base/
types.rs

1// Copyright 2025 The ChromiumOS Authors
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Integer types.
6
7/// A positive integer in the range `0..=i32::MAX`.
8pub struct U31(u32);
9
10impl U31 {
11    pub const fn new(value: u32) -> Option<Self> {
12        if value > i32::MAX as _ {
13            None
14        } else {
15            Some(Self(value))
16        }
17    }
18}
19
20impl From<U31> for i32 {
21    fn from(value: U31) -> Self {
22        value.0 as _
23    }
24}
25
26/// A strictly negative integer in the range `i32::MIN..0`.
27pub struct NegativeI32(i32);
28
29impl NegativeI32 {
30    pub const fn new(value: i32) -> Option<Self> {
31        if value < 0 {
32            Some(Self(value))
33        } else {
34            None
35        }
36    }
37}
38
39impl From<NegativeI32> for i32 {
40    fn from(value: NegativeI32) -> Self {
41        value.0
42    }
43}
44
45/// Represent a `Result` as a single integer where negative values are errors.
46pub fn fold_into_i32<T, E>(result: Result<T, E>) -> i32
47where
48    T: Into<U31>,
49    E: Into<NegativeI32>,
50{
51    match result {
52        Ok(t) => i32::from(t.into()),
53        Err(e) => i32::from(e.into()),
54    }
55}
base/types.rs

base/
types.rs
