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use core::{i128, u128};
use core::{isize, usize, i16, i32, i64, i8, u16, u32, u64, u8};
use core::{f32, f64};
use core::num::Wrapping;

pub trait Bounded {
    fn min_value() -> Self;
    fn max_value() -> Self;
}

macro_rules! trait_bounded {
    ($T:ty, $min:expr, $max:expr) => {
        impl Bounded for $T {
            #[inline(always)]
            fn min_value() -> $T {$min}
            #[inline(always)]
            fn max_value() -> $T {$max}
        }
    }
}

trait_bounded!(usize, usize::MIN, usize::MAX);
trait_bounded!(u8, u8::MIN, u8::MAX);
trait_bounded!(u16, u16::MIN, u16::MAX);
trait_bounded!(u32, u32::MIN, u32::MAX);
trait_bounded!(u64, u64::MIN, u64::MAX);
trait_bounded!(u128, u128::MIN, u128::MAX);

trait_bounded!(isize, isize::MIN, isize::MAX);
trait_bounded!(i8, i8::MIN, i8::MAX);
trait_bounded!(i16, i16::MIN, i16::MAX);
trait_bounded!(i32, i32::MIN, i32::MAX);
trait_bounded!(i64, i64::MIN, i64::MAX);
trait_bounded!(i128, i128::MIN, i128::MAX);

trait_bounded!(f32, f32::MIN, f32::MAX);
trait_bounded!(f64, f64::MIN, f64::MAX);

impl<T> Bounded for Wrapping<T>
where
    T: Bounded,
{
    #[inline(always)]
    fn min_value() -> Self {
        Wrapping(T::min_value())
    }
    #[inline(always)]
    fn max_value() -> Self {
        Wrapping(T::max_value())
    }
}

#[cfg(test)]
mod test {
    use core::{isize, usize, f32, f64};
    use super::Bounded;

    fn min_value<T: Bounded>() -> T {
        T::min_value()
    }
    fn max_value<T: Bounded>() -> T {
        T::max_value()
    }

    #[test]
    fn test_bounded() {
        assert_eq!(min_value::<usize>(), usize::MIN);
        assert_eq!(min_value::<f32>(), f32::MIN);
        assert_eq!(max_value::<f64>(), f64::MAX);
        assert_eq!(max_value::<isize>(), isize::MAX);
    }
}