Update intro.md to fix thread spawning example Closes #22419

[diamondman]

Fixed example threaded code in intro doc never printing results. Threads were created with Thread::spawn instead of Thread::scoped. Also added correct thread handling like in the first example of the document.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @steveklabnik (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. The way Github handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see CONTRIBUTING.md for more information.

[steveklabnik]

@bors: r+ c2600cf rollup

[steveklabnik]

Thank you!

[diamondman]

What does the rollup command mean?

[steveklabnik]

Here's the patch queue: http://buildbot.rust-lang.org/homu/queue/rust

basically, it means that this is a low-impact change that's not likely to fail the tests. we mark any PRs that feel right as rollups, and then, when any rollup commit gets built or we kick one off manually, they all get done at once.

[Manishearth]

(needs rebase)

[diamondman]

I am not sure to tell what the conflict was because of how the branches are rolled together through a rollup.

[Manishearth]

It's 8c34b26, Niko removed us/is suffixes

diff --git a/src/doc/intro.md b/src/doc/intro.md
index 90a018c..d9bfe71 100644
--- a/src/doc/intro.md
+++ b/src/doc/intro.md
@@ -480,7 +480,7 @@ use std::sync::{Arc,Mutex};
 fn main() {
     let numbers = Arc::new(Mutex::new(vec![1, 2, 3]));

-    for i in 0us..3 {
+    for i in 0..3 {
         let number = numbers.clone();
         Thread::spawn(move || {
             let mut array = number.lock().unwrap();
@@ -541,7 +541,7 @@ use std::thread::Thread;
 fn main() {
     let vec = vec![1, 2, 3];

-    for i in 0us..3 {
+    for i in 0..3 {
         Thread::spawn(move || {
             println!("{}", vec[i]);
         });

Generally I don't hunt down merge conflicts, I just git fetch origin; git rebase -i origin/master, and use git mergetool (I prefer meld personally) to fix them -- this way you get a focused view of conflicting files and tools to fix the conflicts.

[diamondman]

Would I not have to pull the newest master and then merge each of the branches that are in the roll up manually and then see which one has a conflict? And will I be able to fix this conflict since it is in someone else's fork?

[steveklabnik]

@diamondman the issue is that it doesn't build against master, not other rollup PRs. in general, the rollup is a thing you shouldn't have to worry about.

[Manishearth]

No. All the changes from the rollup are on master.

The conflict is between your branch and master.

[Manishearth]

(To be fair, when I notice that there is a conflict with a not-yet-merged rollup I'll either fix it myself or notify the author, but then I give sufficient details)

[Manishearth]

Also, as mentioned before, it's far easier using rebase/mergetool and letting Git do most of the work for you :)

[diamondman]

Ah, I understand. Thanks. I will merge on push up

[Manishearth]

@bors: r=steveklabnik 6154c88 rollup