async-std/src/os/windows/io.rs

//! Windows-specific I/O extensions.

use cfg_if::cfg_if;

cfg_if! {
    if #[cfg(feature = "docs.rs")] {
        /// Raw HANDLEs.
        pub type RawHandle = *mut std::os::raw::c_void;

        /// Raw SOCKETs.
        pub type RawSocket = u64;

        /// Extracts raw handles.
        pub trait AsRawHandle {
            /// Extracts the raw handle, without taking any ownership.
            fn as_raw_handle(&self) -> RawHandle;
        }

        /// Construct I/O objects from raw handles.
        pub trait FromRawHandle {
            /// Constructs a new I/O object from the specified raw handle.
            ///
            /// This function will **consume ownership** of the handle given,
            /// passing responsibility for closing the handle to the returned
            /// object.
            ///
            /// This function is also unsafe as the primitives currently returned
            /// have the contract that they are the sole owner of the file
            /// descriptor they are wrapping. Usage of this function could
            /// accidentally allow violating this contract which can cause memory
            /// unsafety in code that relies on it being true.
            unsafe fn from_raw_handle(handle: RawHandle) -> Self;
        }

        /// A trait to express the ability to consume an object and acquire ownership of
        /// its raw `HANDLE`.
        pub trait IntoRawHandle {
            /// Consumes this object, returning the raw underlying handle.
            ///
            /// This function **transfers ownership** of the underlying handle to the
            /// caller. Callers are then the unique owners of the handle and must close
            /// it once it's no longer needed.
            fn into_raw_handle(self) -> RawHandle;
        }
    } else {
        #[doc(inline)]
        pub use std::os::windows::io::{
            AsRawHandle, FromRawHandle, IntoRawHandle, RawHandle, RawSocket,
        };
    }
}