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Type Alias

A type alias defines a new name for an existing type. Type aliases are declared with the keyword type.

1. Improving Readability

Type aliases can make complex types easier to read and understand.

2. Enhancing Maintainability

Type aliases can help centralize the definition of a type, making it easier to update the type across the codebase.

Point to remember

The first letter of the type should be in upper case and follow UpperCamelCase.

// type alias

type Bannertype = u32;

fn main() {
    let mut id: Bannertype = 91615214;
    println!("{id}");
    id = 91615200;
    println!("{id}");
}

Example 2: Adding Semantic Meaning

type Kilometers = i32;
type Meters = i32;

fn calculate_distance(distance: Kilometers) -> Meters {
    distance * 1000
}

fn main() {
    let distance: Kilometers = 5;
    let distance_in_meters: Meters = calculate_distance(distance);
    println!("Distance in meters: {}", distance_in_meters);
}

Type aliases do not create distinct types.

The following is valid because both are i32:

let x: Kilometers = 5;
let y: Meters = x;

#typealias #alias #semanticVer 2.0.12