mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-17 19:14:16 +00:00
20 lines
425 B
Rust
20 lines
425 B
Rust
//@ run-pass
|
|
pub trait NumCast: Sized {
|
|
fn from(i: i32) -> Option<Self>;
|
|
}
|
|
|
|
pub trait NumExt: PartialEq + PartialOrd + NumCast {}
|
|
|
|
impl NumExt for f32 {}
|
|
impl NumCast for f32 {
|
|
fn from(i: i32) -> Option<f32> { Some(i as f32) }
|
|
}
|
|
|
|
fn num_eq_one<T: NumExt>(n: T) {
|
|
println!("{}", n == NumCast::from(1).unwrap())
|
|
}
|
|
|
|
pub fn main() {
|
|
num_eq_one(1f32); // you need to actually use the function to trigger the ICE
|
|
}
|