Auto merge of #22724 - Manishearth:rollup, r=alexcrichton

Seems to pass `check-stage1`, but I had to tweak some things so it's going through the test gauntlet again.

Author: bors

README.md

@@ -15,28 +15,34 @@ Read ["Installing Rust"] from [The Book].
 ## Building from Source
 
 1. Make sure you have installed the dependencies:
-    * `g++` 4.7 or `clang++` 3.x
-    * `python` 2.6 or later (but not 3.x)
-    * GNU `make` 3.81 or later
-    * `curl`
-    * `git`
+
+   * `g++` 4.7 or `clang++` 3.x
+   * `python` 2.6 or later (but not 3.x)
+   * GNU `make` 3.81 or later
+   * `curl`
+   * `git`
 
 2. Clone the [source] with `git`:
 
-        $ git clone https://github.com/rust-lang/rust.git
-        $ cd rust
+   ```sh
+   $ git clone https://github.com/rust-lang/rust.git
+   $ cd rust
+   ```
 
 [source]: https://github.com/rust-lang/rust
 
 3. Build and install:
 
-        $ ./configure
-        $ make && make install
+    ```sh
+    $ ./configure
+    $ make && make install
+    ```
 
-    > ***Note:*** You may need to use `sudo make install` if you do not normally have
-    > permission to modify the destination directory. The install locations can
-    > be adjusted by passing a `--prefix` argument to `configure`. Various other
-    > options are also supported, pass `--help` for more information on them.
+    > ***Note:*** You may need to use `sudo make install` if you do not
+    > normally have permission to modify the destination directory. The
+    > install locations can be adjusted by passing a `--prefix` argument
+    > to `configure`. Various other options are also supported – pass
+    > `--help` for more information on them.
 
     When complete, `make install` will place several programs into
     `/usr/local/bin`: `rustc`, the Rust compiler, and `rustdoc`, the
@@ -47,27 +53,30 @@ Read ["Installing Rust"] from [The Book].
 
 ### Building on Windows
 
-To easily build on windows we can use [MSYS2](http://msys2.github.io/):
+[MSYS2](http://msys2.github.io/) can be used to easily build Rust on Windows:
 
 1. Grab the latest MSYS2 installer and go through the installer.
-2. Now from the MSYS2 terminal we want to install the mingw64 toolchain and the other
-   tools we need.
 
-```bash
-# choose one based on platform
-$ pacman -S mingw-w64-i686-toolchain
-$ pacman -S mingw-w64-x86_64-toolchain
+2. From the MSYS2 terminal, install the `mingw64` toolchain and other required
+   tools.
+
+   ```sh
+   # Choose one based on platform:
+   $ pacman -S mingw-w64-i686-toolchain
+   $ pacman -S mingw-w64-x86_64-toolchain
+   
+   $ pacman -S base-devel
+   ```
 
-$ pacman -S base-devel
-```
+3. Run `mingw32_shell.bat` or `mingw64_shell.bat` from wherever you installed
+   MYSY2 (i.e. `C:\msys`), depending on whether you want 32-bit or 64-bit Rust.
 
-3. With that now start `mingw32_shell.bat` or `mingw64_shell.bat`
-   from where you installed MSYS2 (i.e. `C:\msys`). Which one you
-   choose depends on if you want 32 or 64 bit Rust.
-4. From there just navigate to where you have Rust's source code, configure and build it:
+4. Navigate to Rust's source code, configure and build it:
 
-        $ ./configure
-        $ make && make install
+   ```sh
+   $ ./configure
+   $ make && make install
+   ```
 
 ## Notes
 
@@ -92,15 +101,15 @@ There is more advice about hacking on Rust in [CONTRIBUTING.md].
 
 [CONTRIBUTING.md]: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md
 
-## Getting help
+## Getting Help
 
 The Rust community congregates in a few places:
 
-* [StackOverflow] - Direct questions about using the language here.
-* [users.rust-lang.org] - General discussion, broader questions.
+* [Stack Overflow] - Direct questions about using the language.
+* [users.rust-lang.org] - General discussion and broader questions.
 * [/r/rust] - News and general discussion.
 
-[StackOverflow]: http://stackoverflow.com/questions/tagged/rust
+[Stack Overflow]: http://stackoverflow.com/questions/tagged/rust
 [/r/rust]: http://reddit.com/r/rust
 [users.rust-lang.org]: http://users.rust-lang.org/
 
@@ -111,7 +120,7 @@ To contribute to Rust, please see [CONTRIBUTING.md](CONTRIBUTING.md).
 Rust has an [IRC] culture and most real-time collaboration happens in a
 variety of channels on Mozilla's IRC network, irc.mozilla.org. The
 most popular channel is [#rust], a venue for general discussion about
-Rust, and a good place to ask for help,
+Rust, and a good place to ask for help.
 
 [IRC]: https://en.wikipedia.org/wiki/Internet_Relay_Chat
 [#rust]: irc://irc.mozilla.org/rust

src/compiletest/compiletest.rs

@@ -268,7 +268,7 @@ pub fn test_opts(config: &Config) -> test::TestOpts {
         logfile: config.logfile.clone(),
         run_tests: true,
         run_benchmarks: true,
-        nocapture: false,
+        nocapture: env::var("RUST_TEST_NOCAPTURE").is_ok(),
         color: test::AutoColor,
     }
 }

src/compiletest/header.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use std::env;
+
 use common::Config;
 use common;
 use util;
@@ -125,6 +127,16 @@ pub fn load_props(testfile: &Path) -> TestProps {
         true
     });
 
+    for key in vec!["RUST_TEST_NOCAPTURE", "RUST_TEST_TASKS"] {
+        match env::var(key) {
+            Ok(val) =>
+                if exec_env.iter().find(|&&(ref x, _)| *x == key.to_string()).is_none() {
+                    exec_env.push((key.to_string(), val))
+                },
+            Err(..) => {}
+        }
+    }
+
     TestProps {
         error_patterns: error_patterns,
         compile_flags: compile_flags,

src/compiletest/runtest.rs

@@ -89,7 +89,7 @@ fn run_cfail_test(config: &Config, props: &TestProps, testfile: &Path) {
     let proc_res = compile_test(config, props, testfile);
 
     if proc_res.status.success() {
-        fatal_proc_rec(&format!("{} test compiled successfully!", config.mode)[],
+        fatal_proc_rec(&format!("{} test compiled successfully!", config.mode)[..],
                       &proc_res);
     }
 
@@ -398,7 +398,7 @@ fn run_debuginfo_gdb_test(config: &Config, props: &TestProps, testfile: &Path) {
             for line in breakpoint_lines.iter() {
                 script_str.push_str(&format!("break {:?}:{}\n",
                                              testfile.filename_display(),
-                                             *line)[]);
+                                             *line)[..]);
             }
             script_str.push_str(&cmds);
             script_str.push_str("quit\n");
@@ -553,17 +553,17 @@ fn run_debuginfo_gdb_test(config: &Config, props: &TestProps, testfile: &Path) {
             script_str.push_str("set print pretty off\n");
 
             // Add the pretty printer directory to GDB's source-file search path
-            script_str.push_str(&format!("directory {}\n", rust_pp_module_abs_path)[]);
+            script_str.push_str(&format!("directory {}\n", rust_pp_module_abs_path)[..]);
 
             // Load the target executable
             script_str.push_str(&format!("file {}\n",
-                                         exe_file.as_str().unwrap().replace("\\", "\\\\"))[]);
+                                         exe_file.as_str().unwrap().replace("\\", "\\\\"))[..]);
 
             // Add line breakpoints
             for line in &breakpoint_lines {
                 script_str.push_str(&format!("break '{}':{}\n",
                                              testfile.filename_display(),
-                                             *line)[]);
+                                             *line)[..]);
             }
 
             script_str.push_str(&cmds);
@@ -689,7 +689,7 @@ fn run_debuginfo_lldb_test(config: &Config, props: &TestProps, testfile: &Path)
                                                .unwrap()
                                                .to_string();
 
-    script_str.push_str(&format!("command script import {}\n", &rust_pp_module_abs_path[..])[]);
+    script_str.push_str(&format!("command script import {}\n", &rust_pp_module_abs_path[..])[..]);
     script_str.push_str("type summary add --no-value ");
     script_str.push_str("--python-function lldb_rust_formatters.print_val ");
     script_str.push_str("-x \".*\" --category Rust\n");

src/doc/intro.md

@@ -426,39 +426,33 @@ use std::thread::Thread;
 fn main() {
     let mut numbers = vec![1, 2, 3];
 
-    for i in 0..3 {
-        Thread::spawn(move || {
+    let guards: Vec<_> = (0..3).map(|i| {
+        Thread::scoped(move || {
             for j in 0..3 { numbers[j] += 1 }
         });
-    }
+    }).collect();
 }
 ```
 
 It gives us this error:
 
 ```text
-6:71 error: capture of moved value: `numbers`
-    for j in 0..3 { numbers[j] += 1 }
-                    ^~~~~~~
-7:50 note: `numbers` moved into closure environment here
-    spawn(move || {
-        for j in 0..3 { numbers[j] += 1 }
-    });
-6:79 error: cannot assign to immutable dereference (dereference is implicit, due to indexing)
-        for j in 0..3 { numbers[j] += 1 }
-                        ^~~~~~~~~~~~~~~
+7:29: 9:10 error: cannot move out of captured outer variable in an `FnMut` closure
+7         Thread::scoped(move || {
+8             for j in 0..3 { numbers[j] += 1 }
+9         });
 ```
 
-It mentions that "numbers moved into closure environment". Because we
-declared the closure as a moving closure, and it referred to
-`numbers`, the closure will try to take ownership of the vector. But
-the closure itself is created in a loop, and hence we will actually
-create three closures, one for every iteration of the loop. This means
-that all three of those closures would try to own `numbers`, which is
-impossible -- `numbers` must have just one owner. Rust detects this
-and gives us the error: we claim that `numbers` has ownership, but our
-code tries to make three owners. This may cause a safety problem, so
-Rust disallows it.
+It mentions that "captured outer variable in an `FnMut` closure".
+Because we declared the closure as a moving closure, and it referred
+to `numbers`, the closure will try to take ownership of the
+vector. But the closure itself is created in a loop, and hence we will
+actually create three closures, one for every iteration of the
+loop. This means that all three of those closures would try to own
+`numbers`, which is impossible -- `numbers` must have just one
+owner. Rust detects this and gives us the error: we claim that
+`numbers` has ownership, but our code tries to make three owners. This
+may cause a safety problem, so Rust disallows it.
 
 What to do here? Rust has two types that helps us: `Arc<T>` and `Mutex<T>`.
 *Arc* stands for "atomically reference counted". In other words, an Arc will
@@ -480,14 +474,14 @@ use std::sync::{Arc,Mutex};
 fn main() {
     let numbers = Arc::new(Mutex::new(vec![1, 2, 3]));
 
-    for i in 0..3 {
+    let guards: Vec<_> = (0..3).map(|i| {
         let number = numbers.clone();
-        Thread::spawn(move || {
+        Thread::scoped(move || {
             let mut array = number.lock().unwrap();
             array[i] += 1;
             println!("numbers[{}] is {}", i, array[i]);
         });
-    }
+    }).collect();
 }
 ```
 
@@ -516,8 +510,10 @@ numbers[1] is 3
 numbers[0] is 2
 ```
 
-Each time, we get a slightly different output, because each thread works in a
-different order. You may not get the same output as this sample, even.
+Each time, we can get a slithtly different output because the threads
+are not quaranteed to run in any set order. If you get the same order
+every time it is because each of these threads are very small and
+complete too fast for their indeterminate behavior to surface.
 
 The important part here is that the Rust compiler was able to use ownership to
 give us assurance _at compile time_ that we weren't doing something incorrect
@@ -539,13 +535,13 @@ safety check that makes this an error about moved values:
 use std::thread::Thread;
 
 fn main() {
-    let vec = vec![1, 2, 3];
-
-    for i in 0..3 {
-        Thread::spawn(move || {
-            println!("{}", vec[i]);
+    let numbers = vec![1, 2, 3];
+    
+    let guards: Vec<_> = (0..3).map(|i| {
+        Thread::scoped(move || {
+            println!("{}", numbers[i]);
         });
-    }
+    }).collect();
 }
 ```
 

src/doc/reference.md

@@ -515,6 +515,9 @@ This last example is different because it is not possible to use the suffix
 syntax with a floating point literal ending in a period. `2.f64` would attempt
 to call a method named `f64` on `2`.
 
+The representation semantics of floating-point numbers are described in
+["Machine Types"](#machine-types).
+
 #### Boolean literals
 
 The two values of the boolean type are written `true` and `false`.
@@ -3554,7 +3557,8 @@ Tuple types and values are denoted by listing the types or values of their
 elements, respectively, in a parenthesized, comma-separated list.
 
 Because tuple elements don't have a name, they can only be accessed by
-pattern-matching.
+pattern-matching or by using `N` directly as a field to access the
+`N`th element.
 
 An example of a tuple type and its use:
 
@@ -3563,6 +3567,7 @@ type Pair<'a> = (i32, &'a str);
 let p: Pair<'static> = (10, "hello");
 let (a, b) = p;
 assert!(b != "world");
+assert!(p.0 == 10);
 ```
 
 ### Array, and Slice types

src/doc/trpl/crates-and-modules.md

@@ -12,7 +12,7 @@ Rust has two distinct terms that relate to the module system: *crate* and
 *module*. A crate is synonymous with a *library* or *package* in other
 languages. Hence "Cargo" as the name of Rust's package management tool: you
 ship your crates to others with Cargo. Crates can produce an executable or a
-shared library, depending on the project.
+library, depending on the project.
 
 Each crate has an implicit *root module* that contains the code for that crate.
 You can then define a tree of sub-modules under that root module. Modules allow