This fixes the bug described in issue #23150. This affected formatting any floating point number into a string in a formatting pattern that: a) required rounding up, and b) required an extra digit on the front.
So `format!(\"{:.0}\", 9.9)` would fail, but `format!(\"{:.0}\", 8.9)` would succeed. This was due to a negative integer being cast to a `usize` resulting in an 'arithmetic operation overflowed' panic.
The fix was to change the order of operations so that the number is zero before casting.
Use `discriminant_value` intrinsic for `derive(PartialOrd)`
[breaking-change]
This is a [breaking-change] because it can change the result of comparison operators when enum discriminants have been explicitly assigned. Notably in a case like:
```rust
#[derive(PartialOrd)]
enum E { A = 2, B = 1}
```
Under the old deriving, `A < B` held, because `A` came before `B` in the order of declaration. But now we use the ordering according to the provided values, and thus `A > B`. (However, this change is very unlikely to break much, if any, code, since the orderings themselves should all remain well-defined, total, etc.)
Fix#15523
The meaning of each variant of this enum was somewhat ambiguous and it's uncler
that we wouldn't even want to add more enumeration values in the future. As a
result this error has been altered to instead become an opaque structure.
Learning about the "first invalid byte index" is still an unstable feature, but
the type itself is now stable.
This commit series starts out with more official test harness support for rustdoc tests, and then each commit afterwards adds a test (where appropriate). Each commit should also test and finish independently of all others (they're all pretty separable).
I've uploaded a [copy of the documentation](http://people.mozilla.org/~acrichton/doc/std/) generated after all these commits were applied, and a double check on issues being closed would be greatly appreciated! I'll also browse the docs a bit and make sure nothing regressed too horribly.
Implements an intrinsic for extracting the value of the discriminant
enum variant values. For non-enum types, this returns zero, otherwise it
returns the value we use for discriminant comparisons. This means that
enum types that do not have a discriminant will also work in this
arrangement.
This is (at least part of) the work on Issue #24263
The main change in this patch is removing the use of `Option` inside the
inner loops of those functions to avoid comparisons where one branch
will only trigger on the first pass through the loop.
The included benchmarks go from:
test bench_max ... bench: 372 ns/iter (+/- 118)
test bench_max_by ... bench: 428 ns/iter (+/- 33)
test bench_max_by2 ... bench: 7128 ns/iter (+/- 326)
to:
test bench_max ... bench: 317 ns/iter (+/- 64)
test bench_max_by ... bench: 356 ns/iter (+/- 270)
test bench_max_by2 ... bench: 1387 ns/iter (+/- 183)
Problem noticed in http://www.reddit.com/r/rust/comments/31syce/using_iterators_to_find_the_index_of_the_min_or/
The main change in this patch is removing the use of `Option` inside the
inner loops of those functions to avoid comparisons where one branch
will only trigger on the first pass through the loop.
The included benchmarks go from:
test bench_max ... bench: 372 ns/iter (+/- 118)
test bench_max_by ... bench: 428 ns/iter (+/- 33)
test bench_max_by2 ... bench: 7128 ns/iter (+/- 326)
to:
test bench_max ... bench: 317 ns/iter (+/- 64)
test bench_max_by ... bench: 356 ns/iter (+/- 270)
test bench_max_by2 ... bench: 1387 ns/iter (+/- 183)
Problem noticed in http://www.reddit.com/r/rust/comments/31syce/using_iterators_to_find_the_index_of_the_min_or/
This method hasn't really changed since is inception, and it can often be a
nice performance win for some situations. This method also imposes no burden on
implementors or users of `Clone` as it's just a default method on the side.
This commit changes `Iterator`'s API by:
* Generalizing bounds from `Iterator` to `IntoIterator` whenever
possible, matching the semantics and ergonomics of `for` loops.
* Tightens up a few method-level bounds so that you get an error
earlier. For example, `rev` did not require `DoubleEndedIterator` even
though the result is only an `Iterator` when the original iterator was
double-ended.
Closes#23587
The bound-tightening is technically a:
[breaking-change]
but no code should break in practice.
We only implemented Clone on `extern "Rust" fn`s (for up to 8
parameters). This didn't cover `extern "C"` or `unsafe` (or
`unsafe extern "C"`) `fn`s, but there's no reason why they shouldn't be
cloneable as well.
The new impls are marked unstable because the existing impl for `extern
"Rust" fn`s is.
Fixes#24161.
This method hasn't really changed since is inception, and it can often be a
nice performance win for some situations. This method also imposes no burden on
implementors or users of `Clone` as it's just a default method on the side.
A recent change to the implementation of range iterators meant that,
even when stepping by 1, the iterators *always* involved checked
arithmetic.
This commit reverts to the earlier behavior (while retaining the
refactoring into traits).
Fixes#24095Closes#24119
cc #24014
r? @alexcrichton
These traits are currently all just unstable parts of the facade which are
implementation details for primitives further up the facade. This may make it
more difficult to find what set of methods you get if only linking to libcore,
but for now that's also unstable behavior.
Closes#22025
A recent change to the implementation of range iterators meant that,
even when stepping by 1, the iterators *always* involved checked
arithmetic.
This commit reverts to the earlier behavior (while retaining the
refactoring into traits).
Fixes#24095
cc #24014
In addition to being nicer, this also allows you to use `sum` and `product` for
iterators yielding custom types aside from the standard integers.
Due to removing the `AdditiveIterator` and `MultiplicativeIterator` trait, this
is a breaking change.
[breaking-change]
We only implemented Clone on `extern "Rust" fn`s (for up to 8
parameters). This didn't cover `extern "C"` or `unsafe` (or `unsafe
extern "C"`) `fn`s, but there's no reason why they shouldn't be
cloneable as well.
The new impls are marked unstable because the existing impl for `extern
"Rust" fn`s is.
Fixes#24161.
* Fix broken \"module-level documentation\" link on the [`trait Any` docs](http://doc.rust-lang.org/std/any/trait.Any.html) and related broken markup on the [`std::any` docs](http://doc.rust-lang.org/std/any/index.html).
* Remove an outdated or incorrect notice in the `BufRead::lines` docs. There is no such `read_string` function, and `lines` never returns an error.
r? @steveklabnik
This adds the missing methods and turns `str::pattern` in a user facing module, as per RFC.
This also contains some big internal refactorings:
- string iterator pairs are implemented with a central macro to reduce redundancy
- Moved all tests from `coretest::str` into `collectionstest::str` and left a note to prevent the two sets of tests drifting apart further.
See https://github.com/rust-lang/rust/issues/22477
Since it doesn't utilize the parameter, it's not very idiomatic since it
could just use the `Result::or` method. So this changes the example to
utilize the parameter. As far as I can tell, all the numbers in this
example are completely arbitrary.
