How can I make typeof(this) return the type of a calling derrived class from a function in a base class?

[Adam D. Ruppe via Digitalmars-d-learn]

On Friday, 16 June 2017 at 13:46:14 UTC, Lester wrote:
> If I have something like the following:
>
> class A {
>     void foo(){ writeln(typeof(this)); }

try one of these:

http://dlang.org/spec/template.html#TemplateThisParameter


Though note that the this in there is still the static type at 
the usage point. So:

B b = new B;
b.foo; // B, because it is called through a B

but

A b = new B;
b.foo; // A, because it is called through the A interface


You can also do runtime stuff with typeid/classinfo (they return 
the same thing) or simply override the function in the child 
class (often preferred). Depends on exactly what you need it for.