std/sys_common/
mod.rs

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1//! Platform-independent platform abstraction
2//!
3//! This is the platform-independent portion of the standard library's
4//! platform abstraction layer, whereas `std::sys` is the
5//! platform-specific portion.
6//!
7//! The relationship between `std::sys_common`, `std::sys` and the
8//! rest of `std` is complex, with dependencies going in all
9//! directions: `std` depending on `sys_common`, `sys_common`
10//! depending on `sys`, and `sys` depending on `sys_common` and `std`.
11//! This is because `sys_common` not only contains platform-independent code,
12//! but also code that is shared between the different platforms in `sys`.
13//! Ideally all that shared code should be moved to `sys::common`,
14//! and the dependencies between `std`, `sys_common` and `sys` all would form a dag.
15//! Progress on this is tracked in #84187.
16
17#![allow(missing_docs)]
18#![allow(missing_debug_implementations)]
19
20#[cfg(test)]
21mod tests;
22
23pub mod process;
24pub mod wstr;
25pub mod wtf8;
26
27// common error constructors
28
29/// A trait for viewing representations from std types
30#[doc(hidden)]
31#[allow(dead_code)] // not used on all platforms
32pub trait AsInner<Inner: ?Sized> {
33    fn as_inner(&self) -> &Inner;
34}
35
36/// A trait for viewing representations from std types
37#[doc(hidden)]
38#[allow(dead_code)] // not used on all platforms
39pub trait AsInnerMut<Inner: ?Sized> {
40    fn as_inner_mut(&mut self) -> &mut Inner;
41}
42
43/// A trait for extracting representations from std types
44#[doc(hidden)]
45pub trait IntoInner<Inner> {
46    fn into_inner(self) -> Inner;
47}
48
49/// A trait for creating std types from internal representations
50#[doc(hidden)]
51pub trait FromInner<Inner> {
52    fn from_inner(inner: Inner) -> Self;
53}
54
55// Computes (value*numer)/denom without overflow, as long as both
56// (numer*denom) and the overall result fit into i64 (which is the case
57// for our time conversions).
58#[allow(dead_code)] // not used on all platforms
59pub fn mul_div_u64(value: u64, numer: u64, denom: u64) -> u64 {
60    let q = value / denom;
61    let r = value % denom;
62    // Decompose value as (value/denom*denom + value%denom),
63    // substitute into (value*numer)/denom and simplify.
64    // r < denom, so (denom*numer) is the upper bound of (r*numer)
65    q * numer + r * numer / denom
66}
67
68pub fn ignore_notfound<T>(result: crate::io::Result<T>) -> crate::io::Result<()> {
69    match result {
70        Err(err) if err.kind() == crate::io::ErrorKind::NotFound => Ok(()),
71        Ok(_) => Ok(()),
72        Err(err) => Err(err),
73    }
74}
std/sys_common/mod.rs

std/sys_common/
mod.rs
