[patterns]: patterns.html
-One of the many advantages of `match` is it enforces ‘exhaustiveness checking’.
-For example if we remove the last arm with the underscore `_`, the compiler will
+One of the many advantages of `match` is it enforces ‘exhaustiveness checking’.
+For example if we remove the last arm with the underscore `_`, the compiler will
give us an error:
```text
error: non-exhaustive patterns: `_` not covered
```
-Rust is telling us that we forgot a value. The compiler infers from `x` that it
-can have any positive 32bit value; for example 1 to 2,147,483,647. The `_` acts
+Rust is telling us that we forgot some value. The compiler infers from `x` that it
+can have any 32bit integer value; for example -2,147,483,648 to 2,147,483,647. The `_` acts
as a 'catch-all', and will catch all possible values that *aren't* specified in
-an arm of `match`. As you can see with the previous example, we provide `match`
+an arm of `match`. As you can see in the previous example, we provide `match`
arms for integers 1-5, if `x` is 6 or any other value, then it is caught by `_`.
`match` is also an expression, which means we can use it on the right-hand
};
```
-Sometimes it’s a nice way of converting something from one type to another; in
+Sometimes it’s a nice way of converting something from one type to another; in
this example the integers are converted to `String`.
# Matching on enums
Again, the Rust compiler checks exhaustiveness, so it demands that you
have a match arm for every variant of the enum. If you leave one off, it
-will give you a compile-time error unless you use `_` or provide all possible
+will give you a compile-time error unless you use `_` or provide all possible
arms.
Unlike the previous uses of `match`, you can’t use the normal `if`