如何在锈中声明可比较材料的通用矢量

Question

How can I define a vector of comparable in Rust?

Say, i32 , i16 ...

I tried arr: Vec<Ord> but the compiler complains about the trait "std::cmp::Ord" cannot be made into an object

Basically I need to store a vector of a vector of comparable objects. eg

    struct Setup<T: Ord + Copy> {
        arr: Vec<Vec<T>>
    }

    impl<T: Ord + Copy> Setup<T> {
        fn new() -> Self {
            Self {
                arr: vec![
                    vec![1, 2, 3, 4, 5],
                    vec![1.0, 2.0, 3.0]
                ]
            }
        }
    }

Instead of letting the consumer decide what exactly the type is, I would like they can get a vector of comparable stuffs.

Answer 1

The type Vec<Ord> would be a Vec where each item is a trait object. What you'd want to do is do Vec<T> and then set the trait bound on T to be : Ord , eg

struct Foo<T: Ord> {
  arr: Vec<T>,
}