Changed invalid coersion examples

Author: AloeareV

src/type-coercions.md

@@ -15,10 +15,10 @@ sites are:
 
 * `let` statements where an explicit type is given.
 
-   For example, `42` is coerced to have type `i8` in the following:
+   For example, `&mut 42` is coerced to have type `&i8` in the following:
 
    ```rust
-   let _: i8 = 42;
+   let _: &i8 = &mut 42;
    ```
 
 * `static` and `const` items (similar to `let` statements).
@@ -28,13 +28,13 @@ sites are:
   The value being coerced is the actual parameter, and it is coerced to
   the type of the formal parameter.
 
-  For example, `42` is coerced to have type `i8` in the following:
+  For example, `&mut 42` is coerced to have type `&i8` in the following:
 
   ```rust
-  fn bar(_: i8) { }
+  fn bar(_: &i8) { }
 
   fn main() {
-      bar(42);
+      bar(&mut 42);
   }
   ```
 
@@ -43,26 +43,29 @@ sites are:
 
 * Instantiations of struct, union, or enum variant fields
 
-  For example, `42` is coerced to have type `i8` in the following:
+  For example, `&mut 42` is coerced to have type `&i8` in the following:
 
   ```rust
-  struct Foo { x: i8 }
+  struct Foo { x: &i8 }
 
   fn main() {
-      Foo { x: 42 };
+      Foo { x: &mut 42 };
   }
   ```
 
-* Function results – either the final line of a block if it is not
+* Function results–either the final line of a block if it is not
   semicolon-terminated or any expression in a `return` statement
 
-  For example, `42` is coerced to have type `i8` in the following:
+  For example, `x` is coerced to have type `&dyn Binary` in the following:
 
   ```rust
-  fn foo() -> i8 {
-      42
+  fn foo(x: &u32) -> &dyn Binary {
+      x
   }
   ```
+The [as] keyword can also be used to perform explicit type coersion, as well as
+some additional casts.
+
 
 If the expression in one of these coercion sites is a coercion-propagating
 expression, then the relevant sub-expressions in that expression are also
@@ -183,6 +186,7 @@ unsized coercion to `Foo<U>`.
 
 [RFC 401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md
 [RFC 1558]: https://github.com/rust-lang/rfcs/blob/master/text/1558-closure-to-fn-coercion.md
-[subtype]: subtyping.html
+[subtype]: subtyping.html`
+[as]: operator-expr.html#type-cast-expressions`
 [`Unsize`]: ../std/marker/trait.Unsize.html
 [`CoerceUnsized`]: ../std/ops/trait.CoerceUnsized.html