Reproduce text changes from @brson PR 7176 and fix a typo therein

Author: rkbodenner

src/libextra/std.rc

@@ -10,10 +10,13 @@
 
 /*!
 
-The Rust "extras" library.
+Rust extras.
 
-The Rust extras library (`extra`) provides a number of useful features that
-are not required in or otherwise suitable for the standard library (`std`).
+The `extra` crate is a set of useful modules for a variety of
+purposes, including collections, numerics, I/O, serialization,
+and concurrency.
+
+Rust extras are part of the standard Rust distribution.
 
 */
 
@@ -22,7 +25,7 @@ are not required in or otherwise suitable for the standard library (`std`).
        uuid = "122bed0b-c19b-4b82-b0b7-7ae8aead7297",
        url = "https://github.com/mozilla/rust/tree/master/src/libextra")];
 
-#[comment = "The Rust extras library"];
+#[comment = "Rust extras"];
 #[license = "MIT/ASL2"];
 #[crate_type = "lib"];
 

src/libstd/core.rc

@@ -12,19 +12,20 @@
 
 # The Rust standard library
 
-The Rust standard library provides runtime features required by the language,
-including the task scheduler and memory allocators, as well as library
-support for Rust built-in types, platform abstractions, and other commonly
-used features.
-
-`std` includes modules corresponding to each of the integer types, each of
-the floating point types, the `bool` type, tuples, characters, strings
-(`str`), vectors (`vec`), managed boxes (`managed`), owned boxes (`owned`),
-and unsafe and borrowed pointers (`ptr`).  Additionally, `std` provides
-pervasive types (`option` and `result`), task creation and communication
-primitives (`task`, `comm`), platform abstractions (`os` and `path`), basic
-I/O abstractions (`io`), common traits (`kinds`, `ops`, `cmp`, `num`,
-`to_str`), and complete bindings to the C standard library (`libc`).
+The Rust standard library is a group of interrelated modules defining
+the core language traits, operations on built-in data types, collections,
+platform abstractions, the task scheduler, runtime support for language
+features and other common functionality.
+
+`std` includes modules corresponding to each of the integer types,
+each of the floating point types, the `bool` type, tuples, characters,
+strings (`str`), vectors (`vec`), managed boxes (`managed`), owned
+boxes (`owned`), and unsafe and borrowed pointers (`ptr`, `borrowed`).
+Additionally, `std` provides pervasive types (`option` and `result`),
+task creation and communication primitives (`task`, `comm`), platform
+abstractions (`os` and `path`), basic I/O abstractions (`io`), common
+traits (`kinds`, `ops`, `cmp`, `num`, `to_str`), and complete bindings
+to the C standard library (`libc`).
 
 # Standard library injection and the Rust prelude
 
@@ -38,7 +39,7 @@ with the `std::` path prefix, as in `use std::vec`, `use std::task::spawn`,
 etc.
 
 Additionally, `std` contains a `prelude` module that reexports many of the
-most common `std` modules, types and traits. The contents of the prelude are
+most common types, traits and functions. The contents of the prelude are
 imported into every *module* by default.  Implicitly, all modules behave as if
 they contained the following prologue: