Merge pull request #472 from rust-lang/ch19-advanced-features.md

merge chapter 19-20 into 19

Author: steveklabnik

src/SUMMARY.md

@@ -88,9 +88,12 @@
 
 - [Patterns](ch18-00-patterns.md) (perhaps an appendix?)
 
-- [More Lifetimes](ch19-00-more-lifetimes.md) (perhaps merge this into advanced type system features?)
+- [Advanced Features](ch19-00-advanced-features.md)
+    - [Unsafe Rust](ch19-01-unsafe-rust.md)
+    - [Advanced Lifetimes](ch19-02-advanced-lifetimes.md)
+    - [Advanced Traits](ch19-03-advanced-traits.md)
 
-- [Advanced Type System Features](ch20-00-advanced-types.md) (perhaps called "Advanced Traits"?)
+- [Un-named project](ch20-00-unnamed-project.md)
 
 - [Appendix](appendix-00.md)
     - [Keywords](appendix-01-keywords.md)

src/ch19-00-advanced-features.md

@@ -0,0 +1,15 @@
+# Advanced Features
+
+We've come a long way! By now, we've learned 99% of the things you'll need to
+know when writing Rust. We'll wrap the book up by doing one more project, but
+before we get to that, let's talk about a few things that you may run into that
+last 1% of the time. Feel free to skip this chapter and come back to it once
+you run into these things in the wild; the tools we'll learn to use here are
+useful in very specific situations. We don't want to leave them out, but you
+won't find yourself reaching for them often.
+
+Here's a quick summary:
+
+* Unsafe Rust: for when you need to tell Rust "just trust me, promise!"
+* Advanced Lifetimes: Additional lifetime syntax for complex situations.
+* Advanced Traits: Associated Types, coherence, and disambiguation.

src/ch19-00-more-lifetimes.md

@@ -0,0 +1,32 @@
+# Unsafe Rust
+
+Things you may do in an unsafe block that you may not in safe rust
+
+- deref a raw pointer
+- call an unsafe fn
+- access or modify a static variable
+- impl an unsafe trait
+
+Go see other stuff
+
+Here's the syntax tho
+
+You know unsafe blocks are the cause of any crashes
+
+wrap all the unsafe, make it as small as possible, present a safe public API
+
+## Raw Pointers
+
+## Unsafe Functions
+
+### `transmute`
+
+never ever. don't. stop.
+
+### `extern fn`
+
+You have to write unsafe code to FFI
+
+## `static`
+
+## Unsafe Traits

src/ch19-01-unsafe-rust.md

@@ -0,0 +1,11 @@
+# Advanced Lifetimes
+
+### Lifetimes that depend on other lifetimes
+
+'a: 'b stuff: subtyping
+
+### Higher ranked trait bounds
+
+for<'a>
+
+Needed for closures

src/ch19-02-advanced-lifetimes.md

@@ -0,0 +1,23 @@
+# Advanced Traits
+
+## Associated Types
+
+More common than the other things, less common than the rest of the book
+
+why this is a thing instead of a generic
+
+## The Thing Formerly Known as UFCS
+
+Only needed when implementing super generic code
+
+Lots of things are syntax sugar for this
+
+Two traits that impl the same method - how to disambiguate
+
+## Coherence
+
+Show examples of when you control traits and types or not
+
+Ex: Cannot impl Debug on someone else's type
+
+Solution: newtype

src/ch19-03-advanced-traits.md

@@ -0,0 +1 @@
+# Un-named project