Auto merge of #35240 - sanxiyn:rollup, r=sanxiyn

Rollup of 7 pull requests

- Successful merges: #34319, #35041, #35042, #35175, #35181, #35182, #35189
- Failed merges:

Author: bors

src/doc/book/the-stack-and-the-heap.md

@@ -26,6 +26,8 @@ The stack is very fast, and is where memory is allocated in Rust by default.
 But the allocation is local to a function call, and is limited in size. The
 heap, on the other hand, is slower, and is explicitly allocated by your
 program. But it’s effectively unlimited in size, and is globally accessible.
+Note this meaning of heap, which allocates arbitrary-sized blocks of memory in arbitrary
+order, is quite different from the heap data structure.  
 
 # The Stack
 

src/libcollections/range.rs

@@ -23,13 +23,45 @@ pub trait RangeArgument<T> {
     /// Start index (inclusive)
     ///
     /// Return start value if present, else `None`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(collections)]
+    /// #![feature(collections_range)]
+    ///
+    /// extern crate collections;
+    ///
+    /// # fn main() {
+    /// use collections::range::RangeArgument;
+    ///
+    /// assert_eq!((..10).start(), None);
+    /// assert_eq!((3..10).start(), Some(&3));
+    /// # }
+    /// ```
     fn start(&self) -> Option<&T> {
         None
     }
 
     /// End index (exclusive)
     ///
     /// Return end value if present, else `None`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(collections)]
+    /// #![feature(collections_range)]
+    ///
+    /// extern crate collections;
+    ///
+    /// # fn main() {
+    /// use collections::range::RangeArgument;
+    ///
+    /// assert_eq!((3..).end(), None);
+    /// assert_eq!((3..10).end(), Some(&10));
+    /// # }
+    /// ```
     fn end(&self) -> Option<&T> {
         None
     }

src/libcollections/vec.rs

@@ -476,6 +476,25 @@ impl<T> Vec<T> {
     /// Note that this will drop any excess capacity. Calling this and
     /// converting back to a vector with `into_vec()` is equivalent to calling
     /// `shrink_to_fit()`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let v = vec![1, 2, 3];
+    ///
+    /// let slice = v.into_boxed_slice();
+    /// ```
+    ///
+    /// Any excess capacity is removed:
+    ///
+    /// ```
+    /// let mut vec = Vec::with_capacity(10);
+    /// vec.extend([1, 2, 3].iter().cloned());
+    ///
+    /// assert_eq!(vec.capacity(), 10);
+    /// let slice = vec.into_boxed_slice();
+    /// assert_eq!(slice.into_vec().capacity(), 3);
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn into_boxed_slice(mut self) -> Box<[T]> {
         unsafe {

src/libcore/marker.rs

@@ -144,6 +144,12 @@ pub trait Unsize<T: ?Sized> {
 /// Generalizing the latter case, any type implementing `Drop` can't be `Copy`, because it's
 /// managing some resource besides its own `size_of::<T>()` bytes.
 ///
+/// ## What if I derive `Copy` on a type that can't?
+///
+/// If you try to derive `Copy` on a struct or enum, you will get a compile-time error.
+/// Specifically, with structs you'll get [E0204](https://doc.rust-lang.org/error-index.html#E0204)
+/// and with enums you'll get [E0205](https://doc.rust-lang.org/error-index.html#E0205).
+///
 /// ## When should my type be `Copy`?
 ///
 /// Generally speaking, if your type _can_ implement `Copy`, it should. There's one important thing

src/librustc_typeck/diagnostics.rs

@@ -3897,6 +3897,104 @@ impl SpaceLlama for i32 {
 ```
 "##,
 
+E0527: r##"
+The number of elements in an array or slice pattern differed from the number of
+elements in the array being matched.
+
+Example of erroneous code:
+
+```compile_fail,E0527
+#![feature(slice_patterns)]
+
+let r = &[1, 2, 3, 4];
+match r {
+    &[a, b] => { // error: pattern requires 2 elements but array
+                 //        has 4
+        println!("a={}, b={}", a, b);
+    }
+}
+```
+
+Ensure that the pattern is consistent with the size of the matched
+array. Additional elements can be matched with `..`:
+
+```
+#![feature(slice_patterns)]
+
+let r = &[1, 2, 3, 4];
+match r {
+    &[a, b, ..] => { // ok!
+        println!("a={}, b={}", a, b);
+    }
+}
+```
+"##,
+
+E0528: r##"
+An array or slice pattern required more elements than were present in the
+matched array.
+
+Example of erroneous code:
+
+```compile_fail,E0528
+#![feature(slice_patterns)]
+
+let r = &[1, 2];
+match r {
+    &[a, b, c, rest..] => { // error: pattern requires at least 3
+                            //        elements but array has 2
+        println!("a={}, b={}, c={} rest={:?}", a, b, c, rest);
+    }
+}
+```
+
+Ensure that the matched array has at least as many elements as the pattern
+requires. You can match an arbitrary number of remaining elements with `..`:
+
+```
+#![feature(slice_patterns)]
+
+let r = &[1, 2, 3, 4, 5];
+match r {
+    &[a, b, c, rest..] => { // ok!
+        // prints `a=1, b=2, c=3 rest=[4, 5]`
+        println!("a={}, b={}, c={} rest={:?}", a, b, c, rest);
+    }
+}
+```
+"##,
+
+E0529: r##"
+An array or slice pattern was matched against some other type.
+
+Example of erroneous code:
+
+```compile_fail,E0529
+#![feature(slice_patterns)]
+
+let r: f32 = 1.0;
+match r {
+    [a, b] => { // error: expected an array or slice, found `f32`
+        println!("a={}, b={}", a, b);
+    }
+}
+```
+
+Ensure that the pattern and the expression being matched on are of consistent
+types:
+
+```
+#![feature(slice_patterns)]
+
+let r = [1.0, 2.0];
+match r {
+    [a, b] => { // ok!
+        println!("a={}, b={}", a, b);
+    }
+}
+```
+"##,
+
 E0559: r##"
 An unknown field was specified into an enum's structure variant.
 
@@ -4018,8 +4116,5 @@ register_diagnostics! {
     E0436, // functional record update requires a struct
     E0513, // no type for local variable ..
     E0521, // redundant default implementations of trait
-    E0527, // expected {} elements, found {}
-    E0528, // expected at least {} elements, found {}
-    E0529, // slice pattern expects array or slice, not `{}`
     E0533, // `{}` does not name a unit variant, unit struct or a constant
 }

src/libstd/ffi/c_str.rs

@@ -356,6 +356,18 @@ impl Borrow<CStr> for CString {
 impl NulError {
     /// Returns the position of the nul byte in the slice that was provided to
     /// `CString::new`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::ffi::CString;
+    ///
+    /// let nul_error = CString::new("foo\0bar").unwrap_err();
+    /// assert_eq!(nul_error.nul_position(), 3);
+    ///
+    /// let nul_error = CString::new("foo bar\0").unwrap_err();
+    /// assert_eq!(nul_error.nul_position(), 7);
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn nul_position(&self) -> usize { self.0 }
 

src/libstd/net/mod.rs

@@ -35,7 +35,11 @@ mod udp;
 mod parser;
 #[cfg(test)] mod test;
 
-/// Possible values which can be passed to the `shutdown` method of `TcpStream`.
+/// Possible values which can be passed to the [`shutdown`] method of
+/// [`TcpStream`].
+///
+/// [`shutdown`]: struct.TcpStream.html#method.shutdown
+/// [`TcpStream`]: struct.TcpStream.html
 #[derive(Copy, Clone, PartialEq, Debug)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Shutdown {

src/libstd/net/tcp.rs

@@ -77,6 +77,11 @@ pub struct TcpListener(net_imp::TcpListener);
 ///
 /// This iterator will infinitely yield `Some` of the accepted connections. It
 /// is equivalent to calling `accept` in a loop.
+///
+/// This `struct` is created by the [`incoming`] method on [`TcpListener`].
+///
+/// [`incoming`]: struct.TcpListener.html#method.incoming
+/// [`TcpListener`]: struct.TcpListener.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Incoming<'a> { listener: &'a TcpListener }