How to Use Trait Aliases in Rust

Rust does not support trait aliases; you must use type aliases for types or implement the trait directly on your struct. Use the type keyword to create a synonym for a complex type that implements a trait, then use that alias where needed.

use std::fmt::Display;

struct MyStruct;

impl Display for MyStruct {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "Hello")
    }
}

type MyDisplayAlias = MyStruct;

fn main() {
    let s: MyDisplayAlias = MyStruct;
    println!("{}", s);
}

Note: If you need to alias a trait itself (e.g., trait MyTrait = Display + Clone), this is not possible in stable Rust yet; you must list the traits explicitly in bounds or use a macro.

You cannot create a shortcut name for a trait in Rust like you can for a type. Instead, you create a shortcut for the specific data type that uses the trait. Think of it like having a nickname for a person (the type) rather than a nickname for the job they do (the trait).