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// 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;
}

impl ApproxEq<f32> for f32 {
  #[inline]
  fn approx_epsilon() -> f32 { 1.0e-6 }

  #[inline]
  fn approx_eq(&self, other: &f32) -> bool {
    self.approx_eq_eps(other, &1.0e-6)
  }

  #[inline]
  fn approx_eq_eps(&self, other: &f32, approx_epsilon: &f32) -> bool {
    (*self - *other).abs() < *approx_epsilon
  }
}


impl ApproxEq<f64> for f64 {
  #[inline]
  fn approx_epsilon() -> f64 { 1.0e-6 }

  #[inline]
  fn approx_eq(&self, other: &f64) -> bool {
    self.approx_eq_eps(other, &1.0e-6)
  }
    
  #[inline]
  fn approx_eq_eps(&self, other: &f64, approx_epsilon: &f64) -> bool {
    (*self - *other).abs() < *approx_epsilon
  }
}