Article about problems & suggestions for D 2.0

[Kagamin]

Mehrdad Wrote:

> I feel like you hit the nail on the head. I feel the same way about const.
> 
> Transitivity is beautiful on the outside, but I can never actually get 
> it working, so I just make everything non-const. I have to sometimes do 
> this even in Phobos itself, because the compiler complains about 
> something random caused by transitivity.
> I also fail to see what /problem/ it's trying to solve. The DigitalMars 
> website simply states:
> 
> "With transitivity, there is no way to have a const pointer to mutable int."
> 
> But... so what? Maybe it should actually explain the benefit, since I 
> can't figure it out on my own. (The related discussion on "head-const" 
> and "tail-const" seems completely irrelevant to the topic."
> 
> C++'s non-transitivity seems to be quite type-safe, even if unintuitive 
> to the beginner (which I don't think it is). I *never* ran into issues 
> with it.

In C I had to cast away const because constness is built into the struct itself - if you want the struct to be accessed as readonly. In D transitive const is transparent - you can have the save structure both readonly and mutable.