Use the trait NumberAs in the current scope to let all primitive number types have a number_as method.
use number_as::NumberAs;
let a: i32 = 2u16.number_as();
assert_eq!(2i32, a);
assert_eq!(2i32, 2u16.number_as());
assert_eq!(20i32, 20.6.number_as());All implements for the NumberAs trait can be considered as a whole Primitive Number. If you want to design an add function, which accepts all kinds of primitive numbers,
you can use the Number trait as a trait bound.
use number_as::{Number, NumberAs};
fn add<T, J, K>(a: T, b: J) -> K where T: Number, J: Number, K: Number, i128: NumberAs<K> {
let a: i128 = a.number_as();
let b: i128 = b.number_as();
let c = a + b;
c.number_as()
}
assert_eq!(40i32, add(5u8, 35i16));