From 498ac2997420f7b25f7cd0a3f8202950d8ad93ec Mon Sep 17 00:00:00 2001
From: Simon Sapin <simon.sapin@exyr.org>
Date: Fri, 6 Apr 2018 00:30:20 +0200
Subject: [PATCH] Use the new GlobalAlloc trait

---
 src/destructors.md | 16 ++++++++--------
 src/vec-final.md   | 21 ++++++++++-----------
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/src/destructors.md b/src/destructors.md
index 6656747..7b6b47e 100644
--- a/src/destructors.md
+++ b/src/destructors.md
@@ -28,7 +28,7 @@ For instance, a custom implementation of `Box` might write `Drop` like this:
 ```rust
 #![feature(ptr_internals, allocator_api, unique)]
 
-use std::heap::{Heap, Alloc, Layout};
+use std::alloc::{Global, GlobalAlloc, Layout, Void};
 use std::mem;
 use std::ptr::{drop_in_place, Unique};
 
@@ -38,7 +38,7 @@ impl<T> Drop for Box<T> {
     fn drop(&mut self) {
         unsafe {
             drop_in_place(self.ptr.as_ptr());
-            Heap.dealloc(self.ptr.as_ptr() as *mut u8, Layout::new::<T>())
+            Global.dealloc(self.ptr.as_ptr() as *mut Void, Layout::new::<T>())
         }
     }
 }
@@ -54,7 +54,7 @@ However this wouldn't work:
 ```rust
 #![feature(allocator_api, ptr_internals, unique)]
 
-use std::heap::{Heap, Alloc, Layout};
+use std::alloc::{Global, GlobalAlloc, Layout, Void};
 use std::ptr::{drop_in_place, Unique};
 use std::mem;
 
@@ -64,7 +64,7 @@ impl<T> Drop for Box<T> {
     fn drop(&mut self) {
         unsafe {
             drop_in_place(self.ptr.as_ptr());
-            Heap.dealloc(self.ptr.as_ptr() as *mut u8, Layout::new::<T>());
+            Global.dealloc(self.ptr.as_ptr() as *mut Void, Layout::new::<T>());
         }
     }
 }
@@ -76,7 +76,7 @@ impl<T> Drop for SuperBox<T> {
         unsafe {
             // Hyper-optimized: deallocate the box's contents for it
             // without `drop`ing the contents
-            Heap.dealloc(self.my_box.ptr.as_ptr() as *mut u8, Layout::new::<T>());
+            Global.dealloc(self.my_box.ptr.as_ptr() as *mut Void, Layout::new::<T>());
         }
     }
 }
@@ -125,7 +125,7 @@ of Self during `drop` is to use an Option:
 ```rust
 #![feature(allocator_api, ptr_internals, unique)]
 
-use std::heap::{Alloc, Heap, Layout};
+use std::alloc::{GlobalAlloc, Global, Layout, Void};
 use std::ptr::{drop_in_place, Unique};
 use std::mem;
 
@@ -135,7 +135,7 @@ impl<T> Drop for Box<T> {
     fn drop(&mut self) {
         unsafe {
             drop_in_place(self.ptr.as_ptr());
-            Heap.dealloc(self.ptr.as_ptr() as *mut u8, Layout::new::<T>());
+            Global.dealloc(self.ptr.as_ptr() as *mut Void, Layout::new::<T>());
         }
     }
 }
@@ -149,7 +149,7 @@ impl<T> Drop for SuperBox<T> {
             // without `drop`ing the contents. Need to set the `box`
             // field as `None` to prevent Rust from trying to Drop it.
             let my_box = self.my_box.take().unwrap();
-            Heap.dealloc(my_box.ptr.as_ptr() as *mut u8, Layout::new::<T>());
+            Global.dealloc(my_box.ptr.as_ptr() as *mut Void, Layout::new::<T>());
             mem::forget(my_box);
         }
     }
diff --git a/src/vec-final.md b/src/vec-final.md
index 70a7a6b..110d5e2 100644
--- a/src/vec-final.md
+++ b/src/vec-final.md
@@ -9,7 +9,7 @@ use std::ptr::{Unique, self};
 use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::marker::PhantomData;
-use std::heap::{Alloc, Layout, Heap};
+use std::alloc::{GlobalAlloc, Layout, Global};
 
 struct RawVec<T> {
     ptr: Unique<T>,
@@ -34,21 +34,20 @@ impl<T> RawVec<T> {
             assert!(elem_size != 0, "capacity overflow");
 
             let (new_cap, ptr) = if self.cap == 0 {
-                let ptr = Heap.alloc(Layout::array::<T>(1).unwrap());
+                let ptr = Global.alloc(Layout::array::<T>(1).unwrap());
                 (1, ptr)
             } else {
                 let new_cap = 2 * self.cap;
-                let ptr = Heap.realloc(self.ptr.as_ptr() as *mut _,
-                                       Layout::array::<T>(self.cap).unwrap(),
-                                       Layout::array::<T>(new_cap).unwrap());
+                let ptr = Global.realloc(self.ptr.as_ptr() as *mut _,
+                                         Layout::array::<T>(self.cap).unwrap(),
+                                         Layout::array::<T>(new_cap).unwrap().size());
                 (new_cap, ptr)
             };
 
             // If allocate or reallocate fail, oom
-            let ptr = match ptr {
-                Ok(ptr) => ptr,
-                Err(err) => Heap.oom(err),
-            };
+            if ptr.is_null() {
+                Global.oom()
+            }
 
             self.ptr = Unique::new_unchecked(ptr as *mut _);
             self.cap = new_cap;
@@ -61,8 +60,8 @@ impl<T> Drop for RawVec<T> {
         let elem_size = mem::size_of::<T>();
         if self.cap != 0 && elem_size != 0 {
             unsafe {
-                Heap.dealloc(self.ptr.as_ptr() as *mut _,
-                             Layout::array::<T>(self.cap).unwrap());
+                Global.dealloc(self.ptr.as_ptr() as *mut _,
+                               Layout::array::<T>(self.cap).unwrap());
             }
         }
     }