| // Copyright 2013 The Servo Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| /// Trait for testing approximate equality |
| pub trait ApproxEq<Eps> { |
| fn approx_epsilon() -> Eps; |
| fn approx_eq(&self, other: &Self) -> bool; |
| fn approx_eq_eps(&self, other: &Self, approx_epsilon: &Eps) -> bool; |
| } |
| |
| macro_rules! approx_eq { |
| ($ty:ty, $eps:expr) => { |
| impl ApproxEq<$ty> for $ty { |
| #[inline] |
| fn approx_epsilon() -> $ty { |
| $eps |
| } |
| #[inline] |
| fn approx_eq(&self, other: &$ty) -> bool { |
| self.approx_eq_eps(other, &$eps) |
| } |
| #[inline] |
| fn approx_eq_eps(&self, other: &$ty, approx_epsilon: &$ty) -> bool { |
| num_traits::Float::abs(*self - *other) < *approx_epsilon |
| } |
| } |
| }; |
| } |
| |
| approx_eq!(f32, 1.0e-6); |
| approx_eq!(f64, 1.0e-6); |
