C++ mutable in D

[Paulo Pinto]

On Sunday, 1 August 2021 at 06:15:30 UTC, Jack Applegame wrote:
> On Friday, 30 July 2021 at 20:09:19 UTC, Tejas wrote:
>> Also remember that casting away const is undefined behaviour 
>> in D (unlike being defined and supported in C++).
>
> No.
> Casting const away IS NOT undefined behavior in both D and C++.
> Modifying a const object IS undefined behavior in both D and 
> C++.
> There is not much difference between D and C++ in that way.

Not in C++, when the const object modification is taking place 
via member variables declared as mutable accessed from a const 
member function.

This is also a thing in Swift and Rust, by the way, they just use 
other mechanisms to do the same.