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