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    use std::cell::Cell;

    /// Fast random number generate
    ///
    /// Implement xorshift64+: 2 32-bit xorshift sequences added together.
    /// Shift triplet [17,7,16] was calculated as indicated in Marsaglia's
    /// Xorshift paper: https://www.jstatsoft.org/article/view/v008i14/xorshift.pdf
    /// This generator passes the SmallCrush suite, part of TestU01 framework:
    /// http://simul.iro.umontreal.ca/testu01/tu01.html
    #[derive(Debug)]
    pub(crate) struct FastRand {
        one: Cell<u32>,
        two: Cell<u32>,
    }

    impl FastRand {
        /// Initialize a new, thread-local, fast random number generator.
        pub(crate) fn new(seed: u64) -> FastRand {
            let one = (seed >> 32) as u32;
            let mut two = seed as u32;

            if two == 0 {
                // This value cannot be zero
                two = 1;
            }

            FastRand {
                one: Cell::new(one),
                two: Cell::new(two),
            }
        }

        pub(crate) fn fastrand_n(&self, n: u32) -> u32 {
            // This is similar to fastrand() % n, but faster.
            // See https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction/
            let mul = (self.fastrand() as u64).wrapping_mul(n as u64);
            (mul >> 32) as u32
        }

        fn fastrand(&self) -> u32 {
            let mut s1 = self.one.get();
            let s0 = self.two.get();

            s1 ^= s1 << 17;
            s1 = s1 ^ s0 ^ s1 >> 7 ^ s0 >> 16;

            self.one.set(s0);
            self.two.set(s1);

            s0.wrapping_add(s1)
        }
    }

    // Used by the select macro and `StreamMap`
    #[cfg(any(feature = "macros"))]
    #[doc(hidden)]
    #[cfg_attr(not(feature = "macros"), allow(unreachable_pub))]
    pub fn thread_rng_n(n: u32) -> u32 {
        thread_local! {
            static THREAD_RNG: FastRand = FastRand::new(crate::loom::rand::seed());
        }

        THREAD_RNG.with(|rng| rng.fastrand_n(n))
    }