docs: Small clarification on the usage of read_to_string and read_to_end trait methods

[kiseitai3]

Small clarification on the usage of read_to_string and read_to_end trait methods. The goal is to make it clear that these trait methods will become locked up if attempting to read to the end of stdin (which is a bit non-sensical unless the other end closes the pipe).

Fixes: rust-lang/rust#141714

[rustbot]

r? @joboet

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[rustbot]

:warning: Warning :warning:

• Some commits in this PR modify submodules.

[kiseitai3]

This is follow up work on #141935. If possible, reassign to @tgross35. A mistake was made in the previous PR. I attempted a rebase and one thing led to another and the branch became a mess, so I killed the branch. That autoclosed the old PR, so I opened a new one with changes more in line with what Trevor asked.

Sorry, but I hope this PR is more like what is expected in this project.

[rust-log-analyzer]

The job mingw-check-2 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

 Documenting std v0.0.0 (/checkout/library/std)
error: unresolved link to `read`
   --> library/std/src/io/mod.rs:929:58
    |
929 |     /// Using `.lines()` with a [`BufReader`] or using [`read`] can provide a better solution
    |                                                          ^^^^ no item named `read` in scope
    |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
    = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`

error: unresolved link to `read`
   --> library/std/src/io/mod.rs:983:58
    |
983 |     /// Using `.lines()` with a [`BufReader`] or using [`read`] can provide a better solution
    |                                                          ^^^^ no item named `read` in scope
    |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

error: unresolved link to `read`
    --> library/std/src/io/mod.rs:1297:54
     |
1297 | /// Using `.lines()` with a [`BufReader`] or using [`read`] can provide a better solution
     |                                                      ^^^^ no item named `read` in scope
     |
     = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

error: could not document `std`
warning: build failed, waiting for other jobs to finish...
[RUSTC-TIMING] std test:false 7.739
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:01:00
  local time: Fri Jun  6 01:56:08 UTC 2025
  network time: Fri, 06 Jun 2025 01:56:08 GMT
##[error]Process completed with exit code 1.
Post job cleanup.

[tgross35]

If possible, reassign to @tgross35

I'll let you do this yourself for the experience :) you can request reviews by posting a comment, see rustbot's guidelines:

Use r? to explicitly pick a reviewer

[tgross35]

Also it looks like you accidentally picked up a submodule change here. There's about 1000 different ways to fix this but if you need a suggestion, I would do something like this:

# Reset to the point where your branch forked from `master`. The reset will get rid
# of your commit and mark all of the files as staged
git reset "$(git merge-base HEAD master)"

# Add the thing you care about
git add library/std

# Get ride of the unintentional changes
git restore src/doc

# Re-commit the files (now only what you care about) using 🪄 magic 🪄 to
# reuse the commit message you have now
git commit -C HEAD@{1}

# Update this PR
git push --force-with-lease

Also, you can always check exactly what your PR will look like before pushing with git diff "$(git merge-base HEAD master)", to avoid things like whatever bad luck you ran into with https://github.com/rust-lang/rust/pull/141935#issuecomment-2947716827.

(happy to help with git stuff if you have further questions)

[kiseitai3]

I'm not using git from the terminal. I am using it through RustRover and I assumed it had only picked up my modified file since I had not changed anything. However, I do see failure messages for what appear to be automatic attempts at running repository actions. I did not look closely since I have very little personal time for coding and I kinda wanted to move on with a milestone in my own personal project. I will need to correct that in my IDE settings. That's annoying.

I have used git in the terminal before so maybe that would have given me a clue. Maybe one of these days I will convert to Vim and embrace the terminal more (which is ironic considering I use the terminal 24/7 at work).

r? @tgross35

P.S. > Completely missed the docs changes getting picked up.

[rustbot]

:warning: Warning :warning:

• Some commits in this PR modify submodules.

• The following commits have merge commits (commits with multiple parents) in your changes. We have a no merge policy so these commits will need to be removed for this pull request to be merged.

  • 6bc0f7f62ff466115e7dca17225f6eaa86d9e59a

  You can start a rebase with the following commands:

  $ # rebase
  $ git pull --rebase https://github.com/rust-lang/rust.git master
  $ git push --force-with-lease
  

[tgross35]

This looks great to me, thank you for the changes! You don't need to mention me in the commit though, just describe what you did since it is your work :)

For the submodule thing - git usually marks submodules as unstaged changes if you don't update them when changing branches / rebasing / etc, so anything that does git add . or git commit -a to commit all files will pick them up even when you never touched the file. Just submodules being a bit annoying, unfortunately.

[kiseitai3]

This looks great to me, thank you for the changes! You don't need to mention me in the commit though, just describe what you did since it is your work :)

For the submodule thing - git usually marks submodules as unstaged changes if you don't update them when changing branches / rebasing / etc, so anything that does git add . or git commit -a to commit all files will pick them up even when you never touched the file. Just submodules being a bit annoying, unfortunately.

I have learned quite a bit from you on git. Since I don't solely use git on the terminal or via IDEs, I don't have as deep experience with terminal git. I am going to save the instructions above to a cheatsheet to recover from bad commits in the future.

Thank you!

P.S. > I wish I was compiler designer smart. Impressive work you all have done. With that said, my hope is to make Rust core to my development so maybe I will get more chances to contribute in the future.

[tgross35]

Recovering from bad commits becomes mandatory learning at some point 😆

P.S. > I wish I was compiler designer smart.

You are, you just made your first contribution to a rather impressive project :) Welcome and thank you for the persistence here!

I force pushed your branch to make the commit message match this PR's title, so with that:

@bors r+ rollup

[bors]

:pushpin: Commit 7d7fedbab4bd4ff030ac98640f2f18f94041d433 has been approved by tgross35

It is now in the queue for this repository.