What are the differences between an impl trait argument and generic function parameter?

Question

impl Traits can be used as function arguments. Are there differences between this and a generic function with a trait constraint?

trait Foo {}

fn func1(_: i         


        

Answer 1

Both produce identical assembly, at least with the following simple test case:

trait Foo {}

struct Bar;

impl Foo for Bar {}

fn func1(_: impl Foo) {}

fn func2(_: T) {}

fn main() {
    let x = Bar;

    let y = func1(x); // or func2(x);
}