Struct std::os::wasi::io::BorrowedFd

#[repr(transparent)]
pub struct BorrowedFd<'fd> { /* private fields */ }

Available on WASI only.

A borrowed file descriptor.

This has a lifetime parameter to tie it to the lifetime of something that owns the file descriptor.

This uses repr(transparent) and has the representation of a host file descriptor, so it can be used in FFI in places where a file descriptor is 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.

Implementations

impl BorrowedFd<'_>

pub const unsafe fn borrow_raw(fd: RawFd) -> Self

Return a BorrowedFd holding the given raw file descriptor.

Safety

The resource pointed to by fd must remain open for the duration of the returned BorrowedFd, and it must not have the value -1.

impl BorrowedFd<'_>

pub fn try_clone_to_owned(&self) -> Result<OwnedFd>

Creates a new OwnedFd instance that shares the same underlying file description as the existing BorrowedFd instance.

Trait Implementations

impl AsFd for BorrowedFd<'_>

fn as_fd(&self) -> BorrowedFd<'_>

Available on Unix only.

Borrows the file descriptor.

impl AsRawFd for BorrowedFd<'_>

fn as_raw_fd(&self) -> RawFd

Available on Unix only.

Extracts the raw file descriptor.

impl<'fd> Clone for BorrowedFd<'fd>

fn clone(&self) -> BorrowedFd<'fd>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BorrowedFd<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'fd> Copy for BorrowedFd<'fd>