Make code work

Author: arora-aman

src/types/closure.md

@@ -385,14 +385,16 @@ If a closure captures a field of a composite types such as structs, tuples, and
 ### box-mut
 
 ```rust
+struct Foo { x: i32 }
+
 fn box_mut() {
     let mut s = Foo { x: 0 } ;
 
     let px = &mut s;
     let bx = Box::new(px);
 
 
-    let c = #[rustc_capture_analysis] move || bx.x += 10;
+    let c = move || bx.x += 10;
     // Mutable reference to this place:
     //   (*(*bx)).x
     //    ^ ^
@@ -401,7 +403,8 @@ fn box_mut() {
 }
 ```
 
-```
+<!-- ignore: Omit error about unterminated string literal when reprenting c_prime -->
+```ignore
 Closure mode = move
 C = {
     (ref mut, (*(*bx)).x)
@@ -434,7 +437,8 @@ fn main() {
 }
 ```
 
-```
+<!-- ignore: Omit error about unterminated string literal when reprenting c_prime -->
+```ignore
 Closure mode = ref
 C = {
     (ref mut, packed)
@@ -443,7 +447,7 @@ C' = C
 ```
 
 ### Optimization-Edge-Case
-```rust
+```edition2021
 struct Int(i32);
 struct B<'a>(&'a i32);
 
@@ -459,7 +463,8 @@ fn foo<'a, 'b>(m: &'a MyStruct<'b>) -> impl FnMut() + 'static {
 
 ```
 
-```
+<!-- ignore: Omit error about unterminated string literal when reprenting c_prime -->
+```ignore
 Closure mode = ref
 C = {
     (ref mut, *m.a)