rand/distributions/
weighted.rs

1// Copyright 2018 Developers of the Rand project.
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9//! Weighted index sampling
10//!
11//! This module is deprecated. Use [`crate::distributions::WeightedIndex`] and
12//! [`crate::distributions::WeightedError`] instead.
13
14pub use super::{WeightedIndex, WeightedError};
15
16#[allow(missing_docs)]
17#[deprecated(since = "0.8.0", note = "moved to rand_distr crate")]
18pub mod alias_method {
19    // This module exists to provide a deprecation warning which minimises
20    // compile errors, but still fails to compile if ever used.
21    use core::marker::PhantomData;
22    use alloc::vec::Vec;
23    use super::WeightedError;
24
25    #[derive(Debug)]
26    pub struct WeightedIndex<W: Weight> {
27        _phantom: PhantomData<W>,
28    }
29    impl<W: Weight> WeightedIndex<W> {
30        pub fn new(_weights: Vec<W>) -> Result<Self, WeightedError> {
31            Err(WeightedError::NoItem)
32        }
33    }
34
35    pub trait Weight {}
36    macro_rules! impl_weight {
37        () => {};
38        ($T:ident, $($more:ident,)*) => {
39            impl Weight for $T {}
40            impl_weight!($($more,)*);
41        };
42    }
43    impl_weight!(f64, f32,);
44    impl_weight!(u8, u16, u32, u64, usize,);
45    impl_weight!(i8, i16, i32, i64, isize,);
46    #[cfg(not(target_os = "emscripten"))]
47    impl_weight!(u128, i128,);
48}