Document when types have OS-dependent sizes
As per issue #43601, types that can change size depending on the
target operating system should say so in their documentation.
I used this template when adding doc comments:
```
The size of a(n) <name> struct may vary depending on the target
operating system, and may change between Rust releases.
```
For enums, I used "instance" instead of "struct".
I added documentation to these types:
```
- std::time::Instant (contains sys::time::Instant)
- std::time::SystemTime (contains sys::time::SystemTime)
- std::io::StdinRaw (contains sys::stdio::Stdin)
- std::io::StdoutRaw (contains sys::stdio::Stdout)
- std::io::Stderr (contains sys::stdio::Stderr)
- std::net::addr::SocketAddrV4 (contains sys::net::netc::sockaddr_in)
- std::net::addr::SocketAddrV6 (contains sys::net::netc::sockaddr_in6)
- std::net::addr::SocketAddr (contains std::net::addr::SocketAddrV4 and SocketAddrV6)
- std::net::ip::Ipv4Addr (contains sys::net::netc::in_addr)
- std::net::ip::Ipv6Addr (contains sys::net::netc::in6_addr)
- std::net::ip::IpAddr (contains std::net::ip::Ipv4Addr and Ipv6Addr)
```
I also found that these types varied in size; however, I don't think they need documentation, as it's already fairly obvious that they change based on different OS's:
```
- std::fs::DirBuilder (contains sys::fs::DirBuilder)
- std::fs::FileType (contains sys::fs::FileType)
- std::fs::Permissions (contains sys::fs::FilePermissions)
- std::fs::OpenOptions (contains sys::fs::OpenOptions)
- std::fs::DirEntry (contains sys::fs::DirEntry)
- std::fs::ReadDir (contains sys::fs::ReadDir)
- std::fs::Metadata (contains sys::fs::FileAttr)
- std::fs::File (contains sys::fs::File)
- std::process::Child (contains sys::process::Process)
- std::process::ChildStdin (contains sys::process::AnonPipe)
- std::process::ChildStdout (contains sys::process::AnonPipe)
- std::process::ChildStderr (contains sys::process::AnonPipe)
- std::process::Command (contains sys::process::Command)
- std::process::Stdio (contains sys::process::Stdio)
- std::process::ExitStatus (contains sys::process::ExitStatus)
- std::process::Output (contains std::process::ExitStatus)
- std::sys_common::condvar::Condvar (contains sys::condvar::Condvar)
- std::sys_common::mutex::Mutex (contains sys::mutex::Mutex)
- std::sys_common::net::LookupHost (contains sys::net::netc::addrinfo)
- std::sys_common::net::TcpStream (contains sys::net::Socket)
- std::sys_common::net::TcpListener (contains sys::net::Socket)
- std::sys_common::net::UdpSocket (contains sys::net::Socket)
- std::sys_common::remutex::ReentrantMutex (contains sys::mutex::ReentrantMutex)
- std::sys_common::rwlock::RWLock (contains sys::rwlock::RWLock)
- std::sys_common::thread_local::Key (contains sys::thread_local::Key)
```
Maybe we should just put a comment about the size of structs in the module-level docs for `fs`, `process`, and `sys_common`?
If anyone can think of other types that can change size, comment below. I'm also open to changing the wording.
closes#43601.
As per issue #43601, types that can change size depending on the
target operating system should say so in their documentation.
I used this template when adding doc comments:
The size of a(n) <name> struct may vary depending on the target
operating system, and may change between Rust releases.
For enums, I used "instance" instead of "struct".
There are some tests that need to be disabled on CloudABI specifically,
due to the fact that the shims cannot be built in combination with
unix::ext or windows::ext. Also improve the scoping of some imports to
suppress compiler warnings.
Linux appears to set POLLOUT when a conection's refused, which is pretty
weird. Invert the check to look for an error explicitly. Also add an
explict test for this case.
Closes#45265.
Fix TcpStream::local_addr docs example code
The local address's port is not 8080 in this example, that's the remote peer address port. On my machine, the local address is different every time, so I've changed `assert_eq` to only test the IP address
The local address's port is not 8080 in this example, that's the remote peer address port. On my machine, the local address is different every time, so I've changed `assert_eq` to only test the IP address
Ensure tcp test case passes when disconnected from network
net::tcp::tests::connect_timeout_unroutable fails when the network
is unreachable, like on a laptop disconnected from wifi. Check for
this error and allow the test to pass.
Closes#44645
net::tcp::tests::connect_timeout_unroutable fails when the network
is unreachable, like on a laptop disconnected from wifi. Check for
this error and allow the test to pass.
Closes#44645
Ipv4Addr and Ipv6Addr convenience constructors.
Introduce convenience constructors for common types.
This introduces the following constructors:
* Ipv6Addr::localhost()
* Ipv6Addr::unspecified()
* Ipv4Addr::localhost()
* Ipv4Addr::unspecified()
The recently added `From` implementations were nice for avoiding the fallibility of conversions from strings like `"127.0.0.1".parse().unwrap()`, and `"::1".parse().unwrap()`, but while the Ipv4 version is roughly comparable in verbosity, the Ipv6 version lacks zero-segment elision, which makes it significantly more awkward: `[0, 0, 0, 0, 0, 0, 0, 0].into()`. While there isn't a clear way to introduce zero elision to type that can infallibly be converted into Ipv6 addresses, this PR resolves the problem for the two most commonly used addresses, which, incidentally, are the ones that suffer the most from the lack of zero-segment elision.
This change is dead simple, and introduces no backwards incompatibility.
See also, [this topic on the inernals board](https://internals.rust-lang.org/t/pre-rfc-convenience-ip-address-constructors/5878)
