Builder: Tiny Utility Library to Add a Builder API to Classes

[thebluepandabear]

On Friday, 6 January 2023 at 12:54:07 UTC, Vijay Nayar wrote:
> On Friday, 6 January 2023 at 09:26:51 UTC, thebluepandabear 
> wrote:
>>>   .isActive(true)
>>>   .build();
>>> ```
>>
>> Good 👍
>>
>> how would I extend the builder methods?
>
> The builder methods are automatically generated and go up the 
> inheritance chain to capture all the fields in your class. (I 
> assume that you are referring to inheritance when you say 
> "extend"?)
>
> Here is one of the unit-tests demonstrating this:
>
> ```
> class A2 {
>   int a;
>   string b;
> }
>
> class B2 : A2 {
>   int c;
>
>   mixin AddBuilder!(typeof(this));
> }
>
> /// All inherited fields should be available from the builder.
> unittest {
>   B2 b2 = B2.builder()
>       .a(3)
>       .b("ham")
>       .c(4)
>       .build();
>
>   assert(b2.a == 3);
>   assert(b2.b == "ham");
>   assert(b2.c == 4);
> }
> ```

I meant what if I want some extra behavior for the setter method 
other than just assigning a value to the field. E.g. if I set a 
password field, I might want to validate that it's valid.