How to get child class Type and members from parent class?

[Jacob Carlborg]

On Wednesday, 20 November 2019 at 10:05:11 UTC, zoujiaqing wrote:
> import std.stdio;
>
>
> class A
> {
>     this(T)(T t)
>     {
>
>     }
>
>     void write()
>     {
>         T _this = cast(T) this;
>         writeln(this.v);
>     }
> }
>
> class B : A
> {
>     string v = "hello";
> }
>
> void main()
> {
>     auto b = new B;
>
>     writeln(b.write()); // print hello
> }

You can use a template this parameter [1], like this:

import std.stdio;

class A
{
     void write(this T)()
     {
         T self = cast(T) this;
         writeln(self.v);
     }
}

class B : A
{
     string v = "hello";
}

void main()
{
     auto b = new B;
     b.write();
}

[1] https://dlang.org/spec/template.html#template_this_parameter

--
/Jacob Carlborg