const?? When and why? This is ugly!

[Lutger]

hasen wrote:

> hasen wrote:
>> I haven't been following D for over a year .. now I notice there's a 
>> const!!
>> 
>> [...]
> 
> It seems the argument is centered around making "pure functions" possible.
> 
> But, surely there's a better way of doing this than borrowing const from 
> C++.

Reading the docs you must have noticed the difference between C++ const and 
D. In D, const and immutable are transitive, in C++ they are not. D has 
immutable, C++ does not. These two are the most important concepts and make 
the D design that much different, you can't seriously claim it is borrowed 
from C++. 

Const in C++ is (merely) a compiler aided documentation tool, whereas 
const+immutable in D are the basis of a functional programming niche inside 
D.