Am 05/12/14 um 14:15 schrieb Nathan Sizemore:
>
> If you're wanting to do comparisons, you will probably want to place a
> trait constraint on your functions from the following
> module: http://doc.rust-lang.org/std/cmp/index.html#traits
>
I tried to write the function (my second Rust code ever). I thought that
returning T makes no sense since the inverse of an integer should be a
float.
Is this the right way?
use std::num;
fn main() {
fn inverse<T: num::NumCast>(x: T) -> Result<f64, String> {
let local: f64 = num::cast(x).unwrap();
if 0f64 == local { return Err("x cannot be zero!".to_string()); }
Ok(1f64 / local)
}
match inverse(5.2f32) {
Ok(n) => println!("{}", n),
Err(s) => println!("{}", s)
}
match inverse(4i) {
Ok(n) => println!("{}", n),
Err(s) => println!("{}", s)
}
}
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