14.3 Tuple struct

In tuple structs, the fields are not named but indexed.

As an example, here is a Color tuple struct that defines an RGB color on 8-bit values. The declaration uses parenthesis instead of curly braces:

:clear

struct Color(u8, u8, u8);

For defining an instance we use also parenthesis and specify the values in the order of definition:

let yellow = Color(0xff, 0xff, 0);

To access values from an instance, we use integer indices:

println!("red={}, green={}, blue={}", yellow.0, yellow.1, yellow.2);

red=255, green=255, blue=0