/*
Title: Enumeration of Constants in Rust
Example with and without explicit values
*/
#[derive(Debug)]
// Enum WITHOUT explicit values
// Rust automatically assigns no numeric values unless you use repr()
enum Color {
Red, // index-like position 0
Green, // 1
Blue, // 2
}
#[derive(Debug)]
// Enum WITH explicit values using repr() and manual assignment
#[repr(i32)]
enum Status {
OK = 1,
Warning = 5,
Error = 6,
Critical = 10,
}
fn main() {
println!("Enum without explicit values:");
println!("Red = {:?}", Color::Red);
println!("Green = {:?}", Color::Green);
println!("Blue = {:?}", Color::Blue);
println!("\nEnum with explicit values:");
println!("OK = {}", Status::OK as i32);
println!("Warning = {}", Status::Warning as i32);
println!("Error = {}", Status::Error as i32);
println!("Critical = {}", Status::Critical as i32);
}
/*
run:
Enum without explicit values:
Red = Red
Green = Green
Blue = Blue
Enum with explicit values:
OK = 1
Warning = 5
Error = 6
Critical = 10
*/
