On Thursday, 9 February 2017 at 19:40:45 UTC, Sönke Ludwig wrote:
Am 09.02.2017 um 18:00 schrieb Kagamin:
On Wednesday, 8 February 2017 at 15:18:34 UTC, Sönke Ludwig
wrote:
The problem is that there are two affected call stacks - the
@system
API function that registers the @system callback,
wrapping/casting it
as @trusted, and the event handler that later on actually
calls the
callback. The latter place is where the hidden violation of
the @safe
guarantees happens.
Hidden from whom? Since it's user, who supplies @system code
to vibe, he
knows that the resulting program doesn't provide @safe
guarantees.
It can be communicated at the API level:
int f(@safe void delegate() dg) @safe
{ code }
int f(@system void delegate() dg) @system
{ return f(cast(@safe void delegate())dg); }
So that unsafe overload would be only callable from unsafe
code.
Hidden from the code that calls the callback. This may be an
acceptable trade off in this particular case, because this is
crossing a library border, but in general this is just misuse
of the safety system, since the effects of the cast leave the
scope of @system/@trusted.
I don't know, I don't really like this, but maybe I should just
postpone the `deprecated` attribute to be added for 0.8.1 to
leave more room for a final decision.
Just ran in to this trying to update a large project to
0.7.31-rc.2. The change to HTTPServerRequestDelegate breaks code
where we have @system callbacks that it would not be sensible to
make @trusted at the moment. What can we do?
