libs (net)
Introduce and implement IntoRaw{Fd, Socket, Handle} traits to complement the
existing AsRaw{Fd, Socket, Handle} traits already in the standard library.
The FromRaw{Fd, Socket, Handle} traits each take ownership of the provided
handle, however, the AsRaw{Fd, Socket, Handle} traits do not give up
ownership. Thus, converting from one handle wrapper to another (for example
converting an open fs::File to a process::Stdio) requires the caller to
either manually dup the handle, or mem::forget the wrapper, which
is unergonomic and can be prone to mistakes.
Traits such as IntoRaw{Fd, Socket, Handle} will allow for easily transferring
ownership of OS handles, and it will allow wrappers to perform any
cleanup/setup as they find necessary.
The IntoRaw{Fd, Socket, Handle} traits will behave exactly like their
AsRaw{Fd, Socket, Handle} counterparts, except they will consume the wrapper
before transferring ownership of the handle.
Note that these traits should not have a blanket implementation over T: AsRaw{Fd, Socket, Handle}: these traits should be opt-in so that implementors
can decide if leaking through mem::forget is acceptable or another course of
action is required.
// Unix
pub trait IntoRawFd {
fn into_raw_fd(self) -> RawFd;
}
// Windows
pub trait IntoRawSocket {
fn into_raw_socket(self) -> RawSocket;
}
// Windows
pub trait IntoRawHandle {
fn into_raw_handle(self) -> RawHandle;
}
This adds three new traits and methods which would have to be maintained.
Instead of defining three new traits we could instead use the
std::convert::Into<T> trait over the different OS handles. However, this
approach will not offer a duality between methods such as
as_raw_fd()/into_raw_fd(), but will instead be as_raw_fd()/into().
Another possibility is defining both the newly proposed traits as well as the
Into<T> trait over the OS handles letting the caller choose what they prefer.
None at the moment.