Error code E0639
This error indicates that the struct, enum or enum variant cannot be
instantiated from outside of the defining crate as it has been marked
as non_exhaustive
and as such more fields/variants may be added in
future that could cause adverse side effects for this code.
Erroneous code example:
#[non_exhaustive]
pub struct NormalStruct {
pub first_field: u16,
pub second_field: u16,
}
let ns = NormalStruct { first_field: 640, second_field: 480 }; // error!
It is recommended that you look for a new
function or equivalent in the
crate's documentation.