this code can not run

fn main() {
    let a = 2;
    let b = 3;
    println!("{}",sum1(&a,&b));
  }
fn sum1<T:std::ops::Add<Output = T>>(a:&T,b:&T)->T{
  a + b
}

use (a:T,b:T) can run,and the following code can run too

fn main() {
    let a = 2;
    let b = 3;
    println!("{}",sum1(&a,&b));
}
  
fn sum1(a:&i32,b:&i32)->T{
  a + b
}