A few use cases: let foobar = Default::default(); do_something_with(foobar); // where do_something_with takes a FooBar param One I often use in unit t

A few use cases: let foobar = Default::default(); do_something_with(foobar); // where do_something_with takes a FooBar param One I often use in unit tests: fn generate_ids<const N: usize>() -> [Id; N] { ... } let [id_button, id_label, id_thing, id_other_thing] = generate_ids(); (before const generics were stabilized, the above code instead had multiple utility functions, eg generate_2_ids, generate_3_ids, etc)