Le 29/01/11 03:51, Jonathan M Davis a écrit :
On Friday 28 January 2011 13:55:03 Jonathan M Davis wrote:
On Friday, January 28, 2011 10:57:58 biozic wrote:
Hi,
I am playing with the to-be-released std.datetime, and encountered these
errors (the last one concerns std.variant, actually), with dmd 2.052
(Mac OS X 10.6):
---
import std.array, std.datetime, std.variant;
unittest {
auto app = appender!(Interval!Date[]);
auto interval = Interval!Date(Date(2000, 1, 1), Date(2011, 2, 3));
app.put(interval);
// Error: datetime.d(20208): Invariant Failure: begin is not before
or equal to end.
}
There no known bugs in std.datetime. My guess would be that the issue lies
with appender and Interval!(Date).init and/or something set to void if
appender does that at all. But since Date.init would be equal to
Date.init, it seems extremely bizarre that Interval!(Date).init would have
its begin and end not be equal, which makes it less likely that
Interval!(Date).init would be the problem. So, I don't know. The code is
very thoroughly tested, but that doesn't mean that I didn't miss
something, and it's possible that there's a bug in appender. I'm not at
all familiar with how appender works. I'll have to take a look at it
tonight.
But std.datetime has a ton of unit tests and, as far as I know, is
currently passing all of them on Linux, Windows, and OS X (I don't know
about FreeBSD). The most likely problems would be on OS X or FreeBSD,
since I don't have a system with either OS X or FreeBSD, and there could
be problems in time zones other than America/Los_Angeles - particularly on
Windows where you can't easily test time zones other than the one that
you're in - since all of my development has been done in
America/Los_Angeles. But I'm not aware of any bugs. So, if you do find
problems, please report them.
Okay. This is pretty much _has_ to be either a bug in appender or in the
compiler. It happens non-derministically. The exact same program will sometimes
work just fine and sometimes the invariant will fail. It almost has to be the
case that the values being used were initialized with garbage data. It's the
kind of thing that I'd expect if = void had been used. I don't see = void in the
appender code, but it _is_ calling GC functions such as GC.extend and GC.qalloc.
I don't know enough about appender or how those functions work, but I suspect
that something isn't being properly initialized before it's used. Open a bug
report on the issue. Someone with knowledge of appender is going to have to take
a look at it.
- Jonathan M Davis
Thanks for your answer. Indeed, the bug might concern
garbage-initialized structs during appending. It is reducible to:
---
import std.array;
struct Foo {
int a, b;
Foo opAssign(Foo rhs) {
a = rhs.a;
b = rhs.b;
return this;
}
invariant () {
assert (a <= b);
}
}
unittest {
auto app = appender!(Foo[]);
auto foo = Foo(1, 2);
app.put(foo);
}
---
It involves calling an invariant() on a struct where opAssign is
overloaded. You have filed a report concerning such a problem in issue
#5058.
