Improve std::net docs
Fixes#29363
Summary:
* Added a _lot_ of missing links, both to other types/methods and to IETF RFCs, and changed occurences of just "RFC" to "IETF RFC"
* Expanded a bunch of top-level docs, specifically the module docs & the docs for `TcpListener`, `TcpStream`, `UdpSocket`, `IpAddr`, `Ipv4Addr`, `Ipv6Addr`, `SocketAddr`, `SocketAddrV4`, `SocketAddrV6`,
* Expanded method docs for `SocketAddrV6`, `AddrParseError`,
* Various edits for clarity, consistency, and accuracy
See the commit descriptions for more detail.
Things not done quite as laid out in the task list in #29363:
* `AddrParseError` still doesn't have examples, but I wasn't quite sure how to do them; other `FromStr` error types don't have any, either
* I didn't link to an IETF RFC in `IpAddr`, but in `Ipv4Addr` and `Ipv6Addr` and linked tho those from `IpAddr`; this seems more appropriate to me
* Similarly, I didn't really exand `SocketAddr`'s docs, but elaborated on `SocketAddrV4` and `SocketAddrV6`'s and linked to them from `SocketAddr`
Theres definitely still room for improvement, but this should be a good first effort 😄
Document Cursor::new position is 0
... even if contained `Vec` is not empty. E. g. for
```
let v = vec![10u8, 20];
let mut c = io::Cursor::new(v);
c.write_all(b"aaaa").unwrap();
println!("{:?}", c.into_inner());
```
result is
```
[97, 97, 97, 97]
```
and not
```
[10, 20, 97, 97, 97, 97]
```
std: Don't cache stdio handles on Windows
This alters the stdio code on Windows to always call `GetStdHandle` whenever the
stdio read/write functions are called as this allows us to track changes to the
value over time (such as if a process calls `SetStdHandle` while it's running).
Closes#40490
* Fixed spelling ToSocketAddr -> ToSocketAddrs in module docs
(which also fixes a link)
* Added missing "when" before "interacting" in module docs
* Changed SocketAddr's top-level docs to explicitly state what socket
addresses consist of, making them more consistent with SocketAddrV4's
and SocketAddrV6's docs
* Changed "in C" -> "in C's `netinet/in.h`"
* Changed wording in is_ipv4/is_ipv6 methods to ", `false` otherwise"
* Add missing closing ` ``` ` in Ipv6Addr's examples
* Removed "Errors" section in ToSocketAddrs' to_socket_addrs method as it
was rather redundant
This is useful to build os abstraction like the nix crate does.
It allows to define functions, which accepts generic arguments
of data structures convertible to RawFd, including RawFd itself.
For example:
fn write<FD: AsRawFd>(fd: FD, buf: &[u8]) -> Result<usize>
instead of:
fn write(fd: RawFd, buf: &[u8]) -> Result<usize>
write(foo.as_raw_fd(), buf);
Part of #29363
Changed summary sentences of SocketAddr and IpAddr for consistency
Linked to SocketAddrV4 and SocketAddrV6 from SocketAddr, moving explaination
there
Expanded top-level docs for SocketAddrV4 and SocketAddrV6, linking to some
relevant IETF RFCs, and linking back to SocketAddr
Changed some of the method summaries to third person as per RFC 1574; added
links to IETF RFCs where appropriate
Part of #29363
Expanded top-level documentation & linked to relevant IETF RFCs.
Added a bunch of links (to true/false/Ipv4Addr/etc.) throughout the docs.
Part of #29363
In the section about the default implementations of ToSocketAddrs,
I moved the bulletpoint of SocketAddrV4 & SocketAddrV6 to the one
stating that SocketAddr is constructed trivially, as this is what's
actually the case
Before the docs only had a line about where it was found and that it was
a handle to stderr. This commit changes it so that the summary second line is
removed and that it's a bit clearer about what can be done with it. Part of
\#29370
Rewrite `io::BufRead` doc examples to better demonstrate behaviors.
Prior to this commit, most of the `BufRead` examples used `StdinLock` to
demonstrate how certain `BufRead` methods worked. Using `StdinLock` is
not ideal since:
* Relying on run-time data means we can't show concrete examples of how
these methods work up-front. The user is required to run them in order
to see how they behave.
* If the user tries to run an example in the playpen, it won't work
because the playpen doesn't support user input to stdin.
In #29370 it's noted that for "the Note shouldn't be one, and should come before
the examples." This commit changes the positioning of the section and removes
wording that said take note in order for it to flow better with the surrounding
text and it's new position.
Fix formatting in the docs for std::process::Command::envs()
An empty line between the *Basic usage:* text and the example is required to properly format the code. Without the empty line, the example is not formatted as code.
[Here](https://doc.rust-lang.org/std/process/struct.Command.html#method.envs) you can see the current (improper) formatting.
The person who originally wrote the example forgot to include this attribute.
This caused Travis CI to fail on commit 9b0a4a4e97 (#40794), which just fixed
formatting in the description of std::process::Command::envs().
An empty line between the "Basic usage:" text and the example is required to
properly format the code. Without the empty line, the example is not formatted
as code.
Prior to this commit, most of the `BufRead` examples used `StdinLock` to
demonstrate how certain `BufRead` methods worked. Using `StdinLock` is
not ideal since:
* Relying on run-time data means we can't show concrete examples of how
these methods work up-front. The user is required to run them in order
to see how they behave.
* If the user tries to run an example in the playpen, it won't work
because the playpen doesn't support user input to stdin.
... even if contained `Vec` is not empty. E. g. for
```
let v = vec![10u8, 20];
let mut c = io::Cursor::new(v);
c.write_all(b"aaaa").unwrap();
println!("{:?}", c.into_inner());
```
result is
```
[97, 97, 97, 97]
```
and not
```
[10, 20, 97, 97, 97, 97]
```
