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Rust / Blanket Implementation

By using generic parameters, you can impl a trait for any type that satisfies some trait bounds, for example, implement trait ToString for every type T that implemented the Display trait:

impl<T: Display> ToString for T {
    ...
}

This technique is called blanket implementation. It’s being used widely in Rust standard library.

You can even omit the trait bound to implement your trait for every type:

mod foo {
    pub trait Foo {
        fn bar(&self) {
            println!("Foo::Barrrrrr!!!");
        }
    }
    impl<T> Foo for T {}
}
 
use foo::Foo;
 
let i = 10i32;
i.bar();