diff --git a/checked-uninit.md b/checked-uninit.md
index 667afe0..65bffd7 100644
--- a/checked-uninit.md
+++ b/checked-uninit.md
@@ -4,7 +4,7 @@ Like C, all stack variables in Rust are uninitialized until a value is
 explicitly assigned to them. Unlike C, Rust statically prevents you from ever
 reading them until you do:
 
-```rust
+```rust,ignore
 fn main() {
     let x: i32;
     println!("{}", x);
@@ -39,7 +39,7 @@ fn main() {
 
 but this doesn't:
 
-```rust
+```rust,ignore
 fn main() {
     let x: i32;
     if true {
diff --git a/coercions.md b/coercions.md
index fad9b09..df0fdfa 100644
--- a/coercions.md
+++ b/coercions.md
@@ -51,7 +51,7 @@ receivers, see below). If there is an impl for some type `U` and `T` coerces to
 following will not type check, even though it is OK to coerce `t` to `&T` and
 there is an impl for `&T`:
 
-```rust
+```rust,ignore
 trait Trait {}
 
 fn foo<X: Trait>(t: X) {}
diff --git a/destructors.md b/destructors.md
index cf6378c..e146ae4 100644
--- a/destructors.md
+++ b/destructors.md
@@ -3,7 +3,7 @@
 What the language *does* provide is full-blown automatic destructors through the
 `Drop` trait, which provides the following method:
 
-```rust
+```rust,ignore
 fn drop(&mut self);
 ```
 
@@ -23,13 +23,22 @@ this is totally fine.
 For instance, a custom implementation of `Box` might write `Drop` like this:
 
 ```rust
-struct Box<T>{ ptr: *mut T }
+#![feature(heap_api, core_intrinsics, unique)]
+
+use std::rt::heap;
+use std::ptr::Unique;
+use std::intrinsics::drop_in_place;
+use std::mem;
+
+struct Box<T>{ ptr: Unique<T> }
 
 impl<T> Drop for Box<T> {
     fn drop(&mut self) {
         unsafe {
-            (*self.ptr).drop();
-            heap::deallocate(self.ptr);
+            drop_in_place(*self.ptr);
+            heap::deallocate((*self.ptr) as *mut u8,
+                             mem::size_of::<T>(),
+                             mem::align_of::<T>());
         }
     }
 }
@@ -42,25 +51,36 @@ after-free the `ptr` because the Box is immediately marked as uninitialized.
 However this wouldn't work:
 
 ```rust
-struct Box<T>{ ptr: *mut T }
+#![feature(heap_api, core_intrinsics, unique)]
+
+use std::rt::heap;
+use std::ptr::Unique;
+use std::intrinsics::drop_in_place;
+use std::mem;
+
+struct Box<T>{ ptr: Unique<T> }
 
 impl<T> Drop for Box<T> {
     fn drop(&mut self) {
         unsafe {
-            (*self.ptr).drop();
-            heap::deallocate(self.ptr);
+            drop_in_place(*self.ptr);
+            heap::deallocate((*self.ptr) as *mut u8,
+                             mem::size_of::<T>(),
+                             mem::align_of::<T>());
         }
     }
 }
 
-struct SuperBox<T> { box: Box<T> }
+struct SuperBox<T> { my_box: Box<T> }
 
 impl<T> Drop for SuperBox<T> {
     fn drop(&mut self) {
         unsafe {
             // Hyper-optimized: deallocate the box's contents for it
             // without `drop`ing the contents
-            heap::deallocate(self.box.ptr);
+            heap::deallocate((*self.my_box.ptr) as *mut u8,
+                             mem::size_of::<T>(),
+                             mem::align_of::<T>());
         }
     }
 }
@@ -106,18 +126,27 @@ The classic safe solution to overriding recursive drop and allowing moving out
 of Self during `drop` is to use an Option:
 
 ```rust
-struct Box<T>{ ptr: *mut T }
+#![feature(heap_api, core_intrinsics, unique)]
+
+use std::rt::heap;
+use std::ptr::Unique;
+use std::intrinsics::drop_in_place;
+use std::mem;
+
+struct Box<T>{ ptr: Unique<T> }
 
 impl<T> Drop for Box<T> {
     fn drop(&mut self) {
         unsafe {
-            (*self.ptr).drop();
-            heap::deallocate(self.ptr);
+            drop_in_place(*self.ptr);
+            heap::deallocate((*self.ptr) as *mut u8,
+                             mem::size_of::<T>(),
+                             mem::align_of::<T>());
         }
     }
 }
 
-struct SuperBox<T> { box: Option<Box<T>> }
+struct SuperBox<T> { my_box: Option<Box<T>> }
 
 impl<T> Drop for SuperBox<T> {
     fn drop(&mut self) {
@@ -125,7 +154,11 @@ impl<T> Drop for SuperBox<T> {
             // Hyper-optimized: deallocate the box's contents for it
             // without `drop`ing the contents. Need to set the `box`
             // field as `None` to prevent Rust from trying to Drop it.
-            heap::deallocate(self.box.take().unwrap().ptr);
+            let my_box = self.my_box.take().unwrap();
+            heap::deallocate((*my_box.ptr) as *mut u8,
+                             mem::size_of::<T>(),
+                             mem::align_of::<T>());
+            mem::forget(my_box);
         }
     }
 }
diff --git a/drop-flags.md b/drop-flags.md
index 68f7ffc..e8c331c 100644
--- a/drop-flags.md
+++ b/drop-flags.md
@@ -31,6 +31,7 @@ And even branched code where all branches have the same behaviour with respect
 to initialization:
 
 ```rust
+# let condition = true;
 let mut x = Box::new(0);    // x was uninit; just overwrite.
 if condition {
     drop(x)                 // x gets moved out; make x uninit.
@@ -45,6 +46,7 @@ x = Box::new(0);            // x was uninit; just overwrite.
 However code like this *requires* runtime information to correctly Drop:
 
 ```rust
+# let condition = true;
 let x;
 if condition {
     x = Box::new(0);        // x was uninit; just overwrite.
@@ -56,6 +58,7 @@ if condition {
 Of course, in this case it's trivial to retrieve static drop semantics:
 
 ```rust
+# let condition = true;
 if condition {
     let x = Box::new(0);
     println!("{}", x);
diff --git a/exception-safety.md b/exception-safety.md
index ca33109..9a31934 100644
--- a/exception-safety.md
+++ b/exception-safety.md
@@ -156,7 +156,7 @@ way to do this is to store the algorithm's state in a separate struct with a
 destructor for the "finally" logic. Whether we panic or not, that destructor
 will run and clean up after us.
 
-```rust
+```rust,ignore
 struct Hole<'a, T: 'a> {
     data: &'a mut [T],
     /// `elt` is always `Some` from new until drop.
diff --git a/hrtb.md b/hrtb.md
index c3f2502..640742f 100644
--- a/hrtb.md
+++ b/hrtb.md
@@ -28,7 +28,7 @@ fn main() {
 If we try to naively desugar this code in the same way that we did in the
 lifetimes section, we run into some trouble:
 
-```rust
+```rust,ignore
 struct Closure<F> {
     data: (u8, u16),
     func: F,
@@ -60,7 +60,7 @@ we enter the body of `call`! Also, that isn't some fixed lifetime; call works wi
 This job requires The Magic of Higher-Rank Trait Bounds. The way we desugar
 this is as follows:
 
-```rust
+```rust,ignore
 where for<'a> F: Fn(&'a (u8, u16)) -> &'a u8,
 ```
 
@@ -69,4 +69,4 @@ where for<'a> F: Fn(&'a (u8, u16)) -> &'a u8,
 `for<'a>` can be read as "for all choices of `'a`", and basically produces an
 *inifinite list* of trait bounds that F must satisfy. Intense. There aren't many
 places outside of the Fn traits where we encounter HRTBs, and even for those we
-have a nice magic sugar for the common cases.
\ No newline at end of file
+have a nice magic sugar for the common cases.
diff --git a/leaking.md b/leaking.md
index 1e1e95a..bb6f7bb 100644
--- a/leaking.md
+++ b/leaking.md
@@ -68,7 +68,7 @@ unwinding-safe! Easy!
 
 Now consider the following:
 
-```
+```rust,ignore
 let mut vec = vec![Box::new(0); 4];
 
 {
@@ -118,7 +118,7 @@ Nope.
 
 Let's consider a simplified implementation of Rc:
 
-```rust
+```rust,ignore
 struct Rc<T> {
     ptr: *mut RcBox<T>,
 }
@@ -183,7 +183,7 @@ in memory.
 The thread::scoped API intends to allow threads to be spawned that reference
 data on the stack without any synchronization over that data. Usage looked like:
 
-```rust
+```rust,ignore
 let mut data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
 {
     let guards = vec![];
@@ -211,7 +211,7 @@ let mut data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
 In principle, this totally works! Rust's ownership system perfectly ensures it!
 ...except it relies on a destructor being called to be safe.
 
-```
+```rust,ignore
 let mut data = Box::new(0);
 {
     let guard = thread::scoped(|| {
diff --git a/lifetime-elision.md b/lifetime-elision.md
index eac2433..41014f4 100644
--- a/lifetime-elision.md
+++ b/lifetime-elision.md
@@ -5,7 +5,7 @@ In order to make common patterns more ergonomic, Rust allows lifetimes to be
 
 A *lifetime position* is anywhere you can write a lifetime in a type:
 
-```rust
+```rust,ignore
 &'a T
 &'a mut T
 T<'a>
@@ -38,7 +38,7 @@ Elision rules are as follows:
 
 Examples:
 
-```rust
+```rust,ignore
 fn print(s: &str);                                      // elided
 fn print<'a>(s: &'a str);                               // expanded
 
@@ -61,4 +61,4 @@ fn args<'a, 'b, T:ToCStr>(&'a mut self, args: &'b [T]) -> &'a mut Command // exp
 fn new(buf: &mut [u8]) -> BufWriter;                    // elided
 fn new<'a>(buf: &'a mut [u8]) -> BufWriter<'a>          // expanded
 
-```
\ No newline at end of file
+```
diff --git a/lifetime-misc.md b/lifetime-misc.md
index faf7f9a..bd44bb6 100644
--- a/lifetime-misc.md
+++ b/lifetime-misc.md
@@ -10,8 +10,8 @@ types or lifetimes are logically associated with a struct, but not actually
 part of a field. This most commonly occurs with lifetimes. For instance, the `Iter`
 for `&'a [T]` is (approximately) defined as follows:
 
-```rust
-pub struct Iter<'a, T: 'a> {
+```rust,ignore
+struct Iter<'a, T: 'a> {
     ptr: *const T,
     end: *const T,
 }
@@ -33,7 +33,9 @@ Iter logically contains `&'a T`, so this is exactly what we tell
 the PhantomData to simulate:
 
 ```
-pub struct Iter<'a, T: 'a> {
+use std::marker;
+
+struct Iter<'a, T: 'a> {
     ptr: *const T,
     end: *const T,
     _marker: marker::PhantomData<&'a T>,
@@ -68,6 +70,8 @@ tell dropck that we *do* own values of type T, and may call destructors of that
 type, we must add extra PhantomData:
 
 ```
+use std::marker;
+
 struct Vec<T> {
     data: *const T, // *const for covariance!
     len: usize,
@@ -115,7 +119,7 @@ println!("{} {} {} {}", a, b, c, c2);
 However borrowck doesn't understand arrays or slices in any way, so this doesn't
 work:
 
-```rust
+```rust,ignore
 let x = [1, 2, 3];
 let a = &mut x[0];
 let b = &mut x[1];
@@ -144,7 +148,7 @@ left of the index, and one for everything to the right. Intuitively we know this
 is safe because the slices don't alias. However the implementation requires some
 unsafety:
 
-```rust
+```rust,ignore
 fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) {
     unsafe {
         let self2: &mut [T] = mem::transmute_copy(&self);
@@ -189,8 +193,8 @@ Whether it's raw pointers, or safely composing on top of *another* IterMut.
 
 For instance, VecDeque's IterMut:
 
-```rust
-pub struct IterMut<'a, T:'a> {
+```rust,ignore
+struct IterMut<'a, T:'a> {
     // The whole backing array. Some of these indices are initialized!
     ring: &'a mut [T],
     tail: usize,
diff --git a/lifetimes.md b/lifetimes.md
index a06363a..7282e4d 100644
--- a/lifetimes.md
+++ b/lifetimes.md
@@ -38,7 +38,7 @@ let z = &y;
 The borrow checker always tries to minimize the extent of a lifetime, so it will
 likely desugar to the following:
 
-```rust
+```rust,ignore
 // NOTE: `'a: {` and `&'b x` is not valid syntax!
 'a: {
     let x: i32 = 0;
@@ -69,8 +69,8 @@ z = y;
 The borrow checker always tries to minimize the extent of a lifetime, so it will
 likely desugar to something like the following:
 
-```rust
-// NOTE: `'a: {` and `&'b x` is not valid syntax!
+```rust,ignore
+// NOTE: `'a: {` and `foo = &'b x` is not valid syntax!
 'a: {
     let x: i32 = 0;
     'b: {
@@ -174,14 +174,14 @@ our implementation *just a bit*.)
 
 How about the other example:
 
-```rust
+```rust,ignore
 let mut data = vec![1, 2, 3];
 let x = &data[0];
 data.push(4);
 println!("{}", x);
 ```
 
-```rust
+```rust,ignore
 'a: {
     let mut data: Vec<i32> = vec![1, 2, 3];
     'b: {
@@ -219,4 +219,4 @@ semantics we're actually interested in preserving. For the most part, *that's
 totally ok*, because it keeps us from spending all day explaining our program
 to the compiler. However it does mean that several programs that are *totally*
 correct with respect to Rust's *true* semantics are rejected because lifetimes
-are too dumb.
\ No newline at end of file
+are too dumb.
diff --git a/ownership.md b/ownership.md
index 9c4f92a..200337a 100644
--- a/ownership.md
+++ b/ownership.md
@@ -16,7 +16,7 @@ issue...). This is a pervasive problem that C and C++ need to deal with.
 Consider this simple mistake that all of us who have used a non-GC'd language
 have made at one point:
 
-```rust
+```rust,ignore
 fn as_str(data: &u32) -> &str {
     // compute the string
     let s = format!("{}", data);
@@ -45,7 +45,7 @@ verifying that references don't escape the scope of their referent. That's
 because ensuring pointers are always valid is much more complicated than this.
 For instance in this code,
 
-```rust
+```rust,ignore
 let mut data = vec![1, 2, 3];
 // get an internal reference
 let x = &data[0];
diff --git a/repr-rust.md b/repr-rust.md
index a1f5f29..b3a5a12 100644
--- a/repr-rust.md
+++ b/repr-rust.md
@@ -67,7 +67,7 @@ fields in the order specified, we expect it to *pad* the values in the struct to
 their *alignment* requirements. So if Rust didn't reorder fields, we would expect Rust to
 produce the following:
 
-```rust
+```rust,ignore
 struct Foo<u16, u32> {
     count: u16,
     data1: u16,
diff --git a/send-and-sync.md b/send-and-sync.md
index 6045d3d..5b00709 100644
--- a/send-and-sync.md
+++ b/send-and-sync.md
@@ -56,6 +56,8 @@ In the *incredibly rare* case that a type is *inappropriately* automatically
 derived to be Send or Sync, then one can also *unimplement* Send and Sync:
 
 ```rust
+#![feature(optin_builtin_traits)]
+
 struct SpecialThreadToken(u8);
 
 impl !Send for SpecialThreadToken {}
diff --git a/subtyping.md b/subtyping.md
index 24f974c..e43c365 100644
--- a/subtyping.md
+++ b/subtyping.md
@@ -104,7 +104,7 @@ However what should happen when passing *by-value* is less obvious. It turns out
 that, yes, you can use subtyping when passing by-value. That is, this works:
 
 ```rust
-fn get_box<'a>(&'a u8) -> Box<&'a str> {
+fn get_box<'a>(str: &'a u8) -> Box<&'a str> {
     // string literals are `&'static str`s
     Box::new("hello")
 }
@@ -123,7 +123,7 @@ must be invariant to avoid lifetime smuggling.
 `Fn(T) -> U` should be invariant over T, consider the following function
 signature:
 
-```rust
+```rust,ignore
 // 'a is derived from some parent scope
 fn foo(&'a str) -> usize;
 ```
@@ -131,7 +131,7 @@ fn foo(&'a str) -> usize;
 This signature claims that it can handle any `&str` that lives *at least* as long
 as `'a`. Now if this signature was variant with respect to `&str`, that would mean
 
-```rust
+```rust,ignore
 fn foo(&'static str) -> usize;
 ```
 
@@ -142,7 +142,7 @@ and nothing else. Therefore functions are not variant over their arguments.
 To see why `Fn(T) -> U` should be *variant* over U, consider the following
 function signature:
 
-```rust
+```rust,ignore
 // 'a is derived from some parent scope
 fn foo(usize) -> &'a str;
 ```
@@ -150,7 +150,7 @@ fn foo(usize) -> &'a str;
 This signature claims that it will return something that outlives `'a`. It is
 therefore completely reasonable to provide
 
-```rust
+```rust,ignore
 fn foo(usize) -> &'static str;
 ```
 
@@ -171,15 +171,17 @@ in multiple fields.
 * Otherwise, Foo is invariant over A
 
 ```rust
-struct Foo<'a, 'b, A, B, C, D, E, F, G, H> {
+use std::cell::Cell;
+
+struct Foo<'a, 'b, A: 'a, B: 'b, C, D, E, F, G, H> {
     a: &'a A,     // variant over 'a and A
     b: &'b mut B, // invariant over 'b and B
     c: *const C,  // variant over C
     d: *mut D,    // invariant over D
     e: Vec<E>,    // variant over E
     f: Cell<F>,   // invariant over F
-    g: G          // variant over G
-    h1: H         // would also be variant over H except...
-    h2: Cell<H>   // invariant over H, because invariance wins
+    g: G,         // variant over G
+    h1: H,        // would also be variant over H except...
+    h2: Cell<H>,  // invariant over H, because invariance wins
 }
-```
\ No newline at end of file
+```
diff --git a/unbounded-lifetimes.md b/unbounded-lifetimes.md
index 24caeeb..b540ab4 100644
--- a/unbounded-lifetimes.md
+++ b/unbounded-lifetimes.md
@@ -17,7 +17,7 @@ boundaries.
 Given a function, any output lifetimes that don't derive from inputs are
 unbounded. For instance:
 
-```rust
+```rust,ignore
 fn get_str<'a>() -> &'a str;
 ```
 
diff --git a/unchecked-uninit.md b/unchecked-uninit.md
index f5c0fb4..9ab97b9 100644
--- a/unchecked-uninit.md
+++ b/unchecked-uninit.md
@@ -46,27 +46,26 @@ locations of memory can break things are basically uncountable!
 Putting this all together, we get the following:
 
 ```rust
-fn main() {
-	use std::mem;
-
-	// size of the array is hard-coded but easy to change. This means we can't
-	// use [a, b, c] syntax to initialize the array, though!
-	const SIZE = 10;
-
-	let x: [Box<u32>; SIZE];
-
-	unsafe {
-		// convince Rust that x is Totally Initialized
-		x = mem::uninitialized();
-		for i in 0..SIZE {
-			// very carefully overwrite each index without reading it
-			// NOTE: exception safety is not a concern; Box can't panic
-			ptr::write(&mut x[i], Box::new(i));
-		}
+use std::mem;
+use std::ptr;
+
+// size of the array is hard-coded but easy to change. This means we can't
+// use [a, b, c] syntax to initialize the array, though!
+const SIZE: usize = 10;
+
+let mut x: [Box<u32>; SIZE];
+
+unsafe {
+	// convince Rust that x is Totally Initialized
+	x = mem::uninitialized();
+	for i in 0..SIZE {
+		// very carefully overwrite each index without reading it
+		// NOTE: exception safety is not a concern; Box can't panic
+		ptr::write(&mut x[i], Box::new(i as u32));
 	}
-
-	println!("{}", x);
 }
+
+println!("{:?}", x);
 ```
 
 It's worth noting that you don't need to worry about ptr::write-style
@@ -83,4 +82,4 @@ before it ends, if has a destructor.
 
 And that's about it for working with uninitialized memory! Basically nothing
 anywhere expects to be handed uninitialized memory, so if you're going to pass
-it around at all, be sure to be *really* careful.
\ No newline at end of file
+it around at all, be sure to be *really* careful.
diff --git a/vec-alloc.md b/vec-alloc.md
index a51f23c..e9c9f68 100644
--- a/vec-alloc.md
+++ b/vec-alloc.md
@@ -2,7 +2,7 @@
 
 So:
 
-```rust
+```rust,ignore
 #![feature(heap_api)]
 
 use std::rt::heap::EMPTY;
@@ -69,7 +69,7 @@ Anything else will use up too much space.
 However since this is a tutorial, we're not going to be particularly optimal here,
 and just unconditionally check, rather than use clever platform-specific `cfg`s.
 
-```rust
+```rust,ignore
 fn grow(&mut self) {
     // this is all pretty delicate, so let's say it's all unsafe
     unsafe {
diff --git a/vec-dealloc.md b/vec-dealloc.md
index a83d24d..2ae2477 100644
--- a/vec-dealloc.md
+++ b/vec-dealloc.md
@@ -11,13 +11,13 @@ We must not call `heap::deallocate` when `self.cap == 0`, as in this case we hav
 actually allocated any memory.
 
 
-```rust
+```rust,ignore
 impl<T> Drop for Vec<T> {
     fn drop(&mut self) {
         if self.cap != 0 {
             while let Some(_) = self.pop() { }
 
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
             let elem_size = mem::size_of::<T>();
             let num_bytes = elem_size * self.cap;
             unsafe {
diff --git a/vec-deref.md b/vec-deref.md
index b07d784..826d763 100644
--- a/vec-deref.md
+++ b/vec-deref.md
@@ -9,7 +9,7 @@ conditions.
 
 All we need is `slice::from_raw_parts`.
 
-```rust
+```rust,ignore
 use std::ops::Deref;
 
 impl<T> Deref for Vec<T> {
@@ -24,7 +24,7 @@ impl<T> Deref for Vec<T> {
 
 And let's do DerefMut too:
 
-```rust
+```rust,ignore
 use std::ops::DerefMut;
 
 impl<T> DerefMut for Vec<T> {
diff --git a/vec-drain.md b/vec-drain.md
index 0a53e8b..8dd085d 100644
--- a/vec-drain.md
+++ b/vec-drain.md
@@ -51,7 +51,7 @@ impl<T> RawValIter<T> {
 
 And IntoIter becomes the following:
 
-```
+```rust,ignore
 pub struct IntoIter<T> {
     _buf: RawVec<T>, // we don't actually care about this. Just need it to live.
     iter: RawValIter<T>,
@@ -96,7 +96,7 @@ We also take a slice to simplify Drain initialization.
 
 Alright, now Drain is really easy:
 
-```rust
+```rust,ignore
 use std::marker::PhantomData;
 
 pub struct Drain<'a, T: 'a> {
@@ -174,7 +174,7 @@ overflow for zero-sized types.
 Due to our current architecture, all this means is writing 3 guards, one in each
 method of RawVec.
 
-```rust
+```rust,ignore
 impl<T> RawVec<T> {
     fn new() -> Self {
         unsafe {
@@ -194,7 +194,7 @@ impl<T> RawVec<T> {
             // 0, getting to here necessarily means the Vec is overfull.
             assert!(elem_size != 0, "capacity overflow");
 
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
 
             let (new_cap, ptr) = if self.cap == 0 {
                 let ptr = heap::allocate(elem_size, align);
@@ -223,7 +223,7 @@ impl<T> Drop for RawVec<T> {
 
         // don't free zero-sized allocations, as they were never allocated.
         if self.cap != 0 && elem_size != 0 {
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
 
             let num_bytes = elem_size * self.cap;
             unsafe {
@@ -247,7 +247,7 @@ initialize `start` and `end` as the same value, and our iterators will yield
 nothing. The current solution to this is to cast the pointers to integers,
 increment, and then cast them back:
 
-```
+```rust,ignore
 impl<T> RawValIter<T> {
     unsafe fn new(slice: &[T]) -> Self {
         RawValIter {
@@ -270,7 +270,7 @@ Also, our size_hint computation code will divide by 0 for ZSTs. Since we'll
 basically be treating the two pointers as if they point to bytes, we'll just
 map size 0 to divide by 1.
 
-```
+```rust,ignore
 impl<T> Iterator for RawValIter<T> {
     type Item = T;
     fn next(&mut self) -> Option<T> {
@@ -315,4 +315,4 @@ impl<T> DoubleEndedIterator for RawValIter<T> {
 }
 ```
 
-And that's it. Iteration works!
\ No newline at end of file
+And that's it. Iteration works!
diff --git a/vec-final.md b/vec-final.md
index 96fcf6d..847957e 100644
--- a/vec-final.md
+++ b/vec-final.md
@@ -38,7 +38,7 @@ impl<T> RawVec<T> {
             // 0, getting to here necessarily means the Vec is overfull.
             assert!(elem_size != 0, "capacity overflow");
 
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
 
             let (new_cap, ptr) = if self.cap == 0 {
                 let ptr = heap::allocate(elem_size, align);
@@ -65,7 +65,7 @@ impl<T> Drop for RawVec<T> {
     fn drop(&mut self) {
         let elem_size = mem::size_of::<T>();
         if self.cap != 0 && elem_size != 0 {
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
 
             let num_bytes = elem_size * self.cap;
             unsafe {
@@ -306,4 +306,6 @@ impl<'a, T> Drop for Drain<'a, T> {
 fn oom() {
     ::std::process::exit(-9999);
 }
-```
\ No newline at end of file
+
+# fn main() {}
+```
diff --git a/vec-insert-remove.md b/vec-insert-remove.md
index 42d114c..f21ed22 100644
--- a/vec-insert-remove.md
+++ b/vec-insert-remove.md
@@ -11,7 +11,7 @@ here).
 If we insert at index `i`, we want to shift the `[i .. len]` to `[i+1 .. len+1]`
 using the *old* len.
 
-```rust
+```rust,ignore
 pub fn insert(&mut self, index: usize, elem: T) {
     // Note: `<=` because it's valid to insert after everything
     // which would be equivalent to push.
@@ -34,7 +34,7 @@ pub fn insert(&mut self, index: usize, elem: T) {
 Remove behaves in the opposite manner. We need to shift all the elements from
 `[i+1 .. len + 1]` to `[i .. len]` using the *new* len.
 
-```rust
+```rust,ignore
 pub fn remove(&mut self, index: usize) -> T {
     // Note: `<` because it's *not* valid to remove after everything
     assert!(index < self.len, "index out of bounds");
@@ -47,4 +47,4 @@ pub fn remove(&mut self, index: usize) -> T {
         result
     }
 }
-```
\ No newline at end of file
+```
diff --git a/vec-into-iter.md b/vec-into-iter.md
index b7e7d2b..d21cf94 100644
--- a/vec-into-iter.md
+++ b/vec-into-iter.md
@@ -37,7 +37,7 @@ indistinguishable from the case where there are no more elements to yield.
 
 So we're going to use the following struct:
 
-```rust
+```rust,ignore
 struct IntoIter<T> {
     buf: Unique<T>,
     cap: usize,
@@ -63,7 +63,7 @@ cap or len being 0 to not do the offset.
 
 So this is what we end up with for initialization:
 
-```rust
+```rust,ignore
 impl<T> Vec<T> {
     fn into_iter(self) -> IntoIter<T> {
         // Can't destructure Vec since it's Drop
@@ -93,7 +93,7 @@ impl<T> Vec<T> {
 
 Here's iterating forward:
 
-```rust
+```rust,ignore
 impl<T> Iterator for IntoIter<T> {
     type Item = T;
     fn next(&mut self) -> Option<T> {
@@ -118,7 +118,7 @@ impl<T> Iterator for IntoIter<T> {
 
 And here's iterating backwards.
 
-```rust
+```rust,ignore
 impl<T> DoubleEndedIterator for IntoIter<T> {
     fn next_back(&mut self) -> Option<T> {
         if self.start == self.end {
@@ -138,14 +138,14 @@ to free it. However it *also* wants to implement Drop to drop any elements it
 contains that weren't yielded.
 
 
-```rust
+```rust,ignore
 impl<T> Drop for IntoIter<T> {
     fn drop(&mut self) {
         if self.cap != 0 {
             // drop any remaining elements
             for _ in &mut *self {}
 
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
             let elem_size = mem::size_of::<T>();
             let num_bytes = elem_size * self.cap;
             unsafe {
@@ -164,7 +164,7 @@ compression.
 We're going to abstract out the `(ptr, cap)` pair and give them the logic for
 allocating, growing, and freeing:
 
-```rust
+```rust,ignore
 
 struct RawVec<T> {
     ptr: Unique<T>,
@@ -182,7 +182,7 @@ impl<T> RawVec<T> {
     // unchanged from Vec
     fn grow(&mut self) {
         unsafe {
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
             let elem_size = mem::size_of::<T>();
 
             let (new_cap, ptr) = if self.cap == 0 {
@@ -210,7 +210,7 @@ impl<T> RawVec<T> {
 impl<T> Drop for RawVec<T> {
     fn drop(&mut self) {
         if self.cap != 0 {
-            let align = mem::min_align_of::<T>();
+            let align = mem::align_of::<T>();
             let elem_size = mem::size_of::<T>();
             let num_bytes = elem_size * self.cap;
             unsafe {
@@ -223,7 +223,7 @@ impl<T> Drop for RawVec<T> {
 
 And change vec as follows:
 
-```rust
+```rust,ignore
 pub struct Vec<T> {
     buf: RawVec<T>,
     len: usize,
@@ -254,14 +254,14 @@ impl<T> Drop for Vec<T> {
 
 And finally we can really simplify IntoIter:
 
-```rust
+```rust,ignore
 struct IntoIter<T> {
     _buf: RawVec<T>, // we don't actually care about this. Just need it to live.
     start: *const T,
     end: *const T,
 }
 
-// next and next_back litterally unchanged since they never referred to the buf
+// next and next_back literally unchanged since they never referred to the buf
 
 impl<T> Drop for IntoIter<T> {
     fn drop(&mut self) {
@@ -290,4 +290,4 @@ impl<T> Vec<T> {
 }
 ```
 
-Much better.
\ No newline at end of file
+Much better.
diff --git a/vec-layout.md b/vec-layout.md
index 0f85e4d..128ad15 100644
--- a/vec-layout.md
+++ b/vec-layout.md
@@ -4,11 +4,13 @@ First off, we need to come up with the struct layout. Naively we want this
 design:
 
 ```rust
-struct Vec<T> {
+pub struct Vec<T> {
     ptr: *mut T,
     cap: usize,
     len: usize,
 }
+
+# fn main() {}
 ```
 
 And indeed this would compile. Unfortunately, it would be incorrect. The compiler
@@ -32,6 +34,8 @@ pub struct Vec<T> {
     cap: usize,
     len: usize,
 }
+
+# fn main() {}
 ```
 
 As a recap, Unique is a wrapper around a raw pointer that declares that:
diff --git a/vec-push-pop.md b/vec-push-pop.md
index d1584a2..2ef15e3 100644
--- a/vec-push-pop.md
+++ b/vec-push-pop.md
@@ -17,7 +17,7 @@ target address with the bits of the value we provide. No evaluation involved.
 For `push`, if the old len (before push was called) is 0, then we want to write
 to the 0th index. So we should offset by the old len.
 
-```rust
+```rust,ignore
 pub fn push(&mut self, elem: T) {
     if self.len == self.cap { self.grow(); }
 
@@ -41,7 +41,7 @@ of T there.
 For `pop`, if the old len is 1, we want to read out of the 0th index. So we
 should offset by the *new* len.
 
-```rust
+```rust,ignore
 pub fn pop(&mut self) -> Option<T> {
     if self.len == 0 {
         None
@@ -52,4 +52,4 @@ pub fn pop(&mut self) -> Option<T> {
         }
     }
 }
-```
\ No newline at end of file
+```
diff --git a/working-with-unsafe.md b/working-with-unsafe.md
index 69d0b31..0aeb2c0 100644
--- a/working-with-unsafe.md
+++ b/working-with-unsafe.md
@@ -5,7 +5,7 @@ binary manner. Unfortunately, reality is significantly more complicated than tha
 For instance, consider the following toy function:
 
 ```rust
-pub fn index(idx: usize, arr: &[u8]) -> Option<u8> {
+fn index(idx: usize, arr: &[u8]) -> Option<u8> {
     if idx < arr.len() {
         unsafe {
             Some(*arr.get_unchecked(idx))
@@ -22,7 +22,7 @@ function, the scope of the unsafe block is questionable. Consider changing the
 `<` to a `<=`:
 
 ```rust
-pub fn index(idx: usize, arr: &[u8]) -> Option<u8> {
+fn index(idx: usize, arr: &[u8]) -> Option<u8> {
     if idx <= arr.len() {
         unsafe {
             Some(*arr.get_unchecked(idx))
@@ -44,7 +44,9 @@ Trickier than that is when we get into actual statefulness. Consider a simple
 implementation of `Vec`:
 
 ```rust
-// Note this definition is insufficient. See the section on lifetimes.
+use std::ptr;
+
+// Note this definition is insufficient. See the section on implementing Vec.
 pub struct Vec<T> {
     ptr: *mut T,
     len: usize,
@@ -61,21 +63,25 @@ impl<T> Vec<T> {
             self.reallocate();
         }
         unsafe {
-            ptr::write(self.ptr.offset(len as isize), elem);
+            ptr::write(self.ptr.offset(self.len as isize), elem);
             self.len += 1;
         }
     }
+
+    # fn reallocate(&mut self) { }
 }
+
+# fn main() {}
 ```
 
 This code is simple enough to reasonably audit and verify. Now consider
 adding the following method:
 
-```rust
-    fn make_room(&mut self) {
-        // grow the capacity
-        self.cap += 1;
-    }
+```rust,ignore
+fn make_room(&mut self) {
+    // grow the capacity
+    self.cap += 1;
+}
 ```
 
 This code is safe, but it is also completely unsound. Changing the capacity