Changed 0 into '0'
Right now `0` is an undefined production rule.
[Documentation following the grammar specification](https://doc.rust-lang.org/nightly/std/fmt/#sign0) strongly suggests `'0'` is meant as it is used as a character literal.
r? @steveklabnik
Add method str::repeat(self, usize) -> String
It is relatively simple to repeat a string n times:
`(0..n).map(|_| s).collect::<String>()`. It becomes slightly more
complicated to do it “right” (sizing the allocation up front), which
warrants a method that does it for us.
This method is useful in writing testcases, or when generating text.
`format!()` can be used to repeat single characters, but not repeating
strings like this.
It is relatively simple to repeat a string n times:
`(0..n).map(|_| s).collect::<String>()`. It becomes slightly more
complicated to do it “right” (sizing the allocation up front), which
warrants a method that does it for us.
This method is useful in writing testcases, or when generating text.
`format!()` can be used to repeat single characters, but not repeating
strings like this.
std: Stabilize and deprecate APIs for 1.13
This commit is intended to be backported to the 1.13 branch, and works with the
following APIs:
Stabilized
* `i32::checked_abs`
* `i32::wrapping_abs`
* `i32::overflowing_abs`
* `RefCell::try_borrow`
* `RefCell::try_borrow_mut`
Deprecated
* `BinaryHeap::push_pop`
* `BinaryHeap::replace`
* `SipHash13`
* `SipHash24`
* `SipHasher` - use `DefaultHasher` instead in the `std::collections::hash_map`
module
Closes#28147Closes#34767Closes#35057Closes#35070
This commit is intended to be backported to the 1.13 branch, and works with the
following APIs:
Stabilized
* `i32::checked_abs`
* `i32::wrapping_abs`
* `i32::overflowing_abs`
* `RefCell::try_borrow`
* `RefCell::try_borrow_mut`
* `DefaultHasher`
* `DefaultHasher::new`
* `DefaultHasher::default`
Deprecated
* `BinaryHeap::push_pop`
* `BinaryHeap::replace`
* `SipHash13`
* `SipHash24`
* `SipHasher` - use `DefaultHasher` instead in the `std::collections::hash_map`
module
Closes#28147Closes#34767Closes#35057Closes#35070
Working asmjs and wasm targets
This patch set results in a working standard library for the asmjs-unknown-emscripten and wasm32-unknown-emscripten targets. It is based on the work of @badboy and @rschulman.
It does a few things:
- Updates LLVM with the emscripten [fastcomp](https://github.com/rust-lang/llvm/pull/50) patches, which include the pnacl IR legalizer and the asm.js backend. This patch is thought not to have any significant effect on existing targets.
- Teaches rustbuild to correctly link C code with emscripten
- Updates gcc-rs to work correctly with emscripten
- Teaches rustbuild to run crate tests for emscripten with node
- Modifies Thread::new to return an error on emscripten, to facilitate debugging a common failure mode
- Modifies libtest to run in single-threaded mode for emscripten
- Ignores a host of tests that don't work yet, mostly dealing with threads and I/O
- Updates libc with wasm32 definitions (presently the same as asmjs)
- Adds a wasm32-unknown-emscripten target that feeds the output of LLVM's asmjs backend through emcc to generate wasm
Notes and caveats:
- This is only known to work with `--enable-rustbuild`.
- The wasm32 target can't be tested correctly yet because of issues in compiletest and limitations in node https://github.com/kripken/emscripten/issues/4542, but hello.rs does seem to work when run on node via the binaryen interpreter
- This requires an up to date installation of the emscripten sdk from its incoming branch
- Unwinding is very broken
- When enabling the emscripten targets jemalloc is disabled for all targets, which results in test failures for the host
Next steps are to fix the jemalloc issue, start building the two emscripten targets on the auto builders, then start producing nightlies.
https://github.com/rust-lang/rust/issues/36317 tracks work on this.
Fixes https://github.com/rust-lang/rust/issues/36515
Fixes https://github.com/rust-lang/rust/issues/36515
Fixes https://github.com/rust-lang/rust/issues/36356
Change encode_utf{8,16}() to write to a buffer and panic if it's too small
cc #27784
Should the "A buffer that's too small" examples be removed and replaced by tests?
This does not actually add anything that wasn't there, but is merely an
optimization for the given cases, which would have incurred additional
heap allocation for adding empty strings, and improving the ergonomics
of `Cow` with strings.
Documentation of what Default does for each type
Addresses #36265
I haven't changed the following types due to doubts:
1)src/libstd/ffi/c_str.rs
2)src/libcore/iter/sources.rs
3)src/libcore/hash/mod.rs
4)src/libcore/hash/mod.rs
5)src/librustc/middle/privacy.rs
r? @steveklabnik
Due to missing noalias annotations for &mut T in general (issue #31681),
in larger programs extend_from_slice and extend_with_element may both
compile very poorly. What is observed is that the .set_len() calls are
not lifted out of the loop, even for `Vec<u8>`.
Use a local length variable for the Vec length instead, and use a scope
guard to write this value back to self.len when the scope ends or on
panic. Then the alias analysis is easy.
This affects extend_from_slice, extend_with_element, the vec![x; n]
macro, Write impls for Vec<u8>, BufWriter, etc (but may / may not
have triggered since inlining can be enough for the compiler to get it right).
Implement 1581 (FusedIterator)
* [ ] Implement on patterns. See https://github.com/rust-lang/rust/issues/27721#issuecomment-239638642.
* [ ] Handle OS Iterators. A bunch of iterators (`Args`, `Env`, etc.) in libstd wrap platform specific iterators. The current ones all appear to be well-behaved but can we assume that future ones will be?
* [ ] Does someone want to audit this? On first glance, all of the iterators on which I implemented `FusedIterator` appear to be well-behaved but there are a *lot* of them so a second pair of eyes would be nice.
* I haven't touched rustc internal iterators (or the internal rand) because rustc doesn't actually call `fuse()`.
* `FusedIterator` can't be implemented on `std::io::{Bytes, Chars}`.
Closes: #35602 (Tracking Issue)
Implements: rust-lang/rfcs#1581
