On Monday, 15 February 2016 at 23:39:56 UTC, ZombineDev wrote:
On Monday, 15 February 2016 at 23:28:28 UTC, Walter Bright
wrote:
On 2/15/2016 3:11 PM, ZombineDev wrote:
I'll leave to others to discuss whether a language solution
is worth it, but I
just wanted to point out there are two library solutions in
this area:
HeadConst [1] - PR pending, and
Rebindable (tail const) [2] - already part of Phobos.
Maybe if the language could express head const, it also makes
sense to have tail
const.
[1]:
https://github.com/D-Programming-Language/phobos/pull/3862
[2]:
http://dlang.org/phobos-prerelease/std_typecons.html#.Rebindable
Transitive const is tail const.
I used the term "tail const" as a mutable pointer/reference to
const/immutable object, where transitivity starts from the
object (not from the pointer, which is what currently happens
if you type `const Object o`).
Just to clarify:
struct S;
const(S)* mutablePointerToS;
const(S)[] mutableArrayOfConstObjects;
Are examles of tail const. The only missing piece is the ability
to have a tail-const references to class objects.
