Updated struct and enums in pattern-matching. (#2021)

#1464 issue.

---------

Co-authored-by: Martin Geisler <martin@geisler.net>

src/SUMMARY.md

@@ -76,7 +76,8 @@
 - [Welcome](welcome-day-2.md)
 - [Pattern Matching](pattern-matching.md)
   - [Matching Values](pattern-matching/match.md)
-  - [Destructuring](pattern-matching/destructuring.md)
+  - [Destructuring Structs](pattern-matching/destructuring-structs.md)
+  - [Destructuring Enums](pattern-matching/destructuring-enums.md)
   - [Let Control Flow](pattern-matching/let-control-flow.md)
   - [Exercise: Expression Evaluation](pattern-matching/exercise.md)
     - [Solution](pattern-matching/solution.md)

src/pattern-matching/destructuring-enums.md

@@ -1,18 +1,10 @@
 ---
-minutes: 8
+minutes: 4
 ---
 
-# Destructuring
+# Enums
 
-Like tuples, structs and enums can also be destructured by matching:
-
-## Structs
-
-```rust,editable
-{{#include ../../third_party/rust-by-example/destructuring-structs.rs}}
-```
-
-## Enums
+Like tuples, enums can also be destructured by matching:
 
 Patterns can also be used to bind variables to parts of your values. This is how
 you inspect the structure of your types. Let us start with a simple `enum` type:
@@ -46,18 +38,6 @@ arm, `half` is bound to the value inside the `Ok` variant. In the second arm,
 
 <details>
 
-# Structs
-
-- Change the literal values in `foo` to match with the other patterns.
-- Add a new field to `Foo` and make changes to the pattern as needed.
-- The distinction between a capture and a constant expression can be hard to
-  spot. Try changing the `2` in the second arm to a variable, and see that it
-  subtly doesn't work. Change it to a `const` and see it working again.
-
-# Enums
-
-Key points:
-
 - The `if`/`else` expression is returning an enum that is later unpacked with a
   `match`.
 - You can try adding a third variant to the enum definition and displaying the

src/pattern-matching/destructuring-structs.md

@@ -0,0 +1,21 @@
+---
+minutes: 4
+---
+
+# Structs
+
+Like tuples, Struct can also be destructured by matching:
+
+```rust,editable
+{{#include ../../third_party/rust-by-example/destructuring-structs.rs}}
+```
+
+<details>
+
+- Change the literal values in `foo` to match with the other patterns.
+- Add a new field to `Foo` and make changes to the pattern as needed.
+- The distinction between a capture and a constant expression can be hard to
+  spot. Try changing the `2` in the second arm to a variable, and see that it
+  subtly doesn't work. Change it to a `const` and see it working again.
+
+</details>