On Tuesday, 6 March 2018 at 12:00:43 UTC, Steven Schveighoffer
wrote:
On 3/6/18 6:21 AM, Simen Kjærås wrote:
On Tuesday, 6 March 2018 at 10:03:54 UTC, Shachar Shemesh
wrote:
void main() {
struct S {
uint value;
~this() {
}
}
const S a = S(12);
S b = a;
}
test.d(10): Error: cannot implicitly convert expression a of
type const(S) to S
Looks like a bug to me - please file one in bugzilla.
Nope. It's not a bug. S contains a pointer, namely the context
pointer for main.
It's a bug. As pointed out elsewhere in this thread, it compiles
correctly when there's no destructor. Essentially, this bug is
caused by the context pointer being typed as void*, and becoming
(of course) const(void*) for a const(S). If it'd been
const(void)* in the first place, Shachar's code would have
compiled and worked correctly.
Is it misleading for the context pointer to be const(void)*? In a
way, maybe. However, it's opaquely typed, and its constness says
nothing about what's on the other end. Also, the language
completely disregards the constness in any case:
unittest {
int i = 0;
struct S {
int n;
void fun() const {
i++;
}
}
const S s;
assert(i == 0);
s.fun();
assert(i == 1);
}
--
Simen
