Rust Programming By Example

 Explaining the Some function

Generally, when a function expects an Option argument, it looks like this:

fn some_func(arg: Option<&str>) {
    // some code
}

And you call it as follows:

some_func(Some("ratatouille"));
some_func(None);

Now, what if I told you that you could get rid of the Some? Nice, right? Well, this is actually pretty easy:

fn some_func<'a, T: Into<Option<&'a str>>>(arg: T) {
    // some code
}

And you can now call it as follows:

some_func(Some("ratatouille")); // If you *really* like to write "Some"...
some_func("ratatouille");
some_func(None);

Better! However, to make users' lives easier, it'll require a bit more code for whoever's writing the function. You can't use arg as it is; you need to add an extra step. Before, you'd just ...