0201334439
closes #19141 closes #20193 closes #20228 --- Currently whenever we encounter `let f = || {/* */}`, we *always* type check the RHS as a *boxed* closure. This is wrong when the RHS is `move || {/* */}` (because boxed closures can't capture by value) and generates all sort of badness during trans (see issues above). What we *should* do is always type check `move || {/* */}` as an *unboxed* closure, but ~~I *think* (haven't tried)~~ (2) this is not feasible right now because we have a limited form of kind (`Fn` vs `FnMut` vs `FnOnce`) inference that only works when there is an expected type (1). In this PR, I've chosen to generate a type error whenever `let f = move || {/* */}` is encountered. The error asks the user to annotate the kind of the unboxed closure (e.g. `move |:| {/* */}`). Once annotated, the compiler will type check the RHS as an unboxed closure which is what the user wants. r? @nikomatsakis (1) AIUI it only triggers in this scenario: ``` rust fn is_uc<F>(_: F) where F: FnOnce() {} fn main() { is_uc(|| {}); // type checked as unboxed closure with kind `FnOnce` } ``` (2) I checked, and it's not possible because `check_unboxed_closure` expects a `kind` argument, but we can't supply that argument in this case (i.e. `let f = || {}`, what's the kind?). We could force the `FnOnce` kind in that case, but that's ad hoc. We should try to infer the kind depending on how the closure is used afterwards, but there is no inference mechanism to do that (at least, not right now). |
||
|---|---|---|
| man | ||
| mk | ||
| src | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .mailmap | ||
| .travis.yml | ||
| AUTHORS.txt | ||
| configure | ||
| CONTRIBUTING.md | ||
| COPYRIGHT | ||
| LICENSE-APACHE | ||
| LICENSE-MIT | ||
| Makefile.in | ||
| README.md | ||
| RELEASES.md | ||
The Rust Programming Language
This is a compiler for Rust, including standard libraries, tools and documentation.
Quick Start
- Download a binary installer for your platform.
- Read the guide.
- Enjoy!
Note: Windows users can read the detailed using Rust on Windows notes on the wiki.
Building from Source
-
Make sure you have installed the dependencies:
g++4.7 orclang++3.xpython2.6 or later (but not 3.x)perl5.0 or later- GNU
make3.81 or later curlgit
-
Download and build Rust:
You can either download a tarball or build directly from the repo.
To build from the tarball do:
$ curl -O https://static.rust-lang.org/dist/rust-nightly.tar.gz $ tar -xzf rust-nightly.tar.gz $ cd rust-nightlyOr to build from the repo do:
$ git clone https://github.com/rust-lang/rust.git $ cd rustNow that you have Rust's source code, you can configure and build it:
$ ./configure $ make && make installNote: You may need to use
sudo make installif you do not normally have permission to modify the destination directory. The install locations can be adjusted by passing a--prefixargument toconfigure. Various other options are also supported, pass--helpfor more information on them.When complete,
make installwill place several programs into/usr/local/bin:rustc, the Rust compiler, andrustdoc, the API-documentation tool. -
Read the guide.
-
Enjoy!
Building on Windows
To easily build on windows we can use MSYS2:
-
Grab the latest MSYS2 installer and go through the installer.
-
Now from the MSYS2 terminal we want to install the mingw64 toolchain and the other tools we need.
$ pacman -S mingw-w64-i686-toolchain $ pacman -S base-devel -
With that now start
mingw32_shell.batfrom where you installed MSYS2 (i.e.C:\msys). -
From there just navigate to where you have Rust's source code, configure and build it:
$ ./configure $ make && make install
Notes
Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier state of development). As such, source builds require a connection to the Internet, to fetch snapshots, and an OS that can execute the available snapshot binaries.
Snapshot binaries are currently built and tested on several platforms:
- Windows (7, 8, Server 2008 R2), x86 and x86-64 (64-bit support added in Rust 0.12.0)
- Linux (2.6.18 or later, various distributions), x86 and x86-64
- OSX 10.7 (Lion) or greater, x86 and x86-64
You may find that other platforms work, but these are our officially supported build environments that are most likely to work.
Rust currently needs about 1.5 GiB of RAM to build without swapping; if it hits swap, it will take a very long time to build.
There is a lot more documentation in the wiki.
Getting help and getting involved
The Rust community congregates in a few places:
- StackOverflow - Get help here.
- /r/rust - General discussion.
- discuss.rust-lang.org - For development of the Rust language itself.
License
Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.