Merge remote-tracking branch 'origin/master' into proc_macro_api

6 files changed, 49 insertions, 54 deletions

diff --git a/src/doc/unstable-book/src/language-features/compile-error.md b/src/doc/unstable-book/src/language-features/compile-error.md
index 1b25eeda3f6..4b24c0a6a0d 100644
--- a/src/doc/unstable-book/src/language-features/compile-error.md
+++ b/src/doc/unstable-book/src/language-features/compile-error.md
@@ -2,7 +2,7 @@
 
 The tracking issue for this feature is: [#40872]
 
-[#29599]: https://github.com/rust-lang/rust/issues/40872
+[#40872]: https://github.com/rust-lang/rust/issues/40872
 
 ------------------------
 
diff --git a/src/doc/unstable-book/src/language-features/lang-items.md b/src/doc/unstable-book/src/language-features/lang-items.md
index 375b8bd6b82..a2368ee5f4a 100644
--- a/src/doc/unstable-book/src/language-features/lang-items.md
+++ b/src/doc/unstable-book/src/language-features/lang-items.md
@@ -143,7 +143,8 @@ pub extern fn rust_eh_unwind_resume() {
 #[no_mangle]
 pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
                                _file: &'static str,
-                               _line: u32) -> ! {
+                               _line: u32,
+                               _column: u32) -> ! {
     unsafe { intrinsics::abort() }
 }
 ```
@@ -187,7 +188,8 @@ pub extern fn rust_eh_unwind_resume() {
 #[no_mangle]
 pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
                                _file: &'static str,
-                               _line: u32) -> ! {
+                               _line: u32,
+                               _column: u32) -> ! {
     unsafe { intrinsics::abort() }
 }
 ```
diff --git a/src/doc/unstable-book/src/language-features/unsized-tuple-coercion.md b/src/doc/unstable-book/src/language-features/unsized-tuple-coercion.md
new file mode 100644
index 00000000000..200a9c19462
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/unsized-tuple-coercion.md
@@ -0,0 +1,27 @@
+# `unsized_tuple_coercion`
+
+The tracking issue for this feature is: [#42877]
+
+[#42877]: https://github.com/rust-lang/rust/issues/42877
+
+------------------------
+
+This is a part of [RFC0401]. According to the RFC, there should be an implementation like this:
+
+```rust
+impl<..., T, U: ?Sized> Unsized<(..., U)> for (..., T) where T: Unsized<U> {}
+```
+
+This implementation is currently gated behind `#[feature(unsized_tuple_coercion)]` to avoid insta-stability. Therefore you can use it like this:
+
+```rust
+#![feature(unsized_tuple_coercion)]
+
+fn main() {
+    let x : ([i32; 3], [i32; 3]) = ([1, 2, 3], [4, 5, 6]);
+    let y : &([i32; 3], [i32]) = &x;
+    assert_eq!(y.1[0], 4);
+}
+```
+
+[RFC0401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md
diff --git a/src/doc/unstable-book/src/library-features/iterator-for-each.md b/src/doc/unstable-book/src/library-features/iterator-for-each.md
new file mode 100644
index 00000000000..ebeb5f6a1de
--- /dev/null
+++ b/src/doc/unstable-book/src/library-features/iterator-for-each.md
@@ -0,0 +1,17 @@
+# `iterator_for_each`
+
+The tracking issue for this feature is: [#42986]
+
+[#42986]: https://github.com/rust-lang/rust/issues/42986
+
+------------------------
+
+To call a closure on each element of an iterator, you can use `for_each`:
+
+```rust
+#![feature(iterator_for_each)]
+
+fn main() {
+    (0..10).for_each(|i| println!("{}", i));
+}
+```
diff --git a/src/doc/unstable-book/src/library-features/more-io-inner-methods.md b/src/doc/unstable-book/src/library-features/more-io-inner-methods.md
deleted file mode 100644
index c84f40e7ee5..00000000000
--- a/src/doc/unstable-book/src/library-features/more-io-inner-methods.md
+++ /dev/null
@@ -1,11 +0,0 @@
-# `more_io_inner_methods`
-
-The tracking issue for this feature is: [#41519]
-
-[#41519]: https://github.com/rust-lang/rust/issues/41519
-
-------------------------
-
-This feature enables several internal accessor methods on structures in
-`std::io` including `Take::{get_ref, get_mut}` and `Chain::{into_inner, get_ref,
-get_mut}`.
diff --git a/src/doc/unstable-book/src/library-features/sort-unstable.md b/src/doc/unstable-book/src/library-features/sort-unstable.md
deleted file mode 100644
index 9effcfc774c..00000000000
--- a/src/doc/unstable-book/src/library-features/sort-unstable.md
+++ /dev/null
@@ -1,40 +0,0 @@
-# `sort_unstable`
-
-The tracking issue for this feature is: [#40585]
-
-[#40585]: https://github.com/rust-lang/rust/issues/40585
-
-------------------------
-
-The default `sort` method on slices is stable. In other words, it guarantees
-that the original order of equal elements is preserved after sorting. The
-method has several undesirable characteristics:
-
-1. It allocates a sizable chunk of memory.
-2. If you don't need stability, it is not as performant as it could be.
-
-An alternative is the new `sort_unstable` feature, which includes these
-methods for sorting slices:
-
-1. `sort_unstable`
-2. `sort_unstable_by`
-3. `sort_unstable_by_key`
-
-Unstable sorting is generally faster and makes no allocations. The majority
-of real-world sorting needs doesn't require stability, so these methods can
-very often come in handy.
-
-Another important difference is that `sort` lives in `libstd` and
-`sort_unstable` lives in `libcore`. The reason is that the former makes
-allocations and the latter doesn't.
-
-A simple example:
-
-```rust
-#![feature(sort_unstable)]
-
-let mut v = [-5, 4, 1, -3, 2];
-
-v.sort_unstable();
-assert!(v == [-5, -3, 1, 2, 4]);
-```