Non-null objects, the Null Object pattern, and T.init

[inout]

On Friday, 17 January 2014 at 02:52:15 UTC, bearophile wrote:
> deadalnix:
>
>> Most object don't have a sensible init value. That is just 
>> hiding the problem under the carpet.
>
> If there's desire to solve this problem I think that improving 
> the type system to avoid nulls where they are not desired is 
> better than having an init object.
>
> So aren't not-nullable pointers and references a better 
> solution?
>
> Bye,
> bearophile

This! Also, if anything, it's better to turn `init` into a method
rather than an object. The following would work all of a sudden:

class Foo
{
     Bar bar = new Bar();
     int i = 42;

     Foo() {
        assert(bar !is null);
        assert(i == 42);
     }

     // auto-generated
     private final void init(Foo foo) {

        foo.bar = new Bar();
        foo.i = 42;
     }
}