異なる引数のトレイトを取る Verifier トレイト

different_type_arg_trait.rs

use std::ops::{Add, Index};
use std::cmp::Eq;
use std::marker::PhantomData;
 
pub trait Trait<T> {
    fn verify(&self, a: T, b: T) -> bool;
}

pub struct VerifierX<T: Add + Eq> {
    a: T,
}

impl<T: Add<Output=T> + Eq> Trait<T> for VerifierX<T> {
    fn verify(&self, a: T, b: T) -> bool {
        if self.a == a + b { return true; }
        false
    }
}

pub struct VerifierY<T: Index<usize, Output=U>, U: Eq>(PhantomData<(T,U)>);

impl<T, U> Trait<T> for VerifierY<T, U> where T: Index<usize, Output=U>, U: Eq {
    fn verify(&self, a: T, b: T) -> bool {
        if a[0] == b[0] { return true; }
        false
    }
}


fn main() {
    let v = VerifierX{a: 10};
    println!("{}, {}",v.verify(1,9), v.verify(1,5));
    
    let v = VerifierY::<Vec<i32>,i32>(PhantomData);
    println!("{}, {}", v.verify(vec!{1,2},vec!{1,3}),
                    v.verify(vec!{1,3}, vec!{0,3}));
}