How to get the type of a derived class in a method of its base class?

[biozic via Digitalmars-d-learn]

On Sunday, 19 February 2017 at 07:52:13 UTC, Max Samukha wrote:
> class A {
>     this(T = this)() {
>         static assert(is(T == B));
>     }
> }
>
> class B {
> }
>
> auto b = new B;
>
> Here, T becomes A, which may be reasonable but is completely 
> useless. Is there a way to obtain the type of the class (or 
> class instance reference) the method is called on?

Not at compile time:

class A
{
     this()
     {
         assert(typeid(this) == typeid(B));
     }
}

class B : A
{
}

auto b = new B;