bjoernager/rust
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add an example to explain std::io::Read::read returning 0 in some cases

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the example focuses on Linux, but that should be enough to explain how
the behaviour can change
This commit is contained in:
Geoffroy Couprie 2021-05-14 15:12:33 +02:00
parent 69b352ef77
commit 95ccdb11da
1 changed files with 7 additions and 1 deletions
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8
library/std/src/io/mod.rs
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@ -526,7 +526,12 @@ pub trait Read {
/// ///
/// 1. This reader has reached its "end of file" and will likely no longer /// 1. This reader has reached its "end of file" and will likely no longer
/// be able to produce bytes. Note that this does not mean that the /// be able to produce bytes. Note that this does not mean that the
/// reader will *always* no longer be able to produce bytes. /// reader will *always* no longer be able to produce bytes. As an example,
/// on Linux, this method will call the `recv` syscall for a [`TcpStream`],
/// where returning zero indicates the connection was shut down correctly. While
/// for [`File`], it is possible to reach the end of file and get zero as result,
/// but if more data is appended to the file, future calls to `read` will return
/// more data.
/// 2. The buffer specified was 0 bytes in length. /// 2. The buffer specified was 0 bytes in length.
/// ///
/// It is not an error if the returned value `n` is smaller than the buffer size, /// It is not an error if the returned value `n` is smaller than the buffer size,
@ -568,6 +573,7 @@ pub trait Read {
/// ///
/// [`Ok(n)`]: Ok /// [`Ok(n)`]: Ok
/// [`File`]: crate::fs::File /// [`File`]: crate::fs::File
/// [`TcpStream`]: crate::net::TcpStream
/// ///
/// ```no_run /// ```no_run
/// use std::io; /// use std::io;