mod identities
{
    use std::ops::{Add};

    pub trait AdditiveIdentity<_AdditiveIdentity = Self> where
        Self: Sized + Add<_AdditiveIdentity, Output = Self>,
        _AdditiveIdentity: Sized + Add<Self, Output = Self>
    {
        const ADDITIVE_IDENTITY: _AdditiveIdentity;
    }

    impl AdditiveIdentity for i32
    {
        const ADDITIVE_IDENTITY: Self = 0;
    }

    impl AdditiveIdentity for f64
    {
        const ADDITIVE_IDENTITY: Self = 0.0;
    }
}

mod vector
{
    use crate::identities::{AdditiveIdentity};

    pub struct Vector<T>
    {
        pub components: T
    }

    impl<T> Vector<T> where T: AdditiveIdentity {
       pub const ZERO_VECTOR: Vector<[T; 3]> = Vector{components: [ T::ADDITIVE_IDENTITY,  T::ADDITIVE_IDENTITY,  T::ADDITIVE_IDENTITY]};
    }
}

fn main() {
    println!("Hello, world!");
}