nalgebra/src/base/helper.rs
2021-03-02 12:25:12 +01:00

32 lines
723 B
Rust

#[cfg(feature = "arbitrary")]
use quickcheck::{Arbitrary, Gen};
#[cfg(feature = "rand-no-std")]
use rand::{
distributions::{Distribution, Standard},
Rng,
};
/// Simple helper function for rejection sampling
#[cfg(feature = "arbitrary")]
#[doc(hidden)]
#[inline]
pub fn reject<F: FnMut(&T) -> bool, T: Arbitrary>(g: &mut Gen, f: F) -> T {
use std::iter;
iter::repeat(())
.map(|_| Arbitrary::arbitrary(g))
.find(f)
.unwrap()
}
#[doc(hidden)]
#[inline]
#[cfg(feature = "rand-no-std")]
pub fn reject_rand<G: Rng + ?Sized, F: FnMut(&T) -> bool, T>(g: &mut G, f: F) -> T
where
Standard: Distribution<T>,
{
use std::iter;
iter::repeat(()).map(|_| g.gen()).find(f).unwrap()
}