Rust Traits text

content/post/2024-09-21-RustTraits.md

@@ -15,7 +15,11 @@ This concept is interesting and I wanted to write it down as I learned it. I've
 the terminology wrong! 
 
 Traits can be added to types to allow them to do something, as if these were classes in C++ that already had methods 
-implemented. So if I want to check if an i32 is divisible by 7, I can add: 
+implemented. 
+
+In this scenario, I'm imagining that it's very importand to check if a number is divisible by seven, and if it actually is
+the number seven. I can add a function to the "i32" and "u32" object. I would probably need to do this to i64 too, but 
+this isn't particularly exciting to reiterate in code below.
 
 ```
 trait Sevens {
@@ -31,15 +35,6 @@ impl Sevens for i32 {
         7 == *self
     }
 }
-
-fn main() {
-    let x: i32 = 9;
-    let y: u32 = 49;
-    println!("Is {} divisible by 7? {}", x, x.divisible_by_seven());
-    println!("Is {} divisible by 7? {}", y, y.divisible_by_seven());
-    println!("Is {} equal to 7? {}", y, y.is_seven());
-    println!("Is {} equal to 7? {}", 7, 7.is_seven());
-}
 ```
 
 And if I want the same to work on u32, I can add this to the code: 
@@ -54,3 +49,20 @@ impl Sevens for u32 {
     }
 }
 ```
+
+And then main can be added (note, these are all in the same file at the moment as I haven't 
+imported another file with a "use" declaration.
+
+
+```
+fn main() {
+    let x: i32 = 9;
+    let y: u32 = 49;
+    println!("Is {} divisible by 7? {}", x, x.divisible_by_seven());
+    println!("Is {} divisible by 7? {}", y, y.divisible_by_seven());
+    println!("Is {} equal to 7? {}", y, y.is_seven());
+    println!("Is {} equal to 7? {}", 7, 7.is_seven());
+}
+```
+
+Ooh, notice I can now do `7.is_seven()`, isn't that interesting.