Disallow implicit "conversion" from alias-types

[Jerry]

On Tuesday, 10 November 2020 at 11:38:30 UTC, Vladimirs Nordholm 
wrote:
> Hello.
>
> I am unsure if I am going about this the right way, and if my 
> question even makes sense.
>
> In essence what I want is to have two "types" represented by a 
> size_t. Here is an example of what I want think I want (but 
> might be completely off)
>
>     alias Foo = size_t;
>     alias Bar = size_t;
>
>     Foo foo = 4;
>     Bar bar = foo; // i want some error like
>                    // "cannot implicitly convert from type Foo 
> to Bar"
>
> My best solution is to have the types as classes to force type 
> checking.
>
> Is there a better way to do what I want here?

https://dlang.org/library/std/typecons/typedef.html