On Friday, 20 May 2016 at 18:42:44 UTC, Ali Çehreli wrote:
On 05/20/2016 10:28 AM, Namespace wrote: > On Thursday, 19 May 2016 at 23:21:14 UTC, Jonathan M Davis wrote: >> On Thursday, May 19, 2016 20:44:54 ciechowoj via Digitalmars-d-learn >> wrote: >>> Is there D equivalent of C++'s mutable keyword? Like the one that >>> allows to modify a field of struct from constant method. Or some >>> alternative solution? >> >> No. D's const and immutable provide no backdoors. > > But you can cheat: > ---- > int* _id; > > struct A > { > int id = 0; > > this(int id) > { > this.id = id; > _id = &this.id;Point taken but considering that D structs are freely movable value types, I don't think that's a valid D program. The spec does ban self-referencing structs but I think it also bans the code above in spirit. :)> } > > void change() const > { > (*_id)++; > } > } > > void main() { > import std.stdio; > > A a = A(42); > a.change(); > > writeln(a.id); > } > ---- Ali
Also works for classes. ;) It's valid as far as I can tell.
