trait Foo { fn foo(&self); }
trait Bar { fn bar(&self); }

impl Foo for u32 {
    fn foo(&self) { println!("u32::foo"); }
}

impl Bar for u32 {
    fn bar(&self) { println!("u32::bar"); }
}

impl Foo for String {
    fn foo(&self) { println!("String::foo"); }
}

fn call_foo<T>(value: T) where T : Foo { value.foo() }
//fn call_bar<T: Foo>(value: T) { value.bar() }
//fn call_bar(value: Foo) { value.bar() } // not ok
//fn call_bar(value: impl Foo) { value.bar() }

fn main() {
    (1u32).bar();
    call_foo(1u32);
    call_foo("foo".to_string());
}