Update vector code examples

The code samples were different from the final code and included
deprecated API calls.

Author: lukas9393

src/vec-alloc.md

@@ -16,10 +16,6 @@ want to use `dangling` because there's no real allocation to talk about but
 So:
 
 ```rust,ignore
-#![feature(alloc, heap_api)]
-
-use std::mem;
-
 impl<T> Vec<T> {
     fn new() -> Self {
         assert!(mem::size_of::<T>() != 0, "We're not ready to handle ZSTs");
@@ -76,9 +72,7 @@ compiler to be able to reason about data dependencies and aliasing.
 
 As a simple example, consider the following fragment of code:
 
-```rust
-# let x = &mut 0;
-# let y = &mut 0;
+```rust,ignore
 *x *= 7;
 *y *= 3;
 ```
@@ -158,22 +152,18 @@ such we will guard against this case explicitly.
 Ok with all the nonsense out of the way, let's actually allocate some memory:
 
 ```rust,ignore
-use std::alloc::oom;
-
 fn grow(&mut self) {
     // this is all pretty delicate, so let's say it's all unsafe
     unsafe {
-        // current API requires us to specify size and alignment manually.
-        let align = mem::align_of::<T>();
         let elem_size = mem::size_of::<T>();
 
         let (new_cap, ptr) = if self.cap == 0 {
-            let ptr = heap::allocate(elem_size, align);
+            let ptr = Global.allocate(Layout::array::<T>(1).unwrap());
             (1, ptr)
         } else {
             // as an invariant, we can assume that `self.cap < isize::MAX`,
             // so this doesn't need to be checked.
-            let new_cap = self.cap * 2;
+            let new_cap = 2 * self.cap;
             // Similarly this can't overflow due to previously allocating this
             let old_num_bytes = self.cap * elem_size;
 
@@ -186,23 +176,28 @@ fn grow(&mut self) {
             assert!(old_num_bytes <= (isize::MAX as usize) / 2,
                     "capacity overflow");
 
-            let new_num_bytes = old_num_bytes * 2;
-            let ptr = heap::reallocate(self.ptr.as_ptr() as *mut _,
-                                        old_num_bytes,
-                                        new_num_bytes,
-                                        align);
+            let c: NonNull<T> = self.ptr.into();
+            let ptr = Global.grow(c.cast(),
+                                  Layout::array::<T>(self.cap).unwrap(),
+                                  Layout::array::<T>(new_cap).unwrap());
             (new_cap, ptr)
         };
 
-        // If allocate or reallocate fail, we'll get `null` back
-        if ptr.is_null() { oom(); }
+        // If allocate or reallocate fail, oom
+        if ptr.is_err() {
+            handle_alloc_error(Layout::from_size_align_unchecked(
+                new_cap * elem_size,
+                mem::align_of::<T>(),
+            ))
+        }
+
+        let ptr = ptr.unwrap();
 
-        self.ptr = Unique::new(ptr as *mut _);
+        self.ptr = Unique::new_unchecked(ptr.as_ptr() as *mut _);
         self.cap = new_cap;
     }
 }
 ```
 
 Nothing particularly tricky here. Just computing sizes and alignments and doing
 some careful multiplication checks.
-

src/vec-dealloc.md

@@ -7,7 +7,7 @@ ask Rust if `T` `needs_drop` and omit the calls to `pop`. However in practice
 LLVM is *really* good at removing simple side-effect free code like this, so I
 wouldn't bother unless you notice it's not being stripped (in this case it is).
 
-We must not call `heap::deallocate` when `self.cap == 0`, as in this case we
+We must not call `Global.deallocate` when `self.cap == 0`, as in this case we
 haven't actually allocated any memory.
 
 
@@ -17,11 +17,10 @@ impl<T> Drop for Vec<T> {
         if self.cap != 0 {
             while let Some(_) = self.pop() { }
 
-            let align = mem::align_of::<T>();
-            let elem_size = mem::size_of::<T>();
-            let num_bytes = elem_size * self.cap;
             unsafe {
-                heap::deallocate(self.ptr.as_ptr() as *mut _, num_bytes, align);
+                let c: NonNull<T> = self.ptr.into();
+                Global.deallocate(c.cast(),
+                                  Layout::array::<T>(self.cap).unwrap());
             }
         }
     }

src/vec-drain.md

@@ -26,7 +26,7 @@ impl<'a, T> Iterator for Drain<'a, T> {
 -- wait, this is seeming familiar. Let's do some more compression. Both
 IntoIter and Drain have the exact same structure, let's just factor it out.
 
-```rust
+```rust,ignore
 struct RawValIter<T> {
     start: *const T,
     end: *const T,
@@ -75,7 +75,7 @@ impl<T> DoubleEndedIterator for IntoIter<T> {
 
 impl<T> Drop for IntoIter<T> {
     fn drop(&mut self) {
-        for _ in &mut self.iter {}
+        for _ in &mut *self {}
     }
 }
 
@@ -123,7 +123,7 @@ impl<'a, T> DoubleEndedIterator for Drain<'a, T> {
 
 impl<'a, T> Drop for Drain<'a, T> {
     fn drop(&mut self) {
-        for _ in &mut self.iter {}
+        for _ in &mut *self {}
     }
 }
 

src/vec-final.md

@@ -174,7 +174,7 @@ impl<T> Vec<T> {
 impl<T> Drop for Vec<T> {
     fn drop(&mut self) {
         while let Some(_) = self.pop() {}
-        // allocation is handled by RawVec
+        // deallocation is handled by RawVec
     }
 }
 
@@ -214,7 +214,7 @@ impl<T> RawValIter<T> {
                 slice.as_ptr()
             } else {
                 slice.as_ptr().offset(slice.len() as isize)
-            }
+            },
         }
     }
 }
@@ -307,18 +307,18 @@ impl<'a, T> DoubleEndedIterator for Drain<'a, T> {
 impl<'a, T> Drop for Drain<'a, T> {
     fn drop(&mut self) {
         // pre-drain the iter
-        for _ in &mut self.iter {}
+        for _ in &mut *self {}
     }
 }
-
+#
 # fn main() {
 #     tests::create_push_pop();
 #     tests::iter_test();
 #     tests::test_drain();
 #     tests::test_zst();
 #     println!("All tests finished OK");
 # }
-
+#
 # mod tests {
 #     use super::*;
 #     pub fn create_push_pop() {

src/vec-insert-remove.md

@@ -22,11 +22,11 @@ pub fn insert(&mut self, index: usize, elem: T) {
     unsafe {
         if index < self.len {
             // ptr::copy(src, dest, len): "copy from source to dest len elems"
-            ptr::copy(self.ptr.offset(index as isize),
-                      self.ptr.offset(index as isize + 1),
+            ptr::copy(self.ptr.as_ptr().offset(index as isize),
+                      self.ptr.as_ptr().offset(index as isize + 1),
                       self.len - index);
         }
-        ptr::write(self.ptr.offset(index as isize), elem);
+        ptr::write(self.ptr.as_ptr().offset(index as isize), elem);
         self.len += 1;
     }
 }
@@ -41,9 +41,9 @@ pub fn remove(&mut self, index: usize) -> T {
     assert!(index < self.len, "index out of bounds");
     unsafe {
         self.len -= 1;
-        let result = ptr::read(self.ptr.offset(index as isize));
-        ptr::copy(self.ptr.offset(index as isize + 1),
-                  self.ptr.offset(index as isize),
+        let result = ptr::read(self.ptr.as_ptr().offset(index as isize));
+        ptr::copy(self.ptr.as_ptr().offset(index as isize + 1),
+                  self.ptr.as_ptr().offset(index as isize),
                   self.len - index);
         result
     }

src/vec-into-iter.md

@@ -43,7 +43,7 @@ dropped.
 So we're going to use the following struct:
 
 ```rust,ignore
-struct IntoIter<T> {
+pub struct IntoIter<T> {
     buf: Unique<T>,
     cap: usize,
     start: *const T,
@@ -55,7 +55,7 @@ And this is what we end up with for initialization:
 
 ```rust,ignore
 impl<T> Vec<T> {
-    fn into_iter(self) -> IntoIter<T> {
+    pub fn into_iter(self) -> IntoIter<T> {
         // Can't destructure Vec since it's Drop
         let ptr = self.ptr;
         let cap = self.cap;
@@ -68,13 +68,13 @@ impl<T> Vec<T> {
             IntoIter {
                 buf: ptr,
                 cap: cap,
-                start: *ptr,
+                start: ptr.as_ptr(),
                 end: if cap == 0 {
                     // can't offset off this pointer, it's not allocated!
-                    *ptr
+                    ptr.as_ptr()
                 } else {
-                    ptr.offset(len as isize)
-                }
+                    ptr.as_ptr().offset(len as isize)
+                },
             }
         }
     }
@@ -135,11 +135,10 @@ impl<T> Drop for IntoIter<T> {
             // drop any remaining elements
             for _ in &mut *self {}
 
-            let align = mem::align_of::<T>();
-            let elem_size = mem::size_of::<T>();
-            let num_bytes = elem_size * self.cap;
             unsafe {
-                heap::deallocate(self.buf.as_ptr() as *mut _, num_bytes, align);
+                let c: NonNull<T> = self.buf.into();
+                Global.deallocate(c.cast(),
+                                  Layout::array::<T>(self.cap).unwrap());
             }
         }
     }

src/vec-layout.md

@@ -6,13 +6,12 @@ elements that have been initialized.
 
 Naively, this means we just want this design:
 
-```rust
+```rust,ignore
 pub struct Vec<T> {
     ptr: *mut T,
     cap: usize,
     len: usize,
 }
-# fn main() {}
 ```
 
 And indeed this would compile. Unfortunately, it would be incorrect. First, the
@@ -37,7 +36,7 @@ As a recap, Unique is a wrapper around a raw pointer that declares that:
 We can implement all of the above requirements except for the last
 one in stable Rust:
 
-```rust
+```rust,ignore
 use std::marker::PhantomData;
 use std::ops::Deref;
 use std::mem;
@@ -61,27 +60,19 @@ impl<T> Unique<T> {
         self.ptr as *mut T
     }
 }
-
-# fn main() {}
 ```
 
 Unfortunately the mechanism for stating that your value is non-zero is
 unstable and unlikely to be stabilized soon. As such we're just going to
 take the hit and use std's Unique:
 
 
-```rust
-#![feature(ptr_internals)]
-
-use std::ptr::{Unique, self};
-
+```rust,ignore
 pub struct Vec<T> {
     ptr: Unique<T>,
     cap: usize,
     len: usize,
 }
-
-# fn main() {}
 ```
 
 If you don't care about the null-pointer optimization, then you can use the

src/vec-push-pop.md

@@ -22,7 +22,7 @@ pub fn push(&mut self, elem: T) {
     if self.len == self.cap { self.grow(); }
 
     unsafe {
-        ptr::write(self.ptr.offset(self.len as isize), elem);
+        ptr::write(self.ptr.as_ptr().offset(self.len as isize), elem);
     }
 
     // Can't fail, we'll OOM first.
@@ -48,7 +48,7 @@ pub fn pop(&mut self) -> Option<T> {
     } else {
         self.len -= 1;
         unsafe {
-            Some(ptr::read(self.ptr.offset(self.len as isize)))
+            Some(ptr::read(self.ptr.as_ptr().offset(self.len as isize)))
         }
     }
 }