Class qualifier vs struct qualifier

[Steven Schveighoffer]

On 6/13/18 3:35 AM, RazvanN wrote:
> Hello,
> 
> I'm having a hard time understanding whether this inconsistency is a bug 
> or intended behavior:
> 
> immutable class Foo {}
> immutable struct Bar {}
> 
> void main()
> {
>      import std.stdio : writeln;
>      Foo a;
>      Bar b;
> 
>      writeln("typeof(a): ", typeof(a).stringof);
>      writeln("typeof(b): ", typeof(b).stringof);
> }
> 
> prints:
> 
> typeof(Foo): Foo
> typeof(Bar): immutable(Bar)
> 
> 
> It seems like the class storage class is not taken into account which 
> leads to some awkward situations like:
> 
> immutable class Foo
> {
>      this() {}
> }
> 
> void main()
> {
>      Foo a = new Foo(); // error: immutable method `this` is not 
> callable using a
>                         // mutable object
> }
> 
> To make it work I have to add immutable to both sides of the expression 
> : immutable Foo a = new immutable Foo(); this is a wonder of redundancy. 
> I already declared the class as immutable so it shouldn't be possible to 
> have mutable instances of it (and it isn't), however I am forced to 
> write the immutable twice even though it is pretty obvious that the 
> class cannot be mutated.

Just on the principle of least surprise, I'd call this a bug. I don't 
know what the intention is, but if the intention is for this behavior, 
we should re-visit.

-Steve