In Rust, what trait do I need to compare a generic to an integer

Question

How can I compare the result of a calculation to a generic? T is always some unsigned integer type(u64, u32, etc), so the in the snippet should work, but how can i convince the rust-compiler?

fn reproduction<T>(val: T) -> bool
where
    T: PartialOrd
{
    let var_of_type_integer = 7; // actually the result of a calculation
    if val < var_of_type_integer { // ERROR: expected type parameter, found integer
        return true;
    }
    false
}

Answer 1

The PartialOrd trait can take a generic parameter to specify what type it can be compared against:

pub trait PartialOrd<Rhs = Self>: PartialEq<Rhs>
where
    Rhs: ?Sized,
{
    // ...
}

So this compiles:

pub fn reproduction<T>(val: T) -> bool
where
    T: PartialOrd<i32>,
{
    let var_of_type_integer = 7;
    if val < var_of_type_integer {
        return true;
    }
    false
}

Being able to compile if of course only half of the story. When you or users actually call the function with value of some concrete type, that type has to satisfy the specified PartialOrd<i32> trait bound.