How to make more better structural branded types

[falsandtru]

It can create lots of new types easily and structurally.

function build<N, T>() {
  return <{
    (a: N & T): void;
    (a: T): N & T;
  }>((a: T) => a);
}

namespace Types {
  export namespace Nominal1 {
    class Nominal<T> {
      private NOMINAL: T;
    }
    export type A = Nominal<'A'> & number;
    export const A = build<Nominal<'A'>, number>();
    export type B = Nominal<'B'> & number;
    export const B = build<Nominal<'B'>, number>();
  }
}

namespace Types {
  export namespace Nominal2 {
    class Nominal<T> {
      private NOMINAL: T;
    }
    export type A = Nominal<'A'> & number;
    export const A = build<Nominal<'A'>, number>();
    export type B = Nominal<'B'> & number;
    export const B = build<Nominal<'B'>, number>();
  }
}

var a1: Types.Nominal1.A;
var b1: Types.Nominal1.B;
var a2: Types.Nominal2.A;
a1 = b1; // error
a1 = a2; // error
a1 = Types.Nominal1.A(0); // ok
a1 = Types.Nominal1.A(a1); // error
a1 = Types.Nominal1.B(0); // error
a1 = Types.Nominal2.A(0); // error

[mhegazy]

looks like the same topic as in #4895. i suggest moving the discussion there.

[falsandtru]

This issue posted only for documentation. This is a different technique, and has a different purpose from #4895.

[mhegazy]

This issue posted only for documentation. This is a different technique, and has a different purpose from #4895.

I understand; #4895 is a discussion item that is meant for brainstorming and sharing ideas.