Implement CharIterator as a separate struct, so that it can be .clone()'d. Fix `.char_range_at_reverse` so that it performs better, closer to the forwards version. This makes the reverse iterators and users like `.rfind()` perform better.
Before
test str::bench::char_iterator ... bench: 146 ns/iter (+/- 0)
test str::bench::char_iterator_ascii ... bench: 397 ns/iter (+/- 49)
test str::bench::char_iterator_rev ... bench: 576 ns/iter (+/- 8)
test str::bench::char_offset_iterator ... bench: 128 ns/iter (+/- 2)
test str::bench::char_offset_iterator_rev ... bench: 425 ns/iter (+/- 59)
After
test str::bench::char_iterator ... bench: 130 ns/iter (+/- 1)
test str::bench::char_iterator_ascii ... bench: 307 ns/iter (+/- 5)
test str::bench::char_iterator_rev ... bench: 185 ns/iter (+/- 8)
test str::bench::char_offset_iterator ... bench: 131 ns/iter (+/- 13)
test str::bench::char_offset_iterator_rev ... bench: 183 ns/iter (+/- 2)
To be able to use a string slice to represent the CharIterator, a function `slice_unchecked` is added, that does the same as `slice_bytes` but without any boundary checks.
It would be possible to implement CharIterator with pointer arithmetic to make it *much more efficient*, but since vec iterator is still improving, it's too early to attempt to re-implement it in other places. Hopefully CharIterator can be implemented on top of vec iterator without any unsafe code later.
Additional changes fix the documentation about null termination.
For #7083.
The metadata issue with the old version is now fixed. Ready for review.
This is also not the full solution to #7083, because this is not supported yet:
```
trait Foo : Send { }
impl <T: Send> Foo for T { }
fn foo<T: Foo>(val: T, chan: std::comm::Chan<T>) {
chan.send(val);
}
```
cc @nikomatsakis
Given that bootstrapping and running the testsuite works without
exporting discriminant values as global constants, I conclude that
they're unused and can be removed.
This adds support for performing Unicode Normalization Forms D and KD on strings.
To enable this the decomposition and canonical combining class properties are added to std::unicode.
On my system this increases libstd's size by ~250KiB.
Linux and Android share the kernel, but not the C library, so sysconf constants are different. For example, _SC_PAGESIZE is 30 on Linux, but 39 on Android.
This patch
* splits sysconf constants to sysconf module
* merges non-MIPS and MIPS sysconf constants (they are same)
* adds Android sysconf constants
This patch also lets mmap tests to pass on Android.
@thestinger and I talked about this in IRC. There are a couple of use
cases for a persistent map, but they aren't common enough to justify
inclusion in libextra and vary enough that they would require multiple
implementations anyways.
In any case, fun_treemap in its current state is basically useless.
