On Tuesday, 22 September 2020 at 18:21:10 UTC, Jacob Carlborg
wrote:
On 2020-09-19 21:50, Per Nordlöw wrote:
On Saturday, 19 September 2020 at 18:48:31 UTC, Jacob Carlborg
wrote:
A nested class seems to be able to escape the `this`
reference:
Ahh, thanks.
I just realized that it can escape into other parameters
without the `scope` qualifier?
This
class Bar
{
void bar(scope Bar b) @safe pure
{
b = this;
}
}
compiles but this
class Bar
{
scope void bar(scope Bar b) @safe pure
{
b = this; // Error: scope variable `this` assigned to
`b` with longer lifetime
}
}
Hmm, why would `b` have longer lifetime? Isn't the lifetime of
`b` throughout `bar`?
The following analysis might be wrong but I think that `scope` as
a **member** function attribute is not supposed to be used as
that is not even documented.
So it would works "by default". The compiler thinks that `this`
is a scope variable that will stop living after `bar()`.
Also as `b` is not `ref` this is clearly a wrong diagnostic.
There's a special case missing in the compiler.
