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 fs;
24pub mod process;
25pub mod wstr;
26pub mod wtf8;
27
28// common error constructors
29
30/// A trait for viewing representations from std types
31#[doc(hidden)]
32#[allow(dead_code)] // not used on all platforms
33pub trait AsInner<Inner: ?Sized> {
34    fn as_inner(&self) -> &Inner;
35}
36
37/// A trait for viewing representations from std types
38#[doc(hidden)]
39#[allow(dead_code)] // not used on all platforms
40pub trait AsInnerMut<Inner: ?Sized> {
41    fn as_inner_mut(&mut self) -> &mut Inner;
42}
43
44/// A trait for extracting representations from std types
45#[doc(hidden)]
46pub trait IntoInner<Inner> {
47    fn into_inner(self) -> Inner;
48}
49
50/// A trait for creating std types from internal representations
51#[doc(hidden)]
52pub trait FromInner<Inner> {
53    fn from_inner(inner: Inner) -> Self;
54}
55
56// Computes (value*numer)/denom without overflow, as long as both
57// (numer*denom) and the overall result fit into i64 (which is the case
58// for our time conversions).
59#[allow(dead_code)] // not used on all platforms
60pub fn mul_div_u64(value: u64, numer: u64, denom: u64) -> u64 {
61    let q = value / denom;
62    let r = value % denom;
63    // Decompose value as (value/denom*denom + value%denom),
64    // substitute into (value*numer)/denom and simplify.
65    // r < denom, so (denom*numer) is the upper bound of (r*numer)
66    q * numer + r * numer / denom
67}
68
69pub fn ignore_notfound<T>(result: crate::io::Result<T>) -> crate::io::Result<()> {
70    match result {
71        Err(err) if err.kind() == crate::io::ErrorKind::NotFound => Ok(()),
72        Ok(_) => Ok(()),
73        Err(err) => Err(err),
74    }
75}
std/sys_common/mod.rs

std/sys_common/
mod.rs
