huh this seems a lot like c++. im guessing that immutable is const, line 8 would be a string*. is the function like in php then, when it just skips the function until called? does ~ cat strings on line 51? whats to!string(n)?
why do you have a function within another function, also D actually looks quite amazing. The day they allow it in computer olympiads is the day I will start using it though.
It is "crude" as you say, but why are you posting it? For review? help?
Although come to think of it, it is not that crude: It has a pretty good defensive design and it generates a completely random password. You could try and make it ensure that there are a certain amount of each type of character.