Type aliases - The Rust Reference

# Type aliases

> Syntax
> TypeAlias :
> `type` IDENTIFIER Generics? WhereClause? `=` Type `;`

A type alias defines a new name for an existing type. Type aliases are declared with the keyword `type`. Every value has a single, specific type, but may implement several different traits, or be compatible with several different type constraints.

For example, the following defines the type `Point` as a synonym for the type `(u8, u8)`, the type of pairs of unsigned 8 bit integers:

    # #![allow(unused_variables)]
    #fn main() {
    type Point = (u8, u8);
    let p: Point = (41, 68);
    #}

A type alias to an enum type cannot be used to qualify the constructors:

    # #![allow(unused_variables)]
    #fn main() {
    enum E { A }
    type F = E;
    let _: F = E::A;  // OK
    // let _: F = F::A;  // Doesn't work
    #}