ward

This crate exports two macros, which are intended to replicate the functionality of Swift's guard expression with Option<T>.

The guard! macro was created to emulate the guard let statement in Swift. This macro is only really useful for moving values out of Option<T>s into variables. The ward! macro, on the other hand, doesn't force the creation of a variable, it only returns the value that the guard! variable would place into a variable. As such, it's a more flexible version of the guard! macro; and probably also somewhat more Rustic.

Examples

```rust let sut = Some("test");

// This creates the variable res, which from an Option will return a T if it is Some(T), and will // otherwise return early from the function. guard!(let res = sut); assert_eq!(res, "test"); ```

The ward! macro, by comparison, just returns the value, without forcing you to make a variable from it (although we still do in this example):

rust let sut = Some("test"); let res = ward!(sut); assert_eq!(res, "test");

Both macros also support an else branch, which will run if the Option<T> is None:

```rust let sut = None; guard!(let _res = sut, else { println!("This will be called!");

// Because sut is None, the else branch will be run. When the else branch is invoked, guard!
// no longer automatically returns early for you, so you must do so yourself if you want it.
return;

}); unreachable!(); ```

Both macros also support an alternative "early return statement", which will let you e.g. break within loops:

rust // Not that you couldn't (and probably should) do this case with `while let Some(res) = sut`... let mut sut = Some(0); loop { let res = ward!(sut, break); sut = if res < 5 { Some(res + 1) } else { None } } assert_eq!(sut, None);