This results in throwing away alias analysis information, because LLVM
does *not* implement reasoning about these conversions yet.
We specialize zero-size types since a `getelementptr` offset will
return us the same pointer, making it broken as a simple counter.
This module provided adaptors for the old internal iterator protocol,
but they proved to be quite unreadable and are not generic enough to
handle borrowed pointers well.
Since Rust no longer defines an internal iteration protocol, I don't
think there's going to be any reuse via these adaptors.
Code that collects fields in struct-like patterns used to ignore
wildcard patterns like `Foo{_}`. But `enter_defaults` considered
struct-like patterns as default in order to overcome this
(accoring to my understanding of situation).
However such behaviour caused code like this:
```
enum E {
Foo{f: int},
Bar
}
let e = Bar;
match e {
Foo{f: _f} => { /* do something (1) */ }
_ => { /* do something (2) */ }
}
```
consider pattern `Foo{f: _f}` as default. That caused inproper behaviour
and even segfaults while trying to destruct `Bar` as `Foo{f: _f}`.
Issues: #5625 , #5530.
This patch fixes `collect_record_or_struct_fields` to split cases of
single wildcard struct-like pattern and no struct-like pattern at all.
Former case resolved with `enter_rec_or_struct` (and not with
`enter_defaults`).
Closes#5625.
Closes#5530.
This lazily initializes the taskgroup structs for ```spawn_unlinked``` tasks. If such a task never spawns another task linked to it (or a descendant of it), its taskgroup is simply never initialized at all. Also if an unlinked task spawns another unlinked task, neither of them will need to initialize their taskgroups. This works for the main task too.
I benchmarked this with the following test case and observed a ~~21% speedup (average over 4 runs: 7.85 sec -> 6.20 sec, 2.5 GHz)~~ 11% speedup, see comment below.
```
use std::task;
use std::cell::Cell;
use std::rt::comm;
static NUM: uint = 1024*256;
fn run(f: ~fn()) {
let mut t = task::task();
t.unlinked();
t.spawn(f);
}
fn main() {
do NUM.times {
let (p,c) = comm::oneshot();
let c = Cell::new(c);
do run { c.take().send(()); }
p.recv();
}
}
```
Encoding should really only be done from [u8]<->str. The extra
convenience implementations don't really have a place, especially since
they're so trivial.
Also improved error messages in FromBase64.
The overhead of str::push_char is high enough to cripple the performance
of these two functions. I've switched them to build the output in a
~[u8] and then convert to a string later. Since we know exactly the
bytes going into the vector, we can use the unsafe version to avoid the
is_utf8 check.
I could have riced it further with vec::raw::get, but it only added
~10MB/s so I didn't think it was worth it. ToHex is still ~30% slower
than FromHex, which is puzzling.
Before:
```
test base64::test::from_base64 ... bench: 1000 ns/iter (+/- 349) = 204 MB/s
test base64::test::to_base64 ... bench: 2390 ns/iter (+/- 1130) = 63 MB/s
...
test hex::tests::bench_from_hex ... bench: 884 ns/iter (+/- 220) = 341 MB/s
test hex::tests::bench_to_hex ... bench: 2453 ns/iter (+/- 919) = 61 MB/s
```
After:
```
test base64::test::from_base64 ... bench: 1271 ns/iter (+/- 600) = 160 MB/s
test base64::test::to_base64 ... bench: 759 ns/iter (+/- 286) = 198 MB/s
...
test hex::tests::bench_from_hex ... bench: 875 ns/iter (+/- 377) = 345 MB/s
test hex::tests::bench_to_hex ... bench: 593 ns/iter (+/- 240) = 254 MB/s
```
FromHex ignores whitespace and parses either upper or lower case hex
digits. ToHex outputs lower case hex digits with no whitespace. Unlike
ToBase64, ToHex doesn't allow you to configure the output format. I
don't feel that it's super useful in this case.
Better than that in rt::uv::net, because it:
* handles invalid input explicitly, without fail!()
* parses socket address, not just IP
* handles various ipv4-in-ipv6 addresses, like 2001:db8:122:344::192.0.2.33
(see http://tools.ietf.org/html/rfc6052 for example)
* rejects output like `127.0000000.0.1`
* does not allocate heap memory
* have unit tests
`fn slice_bytes` is marked unsafe since it allows violating the valid
string encoding property; but the function did also allow extending the
lifetime of the slice by mistake, since it's returning `&str`.
Use the annotation `slice_bytes<'a>(&'a str, ...) -> &'a str` so
that all uses of `slice_bytes` are region checked correctly.
Fix#8228 by replacing .iter() and .iter_err() in Result by external iterators.
Implement random access for `iterator::Invert` and `vec::ChunkIter` (and bidirectionality).
Implement Repeat iterator.
Let Option be a base for a widely useful one- or zero- item iterator.
Refactor OptionIterator to support any generic element type, so the same
iterator impl can be used for both &T, &mut T and T iterators.
