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    // Copyright 2018 Developers of the Rand project.
    //
    // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
    // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
    // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
    // option. This file may not be copied, modified, or distributed
    // except according to those terms.

    //! The triangular distribution.
    #![allow(deprecated)]

    use crate::Rng;
    use crate::distributions::{Distribution, Standard};

    /// The triangular distribution.
    #[deprecated(since="0.7.0", note="moved to rand_distr crate")]
    #[derive(Clone, Copy, Debug)]
    pub struct Triangular {
        min: f64,
        max: f64,
        mode: f64,
    }

    impl Triangular {
        /// Construct a new `Triangular` with minimum `min`, maximum `max` and mode
        /// `mode`.
        ///
        /// # Panics
        ///
        /// If `max < mode`, `mode < max` or `max == min`.
        ///
        #[inline]
        pub fn new(min: f64, max: f64, mode: f64) -> Triangular {
            assert!(max >= mode);
            assert!(mode >= min);
            assert!(max != min);
            Triangular { min, max, mode }
        }
    }

    impl Distribution<f64> for Triangular {
        #[inline]
        fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> f64 {
            let f: f64 = rng.sample(Standard);
            let diff_mode_min = self.mode - self.min;
            let diff_max_min = self.max - self.min;
            if f * diff_max_min < diff_mode_min {
                self.min + (f * diff_max_min * diff_mode_min).sqrt()
            } else {
                self.max - ((1. - f) * diff_max_min * (self.max - self.mode)).sqrt()
            }
        }
    }

    #[cfg(test)]
    mod test {
        use crate::distributions::Distribution;
        use super::Triangular;

        #[test]
        fn test_new() {
            for &(min, max, mode) in &[
                (-1., 1., 0.), (1., 2., 1.), (5., 25., 25.), (1e-5, 1e5, 1e-3),
                (0., 1., 0.9), (-4., -0.5, -2.), (-13.039, 8.41, 1.17),
            ] {
                println!("{} {} {}", min, max, mode);
                let _ = Triangular::new(min, max, mode);
            }
        }

        #[test]
        fn test_sample() {
            let norm = Triangular::new(0., 1., 0.5);
            let mut rng = crate::test::rng(1);
            for _ in 0..1000 {
                norm.sample(&mut rng);
            }
        }
    }

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