Supertraits

Rust doesn't have "inheritance", but you can define a trait as being a superset of another trait. For example:

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trait Person {
    fn name(&self) -> String;
}
// Person is a supertrait of Student.
// Implementing Student requires you to also impl Person.
trait Student: Person {
    fn university(&self) -> String;
}
trait Programmer {
    fn fav_language(&self) -> String;
}
// CompSciStudent (computer science student) is a subtrait of both Programmer 
// and Student. Implementing CompSciStudent requires you to impl both supertraits.
trait CompSciStudent: Programmer + Student {
    fn git_username(&self) -> String;
}
fn comp_sci_student_greeting(student: &dyn CompSciStudent) -> String {
    format!(
        "My name is {} and I attend {}. My favorite language is {}. My Git username is {}",
        student.name(),
        student.university(),
        student.fav_language(),
        student.git_username()
    )
}
fn main() {}
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See also:

The Rust Programming Language chapter on supertraits