rand04_compat/src/lib.rs

64 lines
1.4 KiB
Rust

//! # Wrappers for compatibility with rand 0.4
#![no_std]
use core::marker::PhantomData;
use rand::Rng;
pub use rand04;
#[derive(Debug)]
pub struct Generator<'a, T, R>(&'a mut R, PhantomData<T>);
impl<'a, R: Rng, T: rand04::Rand> Iterator for Generator<'a, T, R> {
type Item = T;
fn next(&mut self) -> Option<T> {
Some(self.0.gen04())
}
}
/// An extension trait for `Rng` to generate values that implement `rand04::Rand`.
pub trait RngExt {
/// Returns a random value.
fn gen04<T: rand04::Rand>(&mut self) -> T;
/// Returns an iterator that will yield an infinite number of randomly generated items.
fn gen_iter04<T: rand04::Rand>(&mut self) -> Generator<T, Self>
where
Self: Sized;
}
impl<R: Rng + ?Sized> RngExt for R {
fn gen04<T: rand04::Rand>(&mut self) -> T {
rand04::Rng::gen(&mut RngWrapper(self))
}
fn gen_iter04<T: rand04::Rand>(&mut self) -> Generator<T, Self>
where
Self: Sized,
{
Generator(self, PhantomData)
}
}
/// A wrapper for a random number generator that implements the 0.4 `Rng` trait.
pub struct RngWrapper<R>(pub R);
impl<R: Rng> rand04::Rng for RngWrapper<R> {
#[inline]
fn next_u32(&mut self) -> u32 {
self.0.next_u32()
}
#[inline]
fn next_u64(&mut self) -> u64 {
self.0.next_u64()
}
#[inline]
fn fill_bytes(&mut self, dest: &mut [u8]) {
self.0.fill_bytes(dest)
}
}