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    //! `rustix` provides efficient memory-safe and [I/O-safe] wrappers to
    //! POSIX-like, Unix-like, Linux, and Winsock2 syscall-like APIs, with
    //! configurable backends.
    //!
    //! With rustix, you can write code like this:
    //!
    //! ```rust
    //! # #[cfg(feature = "net")]
    //! # fn read(sock: std::net::TcpStream, buf: &mut [u8]) -> std::io::Result<()> {
    //! # use rustix::net::RecvFlags;
    //! let nread: usize = rustix::net::recv(&sock, buf, RecvFlags::PEEK)?;
    //! # let _ = nread;
    //! # Ok(())
    //! # }
    //! ```
    //!
    //! instead of like this:
    //!
    //! ```rust
    //! # #[cfg(feature = "net")]
    //! # fn read(sock: std::net::TcpStream, buf: &mut [u8]) -> std::io::Result<()> {
    //! # use std::convert::TryInto;
    //! # #[cfg(unix)]
    //! # use std::os::unix::io::AsRawFd;
    //! # #[cfg(target_os = "wasi")]
    //! # use std::os::wasi::io::AsRawFd;
    //! # #[cfg(windows)]
    //! # use windows_sys::Win32::Networking::WinSock as libc;
    //! # #[cfg(windows)]
    //! # use std::os::windows::io::AsRawSocket;
    //! # const MSG_PEEK: i32 = libc::MSG_PEEK;
    //! let nread: usize = unsafe {
    //!     #[cfg(any(unix, target_os = "wasi"))]
    //!     let raw = sock.as_raw_fd();
    //!     #[cfg(windows)]
    //!     let raw = sock.as_raw_socket();
    //!     match libc::recv(
    //!         raw as _,
    //!         buf.as_mut_ptr().cast(),
    //!         buf.len().try_into().unwrap_or(i32::MAX as _),
    //!         MSG_PEEK,
    //!     ) {
    //!         -1 => return Err(std::io::Error::last_os_error()),
    //!         nread => nread as usize,
    //!     }
    //! };
    //! # let _ = nread;
    //! # Ok(())
    //! # }
    //! ```
    //!
    //! rustix's APIs perform the following tasks:
    //!  - Error values are translated to [`Result`]s.
    //!  - Buffers are passed as Rust slices.
    //!  - Out-parameters are presented as return values.
    //!  - Path arguments use [`Arg`], so they accept any string type.
    //!  - File descriptors are passed and returned via [`AsFd`] and [`OwnedFd`]
    //!    instead of bare integers, ensuring I/O safety.
    //!  - Constants use `enum`s and [`bitflags`] types.
    //!  - Multiplexed functions (eg. `fcntl`, `ioctl`, etc.) are de-multiplexed.
    //!  - Variadic functions (eg. `openat`, etc.) are presented as non-variadic.
    //!  - Functions and types which need `l` prefixes or `64` suffixes to enable
    //!    large-file support are used automatically, and file sizes and offsets
    //!    are presented as `u64` and `i64`.
    //!  - Behaviors that depend on the sizes of C types like `long` are hidden.
    //!  - In some places, more human-friendly and less historical-accident names
    //!    are used (and documentation aliases are used so that the original names
    //!    can still be searched for).
    //!  - Provide y2038 compatibility, on platforms which support this.
    //!  - Correct selected platform bugs, such as behavioral differences when
    //!    running under seccomp.
    //!
    //! Things they don't do include:
    //!  - Detecting whether functions are supported at runtime.
    //!  - Hiding significant differences between platforms.
    //!  - Restricting ambient authorities.
    //!  - Imposing sandboxing features such as filesystem path or network address
    //!    sandboxing.
    //!
    //! See [`cap-std`], [`system-interface`], and [`io-streams`] for libraries
    //! which do hide significant differences between platforms, and [`cap-std`]
    //! which does perform sandboxing and restricts ambient authorities.
    //!
    //! [`cap-std`]: https://crates.io/crates/cap-std
    //! [`system-interface`]: https://crates.io/crates/system-interface
    //! [`io-streams`]: https://crates.io/crates/io-streams
    //! [`getrandom`]: https://crates.io/crates/getrandom
    //! [`bitflags`]: https://crates.io/crates/bitflags
    //! [`AsFd`]: https://doc.rust-lang.org/stable/std/os/unix/io/trait.AsFd.html
    //! [`OwnedFd`]: https://docs.rs/io-lifetimes/latest/io_lifetimes/struct.OwnedFd.html
    //! [io-lifetimes crate]: https://crates.io/crates/io-lifetimes
    //! [I/O-safe]: https://github.com/rust-lang/rfcs/blob/master/text/3128-io-safety.md
    //! [`Result`]: https://docs.rs/rustix/latest/rustix/io/type.Result.html
    //! [`Arg`]: https://docs.rs/rustix/latest/rustix/path/trait.Arg.html

    #![deny(missing_docs)]
    #![allow(stable_features)]
    #![cfg_attr(linux_raw, deny(unsafe_code))]
    #![cfg_attr(rustc_attrs, feature(rustc_attrs))]
    #![cfg_attr(doc_cfg, feature(doc_cfg))]
    #![cfg_attr(all(target_os = "wasi", feature = "std"), feature(wasi_ext))]
    #![cfg_attr(
        all(linux_raw, naked_functions, target_arch = "x86"),
        feature(naked_functions)
    )]
    #![cfg_attr(io_lifetimes_use_std, feature(io_safety))]
    #![cfg_attr(core_ffi_c, feature(core_ffi_c))]
    #![cfg_attr(core_c_str, feature(core_c_str))]
    #![cfg_attr(alloc_c_string, feature(alloc_ffi))]
    #![cfg_attr(alloc_c_string, feature(alloc_c_string))]
    #![cfg_attr(not(feature = "std"), no_std)]
    #![cfg_attr(feature = "rustc-dep-of-std", feature(core_intrinsics))]
    #![cfg_attr(feature = "rustc-dep-of-std", feature(ip))]
    #![cfg_attr(
        all(not(feature = "rustc-dep-of-std"), core_intrinsics),
        feature(core_intrinsics)
    )]
    #![cfg_attr(asm_experimental_arch, feature(asm_experimental_arch))]
    #![cfg_attr(not(feature = "all-apis"), allow(dead_code))]
    // Clamp depends on Rust 1.50 which is newer than our MSRV.
    #![allow(clippy::manual_clamp)]
    // It is common in linux and libc APIs for types to vary between platforms.
    #![allow(clippy::unnecessary_cast)]
    // It is common in linux and libc APIs for types to vary between platforms.
    #![allow(clippy::useless_conversion)]

    #[cfg(not(feature = "rustc-dep-of-std"))]
    extern crate alloc;

    // Internal utilities.
    #[cfg(not(windows))]
    #[macro_use]
    pub(crate) mod cstr;
    #[macro_use]
    pub(crate) mod const_assert;
    pub(crate) mod utils;

    // Pick the backend implementation to use.
    #[cfg_attr(libc, path = "backend/libc/mod.rs")]
    #[cfg_attr(linux_raw, path = "backend/linux_raw/mod.rs")]
    #[cfg_attr(wasi, path = "backend/wasi/mod.rs")]
    mod backend;

    /// Export the `*Fd` types and traits that are used in rustix's public API.
    ///
    /// Users can use this to avoid needing to import anything else to use the same
    /// versions of these types and traits.
    pub mod fd {
        use super::backend;
        #[cfg(windows)]
        pub use backend::fd::AsSocket;
        pub use backend::fd::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
    }

    // The public API modules.
    #[cfg(not(windows))]
    pub mod ffi;
    #[cfg(not(windows))]
    #[cfg(feature = "fs")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "fs")))]
    pub mod fs;
    pub mod io;
    #[cfg(any(target_os = "android", target_os = "linux"))]
    #[cfg(feature = "io_uring")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "io_uring")))]
    pub mod io_uring;
    #[cfg(not(any(windows, target_os = "wasi")))]
    #[cfg(feature = "mm")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "mm")))]
    pub mod mm;
    #[cfg(not(any(target_os = "redox", target_os = "wasi")))]
    #[cfg(feature = "net")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "net")))]
    pub mod net;
    #[cfg(not(windows))]
    #[cfg(feature = "param")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "param")))]
    pub mod param;
    #[cfg(not(windows))]
    #[cfg(any(feature = "fs", feature = "net"))]
    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "fs", feature = "net"))))]
    pub mod path;
    #[cfg(not(windows))]
    #[cfg(feature = "process")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "process")))]
    pub mod process;
    #[cfg(not(windows))]
    #[cfg(feature = "rand")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "rand")))]
    pub mod rand;
    #[cfg(not(windows))]
    #[cfg(feature = "termios")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "termios")))]
    pub mod termios;
    #[cfg(not(windows))]
    #[cfg(feature = "thread")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "thread")))]
    pub mod thread;
    #[cfg(not(windows))]
    #[cfg(feature = "time")]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "time")))]
    pub mod time;

    // "runtime" is also a public API module, but it's only for libc-like users.
    #[cfg(not(windows))]
    #[cfg(feature = "runtime")]
    #[doc(hidden)]
    #[cfg_attr(doc_cfg, doc(cfg(feature = "runtime")))]
    pub mod runtime;

    // We have some internal interdependencies in the API features, so for now,
    // for API features that aren't enabled, declare them as `pub(crate)` so
    // that they're not public, but still available for internal use.

    #[cfg(not(windows))]
    #[cfg(all(
        not(feature = "param"),
        any(feature = "runtime", feature = "time", target_arch = "x86"),
    ))]
    pub(crate) mod param;
    #[cfg(not(windows))]
    #[cfg(not(any(feature = "fs", feature = "net")))]
    pub(crate) mod path;
    #[cfg(not(windows))]
    #[cfg(not(feature = "process"))]
    pub(crate) mod process;