Re: Automatic method overriding in sub-classes

[Daniel N via Digitalmars-d]

On Thursday, 29 October 2015 at 13:54:17 UTC, bitwise wrote:

class One : Base!One { }
class Two : Base!Two { }

Doesn't work with multiple levels of inheritance...

    Bit

Just sprinkle some D magic ontop.. voilà DRTP is born ;)

template Dynamic(T)
{
  static if(is(T == U!V, alias U, V))
    alias Dynamic = Dynamic!V;
  else
    alias Dynamic = T;
}

interface IBase { string Name(); }

class Base(T) : IBase
{
  final string Name()
  {
    auto self = cast(Dynamic!T)this;

    return self.me; // Dynamic!T.stringof;
  }
}

class One(T...) : Base!One { string me = "1";}
class Two(T...) : Base!Two { string me = "2";}
class Six(T...) : One!Six  { string me = "6";}
class Ten(T...) : Six!Ten  { string me = "a";}

void main()
{
  import std.stdio;

  IBase one = new One!();
  IBase two = new Two!();
  IBase six = new Six!();
  IBase ten = new Ten!();

  one.Name.writeln;
  two.Name.writeln;
  six.Name.writeln;
  ten.Name.writeln;
}