The old `Bitv` structure had two variations: one represented by a vector of
uints, and another represented by a single uint for bit vectors containing
fewer than uint::BITS bits.
The purpose of this is to avoid the indirection of using a Vec, but the
speedup is only available to users who
(a) are storing less than uints::BITS bits
(b) know this when they create the vector (since `Bitv`s cannot be resized)
(c) don't know this at compile time (else they could use uint directly)
Giving such specific users a (questionable) speed benefit at the cost of
adding explicit checks to almost every single bit call, frequently writing
the same method twice and making iteration much much more difficult, does
not seem like a worthwhile tradeoff to me.
Also, rustc does not use Bitv anywhere, only through BitvSet, which does
not have this optimization.
For reference, here is some speed data from before and after this PR:
BEFORE:
test bitv::tests::bench_bitv_big ... bench: 4 ns/iter (+/- 1)
test bitv::tests::bench_bitv_big_iter ... bench: 4858 ns/iter (+/- 22)
test bitv::tests::bench_bitv_big_union ... bench: 507 ns/iter (+/- 35)
test bitv::tests::bench_bitv_set_big ... bench: 6 ns/iter (+/- 1)
test bitv::tests::bench_bitv_set_small ... bench: 6 ns/iter (+/- 0)
test bitv::tests::bench_bitv_small ... bench: 5 ns/iter (+/- 1)
test bitv::tests::bench_bitvset_iter ... bench: 12930 ns/iter (+/- 662)
test bitv::tests::bench_btv_small_iter ... bench: 39 ns/iter (+/- 1)
test bitv::tests::bench_uint_small ... bench: 4 ns/iter (+/- 1)
AFTER:
test bitv::tests::bench_bitv_big ... bench: 5 ns/iter (+/- 1)
test bitv::tests::bench_bitv_big_iter ... bench: 5004 ns/iter (+/- 102)
test bitv::tests::bench_bitv_big_union ... bench: 356 ns/iter (+/- 26)
test bitv::tests::bench_bitv_set_big ... bench: 6 ns/iter (+/- 0)
test bitv::tests::bench_bitv_set_small ... bench: 6 ns/iter (+/- 1)
test bitv::tests::bench_bitv_small ... bench: 4 ns/iter (+/- 1)
test bitv::tests::bench_bitvset_iter ... bench: 12918 ns/iter (+/- 621)
test bitv::tests::bench_btv_small_iter ... bench: 50 ns/iter (+/- 5)
test bitv::tests::bench_uint_small ... bench: 4 ns/iter (+/- 1)
Slice patterns are different from the rest in that a single slice pattern
does not have a distinct constructor if it contains a variable-length subslice
pattern. For example, the pattern [a, b, ..tail] can match a slice of length 2, 3, 4
and so on.
As a result, the decision tree for exhaustiveness and redundancy analysis should
explore each of those constructors separately to determine if the pattern could be useful
when specialized for any of them.
* channel() - #[unstable]. This will likely remain forever
* sync_channel(n: int) - #[unstable with comment]. Concerns have ben raised
about the usage of the term "synchronous channel" because that generally only
applies to the case where n == 0. If n > 0 then these channels are often
referred to as buffered channels.
* Sender::send(), SyncSender::send(), Receiver::recv() - #[experimental]. These
functions directly violate the general guideline of not providing a failing
and non-failing variant. These functions were explicitly selected for being
excused from this guideline, but recent discussions have cast doubt on that
decision. These functions are #[experimental] for now until a decision is made
as they are candidates for removal.
* Sender::send_opt(), SyncSender::send_opt(), Receiver::recv_opt() - #[unstable
with a comment]. If the above no-`_opt` functions are removed, these functions
will be renamed to the non-`_opt` variants.
* SyncSender::try_send(), Receiver::try_recv() - #[unstable with a comment].
These return types of these functions to not follow general conventions. They
are consistent with the rest of the api, but not with the rest of the
libraries. Until their return types are nailed down, these functions are
#[unstable].
* Receiver::iter() - #[unstable]. This will likely remain forever.
* std::com::select - #[experimental]. The functionality is likely to remain in
some form forever, but it is highly unlikely to remain in its current form. It
is unknown how much breakage this will cause if and when the api is
redesigned, so the entire module and its components are all experimental.
* DuplexStream - #[deprecated]. This type is not composable with other channels
in terms of selection or other expected locations. It can also not be used
with ChanWriter and ChanReader, for example. Due to it being only lightly
used, and easily replaced with two channels, this type is being deprecated and
slated for removal.
* Clone for {,Sync}Sender - #[unstable]. This will likely remain forever.
* channel() - #[unstable]. This will likely remain forever
* sync_channel(n: int) - #[unstable with comment]. Concerns have ben raised
about the usage of the term "synchronous channel" because that generally only
applies to the case where n == 0. If n > 0 then these channels are often
referred to as buffered channels.
* Sender::send(), SyncSender::send(), Receiver::recv() - #[experimental]. These
functions directly violate the general guideline of not providing a failing
and non-failing variant. These functions were explicitly selected for being
excused from this guideline, but recent discussions have cast doubt on that
decision. These functions are #[experimental] for now until a decision is made
as they are candidates for removal.
* Sender::send_opt(), SyncSender::send_opt(), Receiver::recv_opt() - #[unstable
with a comment]. If the above no-`_opt` functions are removed, these functions
will be renamed to the non-`_opt` variants.
* SyncSender::try_send(), Receiver::try_recv() - #[unstable with a comment].
These return types of these functions to not follow general conventions. They
are consistent with the rest of the api, but not with the rest of the
libraries. Until their return types are nailed down, these functions are
#[unstable].
* Receiver::iter() - #[unstable]. This will likely remain forever.
* std::com::select - #[experimental]. The functionality is likely to remain in
some form forever, but it is highly unlikely to remain in its current form. It
is unknown how much breakage this will cause if and when the api is
redesigned, so the entire module and its components are all experimental.
* DuplexStream - #[deprecated]. This type is not composable with other channels
in terms of selection or other expected locations. It can also not be used
with ChanWriter and ChanReader, for example. Due to it being only lightly
used, and easily replaced with two channels, this type is being deprecated and
slated for removal.
* Clone for {,Sync}Sender - #[unstable]. This will likely remain forever.
So far, type names generated for debuginfo where a bit sketchy. It was not clearly defined when a name should be fully qualified and when not, if region parameters should be shown or not, and other things like that.
This commit makes the debuginfo module responsible for creating type names instead of using ppaux::ty_to_str() and brings type names, as they show up in the DWARF information, in line with GCC and Clang:
* The name of the type being described is unqualified. It's path is defined by its position in the namespace hierarchy.
* Type arguments are always fully qualified, no matter if they would actually be in scope at the type definition location.
Care is also taken to reliably make type names consistent across crate boundaries. That is, the code now tries make the type name the same, regardless if the type is in the local crate or reconstructed from metadata. Otherwise LLVM will complain about violating the one-definition-rule when using link-time-optimization.
This commit also removes all source location information from type descriptions because these cannot be reconstructed for types instantiated from metadata. Again, with LTO enabled, this can lead to two versions of the debuginfo type description, one with and one without source location information, which then triggers the LLVM ODR assertion.
Fortunately, source location information about types is rarely used, so this has little impact. Once source location information is preserved in metadata (#1972) it can also be reenabled for type descriptions.
POSIX has recvfrom(2) and sendto(2), but their name seem not to be suitable with Rust. We already renamed getpeername(2) and getsockname(2), so I think it makes sense.
Alternatively, `receive_from` would be fine. However, we have `.recv()` so I chose `recv_from`.
What do you think? If this makes sense, should I provide `recvfrom` and `sendto` deprecated methods just calling new methods for compatibility?
While `HashMap::new` and `HashMap::with_capacity` were being initialized with a random `SipHasher`, it turns out that `HashMap::from_iter` was just using the default instance of `SipHasher`, which wasn't randomized. This closes that bug, and also inlines some important methods.
Being able to index into the bytes of a string encourages
poor UTF-8 hygiene. To get a view of `&[u8]` from either
a `String` or `&str` slice, use the `as_bytes()` method.
Closes#12710.
[breaking-change]
If the diffstat is any indication this shouldn't have a huge impact but it will have some. Most changes in the `str` and `path` module. A lot of the existing usages were in tests where ascii is expected. There are a number of other legit uses where the characters are known to be ascii.
with the corresponding trait parameter bounds.
This is a version of the patch in PR #12611 by Florian Hahn, modified to
address Niko's feedback.
It does not address the issue of duplicate type parameter bounds, nor
does it address the issue of implementation-defined methods that contain
*fewer* bounds than the trait, because Niko's review indicates that this
should not be necessary (and indeed I believe it is not). A test has
been added to ensure that this works.
This will break code like:
trait Foo {
fn bar<T:Baz>();
}
impl Foo for Boo {
fn bar<T:Baz + Quux>() { ... }
// ^~~~ ERROR
}
This will be rejected because the implementation requires *more* bounds
than the trait. It can be fixed by either adding the missing bound to
the trait:
trait Foo {
fn bar<T:Baz + Quux>();
// ^~~~
}
impl Foo for Boo {
fn bar<T:Baz + Quux>() { ... } // OK
}
Or by removing the bound from the impl:
trait Foo {
fn bar<T:Baz>();
}
impl Foo for Boo {
fn bar<T:Baz>() { ... } // OK
// ^ remove Quux
}
This patch imports the relevant tests from #2687, as well as the test
case in #5886, which is fixed as well by this patch.
Closes#2687.
Closes#5886.
[breaking-change]
It's looking like we're still timing out all over the place with travis_wait
because the entire `make -j4 rustc-stage1` command is taking too long. Instead,
achieve roughly the same idea by just having `-Z time-passes` printing
information. We shouldn't have a pass that takes longer than 10 minutes in
isolation.
Being able to index into the bytes of a string encourages
poor UTF-8 hygiene. To get a view of `&[u8]` from either
a `String` or `&str` slice, use the `as_bytes()` method.
Closes#12710.
[breaking-change]
Whew. So much here! Feedback very welcome.
This is the first part where we actually start learning things. I'd like to think I struck a good balance of explaining enough details, without getting too bogged down, and without being confusing... but of course I'd think that. 😉
As I mention in the commit comment, We probably want to move the guessing game to the rust-lang org, rather than just having it on my GitHub. Or, I could put the code inline. I think it'd be neat to have it as a project, so people can pull it down with Cargo. Until we make that decision, I'll just leave this here.
Whew! Who knew there was so much to say about variables.
We probably want to move the guessing game to the rust-lang org, rather than
just having it on my GitHub. Or, I could put the code inline. I think it'd be
neat to have it as a project, so people can pull it down with Cargo. Until we
make that decision, I'll just leave this here.
Part of #14248
Main authors:
- @Ryman: OK
- @TeXitoi: OK
- @pcwalton: OK
Minor authors:
- @brson: OK
- @alexcrichton: OK
- @kballard: OK
Remark: @tedhorst was a main contributor, but its contribution
disapear with @pcwalton rewrite at af4ea11
@brson OK?
POSIX has recvfrom(2) and sendto(2), but their name seem not to be
suitable with Rust. We already renamed getpeername(2) and
getsockname(2), so I think it makes sense.
Alternatively, `receive_from` would be fine. However, we have `.recv()`
so I chose `recv_from`.
Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
- Fix a couple mistakes:
- `Ordering` is an enum, not a trait.
- `Container` is now named `Collection`.
- Add missing `CheckedDiv`.
- Remove obsolete `OwnedVector`.
- Reorganize some lines to match [prelude's arrangement](http://doc.rust-lang.org/std/prelude/#reexports), making mistakes easier to spot in the future.
I'm going to move testing to be right AFTER the guessing game. I wanted it
to be borderline TDD, but I think that, since the first example is just one
file, it might be a bit overkill.
I'm doing this in its own commit to hopefully avoid merge conflicts.
Earlier commits have established a baseline of `experimental` stability
for all crates under the facade (so their contents are considered
experimental within libstd). Since `experimental` is `allow` by
default, we should use the same baseline stability for libstd itself.
This commit adds `experimental` tags to all of the modules defined in
`std`, and `unstable` to `std` itself.
This does two things:
* Reorganizes the declaration order to be more readable, less random.
* Removes the `slice::traits` module, a public module that does nothing but declare impls of `cmp` traits.
Part of #14248
Main authors:
- @Ryman: OK
- @TeXitoi: OK
- @pcwalton: OK
Minor authors:
- @brson: OK
- @alexcrichton: OK
- @kballard: OK
Remark: @tedhorst was a main contributor, but its contribution
disapear with @pcwalton rewrite at af4ea11
This commit hooks rustdoc into the stability index infrastructure in two
ways:
1. It looks up stability levels via the index, rather than by manual
attributes.
2. It adds stability level information throughout rustdoc output, rather
than just at the top header. In particular, a stability color (with
mouseover text) appears next to essentially every item that appears
in rustdoc's HTML output.
Along the way, the stability index code has been lightly refactored.
Earlier commits have established a baseline of `experimental` stability
for all crates under the facade (so their contents are considered
experimental within libstd). Since `experimental` is `allow` by
default, we should use the same baseline stability for libstd itself.
This commit adds `experimental` tags to all of the modules defined in
`std`, and `unstable` to `std` itself.
This commit hooks rustdoc into the stability index infrastructure in two
ways:
1. It looks up stability levels via the index, rather than by manual
attributes.
2. It adds stability level information throughout rustdoc output, rather
than just at the top header. In particular, a stability color (with
mouseover text) appears next to essentially every item that appears
in rustdoc's HTML output.
Along the way, the stability index code has been lightly refactored.
I'm working on adding examples to the API documentation. Should future pull requests include examples for more than one function? Or is this about the right size for a pull request?
./hello_world is not recognized on Windows.
We can type either hello_world or hello_world.exe to run the executable. I chose "hello_world.exe", which seems more conventional on Windows.
