Structs
Like tuples, Struct can also be destructured by matching:
struct Foo { x: (u32, u32), y: u32, } #[rustfmt::skip] fn main() { let foo = Foo { x: (1, 2), y: 3 }; match foo { Foo { x: (1, b), y } => println!("x.0 = 1, b = {b}, y = {y}"), Foo { y: 2, x: i } => println!("y = 2, x = {i:?}"), Foo { y, .. } => println!("y = {y}, other fields were ignored"), } }
This slide should take about 4 minutes.
- Change the literal values in
foo
to match with the other patterns. - Add a new field to
Foo
and make changes to the pattern as needed. - The distinction between a capture and a constant expression can be hard to spot. Try changing the
2
in the second arm to a variable, and see that it subtly doesn't work. Change it to aconst
and see it working again.