.
So I tried getting around it like this (just the second constructor for brevity):
this(string id) {
static if (!is(typeof(this) : Object))
{
super(id);
writefln("Instantiating %s with ID", this.classinfo.name);
} else {
throw new Exception("Cannot instantiate type");
}
}
Now it compiles, but I always get errors at runtime when I try to create of one the classes with this mixin. It seems that every object is implicitly convertible to Object. Is this a bug or am I doing something really wrong?
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