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use quickcheck::{Arbitrary, Gen, StdGen};
use std::ops::Deref;
#[derive(Copy, Clone, Debug)]
/// quickcheck Arbitrary adaptor - half the size of `T` on average
pub struct Small<T>(pub T);
impl<T> Deref for Small<T> {
type Target = T;
fn deref(&self) -> &T {
&self.0
}
}
impl<T> Arbitrary for Small<T>
where
T: Arbitrary,
{
fn arbitrary<G: Gen>(g: &mut G) -> Self {
let sz = g.size() / 2;
Small(T::arbitrary(&mut StdGen::new(g, sz)))
}
fn shrink(&self) -> Box<dyn Iterator<Item = Self>> {
Box::new((**self).shrink().map(Small))
}
}
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