… congruent due to rounding errors
@semarie this affected both openbsd and bitrig. it seems the correct solution is to switch to fixed point arithmetic in the timeout code, the same as freebsd.
Various methods in both libcore/char.rs and librustc_unicode/char.rs were previously marked with #[inline], now every method is marked in char's impl blocks.
Partially fixes#26124.
EDIT: I'm not familiar with pull reqests (yet), apparently Github added my second commit to thit PR...
Fixes#26124
Implement RFC rust-lang/rfcs#1123
Add str method str::split_at(mid: usize) -> (&str, &str).
Also a minor cleanup in the collections::str module. Remove redundant slicing of self.
As far as I was able to determine, it's currently *impossible* to allocate a C NUL-terminated string in Rust and then return it to C (transferring ownership), without leaking memory. There is support for passing the string to C (borrowing).
To complicate matters, it's not possible for the C code to just call `free` on the allocated string, due to the different allocators in use.
`CString` has no way to recreate itself from a pointer. This commit adds one. This is complicated a bit because Rust `Vec`s want the pointer, size, and capacity.
To deal with that, another method to shrink and "leak" the `CString` to a `char *` is also provided.
We can then use `strlen` to determine the length of the string, which must match the capacity.
**TODO**
- [x] Improve documentation
- [x] Add stability markers
- [x] Convert to `Box<[u8]>`
### Example code
With this example code:
```rust
#![feature(libc)]
#![feature(cstr_to_str)]
#![feature(c_str_memory)]
extern crate libc;
use std::ffi::{CStr,CString};
#[no_mangle]
pub extern fn reverse(s: *const libc::c_char) -> *const libc::c_char {
let s = unsafe { CStr::from_ptr(s) };
let s2 = s.to_str().unwrap();
let s3: String = s2.chars().rev().collect();
let s4 = CString::new(s3).unwrap();
s4.into_ptr()
}
#[no_mangle]
pub extern fn cleanup(s: *const libc::c_char) {
unsafe { CString::from_ptr(s) };
}
```
Compiled using `rustc --crate-type dylib str.rs`, I was able to link against it from C (`gcc -L. -l str str.c -o str`):
```c
#include <stdio.h>
extern char *reverse(char *);
extern void cleanup(char *);
int main() {
char *s = reverse("Hello, world!");
printf("%s\n", s);
cleanup(s);
}
```
As well as dynamically link via Ruby:
```ruby
require 'fiddle'
require 'fiddle/import'
module LibSum
extend Fiddle::Importer
dlload './libstr.dylib'
extern 'char* reverse(char *)'
extern 'void cleanup(char *)'
end
s = LibSum.reverse("hello, world!")
puts s
LibSum.cleanup(s)
```
Doc patch for #26120. Extra words here, because "value" is repeated.
I haven't read about whether/how it should go to stable (sorry), but I think it would help newcomers.
Thanks,
* Slate these features to be stable in 1.2 instead of 1.1 (not being backported)
* Have the `FromRawFd` implementations follow the contract of the `FromRawFd`
trait by taking ownership of the primitive specified.
* Refactor the implementations slightly to remove the `unreachable!` blocks as
well as separating the stdio representation of `std::process` from
`std::sys::process`.
This commit stabilizes the following APIs, slating them all to be cherry-picked
into the 1.1 release.
* fs::FileType (and transitively the derived trait implementations)
* fs::Metadata::file_type
* fs::FileType::is_dir
* fs::FileType::is_file
* fs::FileType::is_symlink
* fs::DirEntry::metadata
* fs::DirEntry::file_type
* fs::DirEntry::file_name
* fs::set_permissions
* fs::symlink_metadata
* os::raw::{self, *}
* os::{android, bitrig, linux, ...}::raw::{self, *}
* os::{android, bitrig, linux, ...}::fs::MetadataExt
* os::{android, bitrig, linux, ...}::fs::MetadataExt::as_raw_stat
* os::unix::fs::PermissionsExt
* os::unix::fs::PermissionsExt::mode
* os::unix::fs::PermissionsExt::set_mode
* os::unix::fs::PermissionsExt::from_mode
* os::unix::fs::OpenOptionsExt
* os::unix::fs::OpenOptionsExt::mode
* os::unix::fs::DirEntryExt
* os::unix::fs::DirEntryExt::ino
* os::windows::fs::MetadataExt
* os::windows::fs::MetadataExt::file_attributes
* os::windows::fs::MetadataExt::creation_time
* os::windows::fs::MetadataExt::last_access_time
* os::windows::fs::MetadataExt::last_write_time
* os::windows::fs::MetadataExt::file_size
The `os::unix::fs::Metadata` structure was also removed entirely, moving all of
its associated methods into the `os::unix::fs::MetadataExt` trait instead. The
methods are all marked as `#[stable]` still.
As some minor cleanup, some deprecated and unstable fs apis were also removed:
* File::path
* Metadata::accessed
* Metadata::modified
Features that were explicitly left unstable include:
* fs::WalkDir - the semantics of this were not considered in the recent fs
expansion RFC.
* fs::DirBuilder - it's still not 100% clear if the naming is right here and if
the set of functionality exposed is appropriate.
* fs::canonicalize - the implementation on Windows here is specifically in
question as it always returns a verbatim path. Additionally the Unix
implementation is susceptible to buffer overflows on long paths unfortunately.
* fs::PathExt - as this is just a convenience trait, it is not stabilized at
this time.
* fs::set_file_times - this funciton is still waiting on a time abstraction.
