Merge pull request #1326 from rossmacarthur/fix/unit-called-nil

Do not use "nil" to refer to `()`

Author: steveklabnik

src/custom_types/structs.md

@@ -16,7 +16,7 @@ struct Person<'a> {
 }
 
 // A unit struct
-struct Nil;
+struct Unit;
 
 // A tuple struct
 struct Pair(i32, f32);
@@ -70,7 +70,7 @@ fn main() {
     };
 
     // Instantiate a unit struct
-    let _nil = Nil;
+    let _unit = Unit;
 
     // Instantiate a tuple struct
     let pair = Pair(1, 0.1);

src/trait/clone.md

@@ -1,30 +1,30 @@
 # Clone
 
 When dealing with resources, the default behavior is to transfer them during
-assignments or function calls. However, sometimes we need to make a 
+assignments or function calls. However, sometimes we need to make a
 copy of the resource as well.
 
-The [`Clone`][clone] trait helps us do exactly this. Most commonly, we can 
+The [`Clone`][clone] trait helps us do exactly this. Most commonly, we can
 use the `.clone()` method defined by the `Clone` trait.
 
 ```rust,editable
 // A unit struct without resources
 #[derive(Debug, Clone, Copy)]
-struct Nil;
+struct Unit;
 
 // A tuple struct with resources that implements the `Clone` trait
 #[derive(Clone, Debug)]
 struct Pair(Box<i32>, Box<i32>);
 
 fn main() {
-    // Instantiate `Nil`
-    let nil = Nil;
-    // Copy `Nil`, there are no resources to move
-    let copied_nil = nil;
+    // Instantiate `Unit`
+    let unit = Unit;
+    // Copy `Unit`, there are no resources to move
+    let copied_unit = unit;
 
-    // Both `Nil`s can be used independently
-    println!("original: {:?}", nil);
-    println!("copy: {:?}", copied_nil);
+    // Both `Unit`s can be used independently
+    println!("original: {:?}", unit);
+    println!("copy: {:?}", copied_unit);
 
     // Instantiate `Pair`
     let pair = Pair(Box::new(1), Box::new(2));
@@ -37,7 +37,7 @@ fn main() {
     // Error! `pair` has lost its resources
     //println!("original: {:?}", pair);
     // TODO ^ Try uncommenting this line
-    
+
     // Clone `moved_pair` into `cloned_pair` (resources are included)
     let cloned_pair = moved_pair.clone();
     // Drop the original pair using std::mem::drop
@@ -52,4 +52,4 @@ fn main() {
 }
 ```
 
-[clone]: https://doc.rust-lang.org/std/clone/trait.Clone.html
+[clone]: https://doc.rust-lang.org/std/clone/trait.Clone.html