Auto merge of #36126 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 16 pull requests

- Successful merges: #35418, #35759, #35862, #35863, #35895, #35962, #35977, #35993, #35997, #36054, #36056, #36060, #36086, #36100, #36103, #36125
- Failed merges: #35771, #35810

Author: bors

src/doc/book/compiler-plugins.md

@@ -46,10 +46,10 @@ extern crate rustc;
 extern crate rustc_plugin;
 
 use syntax::parse::token;
-use syntax::ast::TokenTree;
+use syntax::tokenstream::TokenTree;
 use syntax::ext::base::{ExtCtxt, MacResult, DummyResult, MacEager};
 use syntax::ext::build::AstBuilder;  // trait for expr_usize
-use syntax_pos::Span;
+use syntax::ext::quote::rt::Span;
 use rustc_plugin::Registry;
 
 fn expand_rn(cx: &mut ExtCtxt, sp: Span, args: &[TokenTree])
@@ -69,7 +69,7 @@ fn expand_rn(cx: &mut ExtCtxt, sp: Span, args: &[TokenTree])
     }
 
     let text = match args[0] {
-        TokenTree::Token(_, token::Ident(s, _)) => s.to_string(),
+        TokenTree::Token(_, token::Ident(s)) => s.to_string(),
         _ => {
             cx.span_err(sp, "argument should be a single identifier");
             return DummyResult::any(sp);

src/liballoc/arc.rs

@@ -71,6 +71,12 @@ const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 /// does not use atomics, making it both thread-unsafe as well as significantly
 /// faster when updating the reference count.
 ///
+/// Note: the inherent methods defined on `Arc<T>` are all associated functions,
+/// which means that you have to call them as e.g.  `Arc::get_mut(&value)`
+/// instead of `value.get_mut()`.  This is so that there are no conflicts with
+/// methods on the inner type `T`, which are what you want to call in the
+/// majority of cases.
+///
 /// # Examples
 ///
 /// In this example, a large vector of data will be shared by several threads. First we

src/liballoc/boxed.rs

@@ -271,6 +271,10 @@ impl<T: ?Sized> Box<T> {
     /// proper way to do so is to convert the raw pointer back into a
     /// `Box` with the `Box::from_raw` function.
     ///
+    /// Note: this is an associated function, which means that you have
+    /// to call it as `Box::into_raw(b)` instead of `b.into_raw()`. This
+    /// is so that there is no conflict with a method on the inner type.
+    ///
     /// # Examples
     ///
     /// ```

src/liballoc/rc.rs

@@ -182,6 +182,12 @@ struct RcBox<T: ?Sized> {
 /// A reference-counted pointer type over an immutable value.
 ///
 /// See the [module level documentation](./index.html) for more details.
+///
+/// Note: the inherent methods defined on `Rc<T>` are all associated functions,
+/// which means that you have to call them as e.g. `Rc::get_mut(&value)` instead
+/// of `value.get_mut()`.  This is so that there are no conflicts with methods
+/// on the inner type `T`, which are what you want to call in the majority of
+/// cases.
 #[cfg_attr(stage0, unsafe_no_drop_flag)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Rc<T: ?Sized> {

src/libcollections/fmt.rs

@@ -165,9 +165,15 @@
 //! provides some helper methods.
 //!
 //! Additionally, the return value of this function is `fmt::Result` which is a
-//! typedef to `Result<(), std::io::Error>` (also known as `std::io::Result<()>`).
-//! Formatting implementations should ensure that they return errors from `write!`
-//! correctly (propagating errors upward).
+//! type alias of `Result<(), std::fmt::Error>`. Formatting implementations
+//! should ensure that they propagate errors from the `Formatter` (e.g., when
+//! calling `write!`) however, they should never return errors spuriously. That
+//! is, a formatting implementation must and may only return an error if the
+//! passed-in `Formatter` returns an error. This is because, contrary to what
+//! the function signature might suggest, string formatting is an infallible
+//! operation. This function only returns a result because writing to the
+//! underlying stream might fail and it must provide a way to propagate the fact
+//! that an error has occurred back up the stack.
 //!
 //! An example of implementing the formatting traits would look
 //! like:

src/libcore/cell.rs

@@ -119,26 +119,55 @@
 //! `Cell<T>`.
 //!
 //! ```
+//! #![feature(core_intrinsics)]
+//! #![feature(shared)]
 //! use std::cell::Cell;
+//! use std::ptr::Shared;
+//! use std::intrinsics::abort;
+//! use std::intrinsics::assume;
 //!
-//! struct Rc<T> {
-//!     ptr: *mut RcBox<T>
+//! struct Rc<T: ?Sized> {
+//!     ptr: Shared<RcBox<T>>
 //! }
 //!
-//! struct RcBox<T> {
-//! # #[allow(dead_code)]
+//! struct RcBox<T: ?Sized> {
+//!     strong: Cell<usize>,
+//!     refcount: Cell<usize>,
 //!     value: T,
-//!     refcount: Cell<usize>
 //! }
 //!
-//! impl<T> Clone for Rc<T> {
+//! impl<T: ?Sized> Clone for Rc<T> {
 //!     fn clone(&self) -> Rc<T> {
-//!         unsafe {
-//!             (*self.ptr).refcount.set((*self.ptr).refcount.get() + 1);
-//!             Rc { ptr: self.ptr }
-//!         }
+//!         self.inc_strong();
+//!         Rc { ptr: self.ptr }
+//!     }
+//! }
+//!
+//! trait RcBoxPtr<T: ?Sized> {
+//!
+//!     fn inner(&self) -> &RcBox<T>;
+//!
+//!     fn strong(&self) -> usize {
+//!         self.inner().strong.get()
+//!     }
+//!
+//!     fn inc_strong(&self) {
+//!         self.inner()
+//!             .strong
+//!             .set(self.strong()
+//!                      .checked_add(1)
+//!                      .unwrap_or_else(|| unsafe { abort() }));
 //!     }
 //! }
+//!
+//! impl<T: ?Sized> RcBoxPtr<T> for Rc<T> {
+//!    fn inner(&self) -> &RcBox<T> {
+//!        unsafe {
+//!            assume(!(*(&self.ptr as *const _ as *const *const ())).is_null());
+//!            &(**self.ptr)
+//!        }
+//!    }
+//! }
 //! ```
 //!