diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs index a1f83029d2727..5833c59725682 100644 --- a/library/std/src/os/fd/owned.rs +++ b/library/std/src/os/fd/owned.rs @@ -24,9 +24,14 @@ use crate::sys_common::{AsInner, FromInner, IntoInner}; /// passed as an argument, it is not captured or consumed, and it never has the /// value `-1`. /// -/// This type's `.to_owned()` implementation returns another `BorrowedFd` -/// rather than an `OwnedFd`. It just makes a trivial copy of the raw file -/// descriptor, which is then borrowed under the same lifetime. +/// This type does not have a [`ToOwned`][crate::borrow::ToOwned] +/// implementation. Calling `.to_owned()` on a variable of this type will call +/// it on `&BorrowedFd` and use `Clone::clone()` like `ToOwned` does for all +/// types implementing `Clone`. The result will be descriptor borrowed under +/// the same lifetime. +/// +/// To obtain an [`OwnedFd`], you can use [`BorrowedFd::try_clone_to_owned`] +/// instead, but this is not supported on all platforms. #[derive(Copy, Clone)] #[repr(transparent)] #[rustc_layout_scalar_valid_range_start(0)] @@ -50,6 +55,8 @@ pub struct BorrowedFd<'fd> { /// descriptor, so it can be used in FFI in places where a file descriptor is /// passed as a consumed argument or returned as an owned value, and it never /// has the value `-1`. +/// +/// You can use [`AsFd::as_fd`] to obtain a [`BorrowedFd`]. #[repr(transparent)] #[rustc_layout_scalar_valid_range_start(0)] // libstd/os/raw/mod.rs assures me that every libstd-supported platform has a