rollup merge of #24672: steveklabnik/edit_tuple_structs

I thought I edited all the last little chapters, but I missed this one.

r? @alexcrichton

Author: alexcrichton

src/doc/trpl/tuple-structs.md

@@ -1,16 +1,20 @@
 % Tuple Structs
 
-Rust has another data type that's like a hybrid between a tuple and a struct,
-called a *tuple struct*. Tuple structs do have a name, but their fields don't:
+Rust has another data type that's like a hybrid between a [tuple][tuple] and a
+[struct][struct], called a ‘tuple struct’. Tuple structs have a name, but
+their fields don’t:
 
-```{rust}
+```rust
 struct Color(i32, i32, i32);
 struct Point(i32, i32, i32);
 ```
 
+[tuple]: primitive-types.html#tuples
+[struct]: structs.html
+
 These two will not be equal, even if they have the same values:
 
-```{rust}
+```rust
 # struct Color(i32, i32, i32);
 # struct Point(i32, i32, i32);
 let black = Color(0, 0, 0);
@@ -20,7 +24,7 @@ let origin = Point(0, 0, 0);
 It is almost always better to use a struct than a tuple struct. We would write
 `Color` and `Point` like this instead:
 
-```{rust}
+```rust
 struct Color {
     red: i32,
     blue: i32,
@@ -37,12 +41,12 @@ struct Point {
 Now, we have actual names, rather than positions. Good names are important,
 and with a struct, we have actual names.
 
-There _is_ one case when a tuple struct is very useful, though, and that's a
-tuple struct with only one element. We call this the *newtype* pattern, because
+There _is_ one case when a tuple struct is very useful, though, and that’s a
+tuple struct with only one element. We call this the ‘newtype’ pattern, because
 it allows you to create a new type, distinct from that of its contained value
 and expressing its own semantic meaning:
 
-```{rust}
+```rust
 struct Inches(i32);
 
 let length = Inches(10);
@@ -52,5 +56,5 @@ println!("length is {} inches", integer_length);
 ```
 
 As you can see here, you can extract the inner integer type through a
-destructuring `let`, as we discussed previously in 'tuples.' In this case, the
+destructuring `let`, as we discussed previously in ‘tuples’. In this case, the
 `let Inches(integer_length)` assigns `10` to `integer_length`.