Auto merge of #23002 - pnkfelix:fsk-box-place-runway, r=nikomatsakis

Runway for RFC 809 (overloaded box/placement-in) by adding type annotations or explicit calls to `Box::new` where I found it necessary on PR #22086.

I have broken this up into more than one PR because the entire commit chain (see PR #22086) is long, widespread and unwieldy to rebase frequently.

To my knowledge this is not a breaking change.  Also, there is in principle nothing stopping someone from reverting some/all of these annotations, since without the rest of the commit chain in #22086, the associated code would continue to compile.

All I can do is ask: Try to discourage others from removing seemingly "unnecessary" uses of the `Box` type or the `Box::new()` function, until the rest of RFC 809 lands.

3 files changed, 6 insertions, 6 deletions

diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs
index ee8bef50d89..1a1e9e69e71 100644
--- a/src/libstd/sync/mpsc/mod.rs
+++ b/src/libstd/sync/mpsc/mod.rs
@@ -1044,13 +1044,13 @@ mod test {
 
     #[test]
     fn drop_full() {
-        let (tx, _rx) = channel();
+        let (tx, _rx) = channel::<Box<int>>();
         tx.send(box 1).unwrap();
     }
 
     #[test]
     fn drop_full_shared() {
-        let (tx, _rx) = channel();
+        let (tx, _rx) = channel::<Box<int>>();
         drop(tx.clone());
         drop(tx.clone());
         tx.send(box 1).unwrap();
@@ -1389,7 +1389,7 @@ mod test {
     #[test]
     fn oneshot_multi_thread_send_recv_stress() {
         for _ in 0..stress_factor() {
-            let (tx, rx) = channel();
+            let (tx, rx) = channel::<Box<int>>();
             let _t = thread::spawn(move|| {
                 tx.send(box 10).unwrap();
             });
@@ -1566,7 +1566,7 @@ mod sync_tests {
 
     #[test]
     fn drop_full() {
-        let (tx, _rx) = sync_channel(1);
+        let (tx, _rx) = sync_channel::<Box<int>>(1);
         tx.send(box 1).unwrap();
     }
 
diff --git a/src/libstd/sync/mpsc/mpsc_queue.rs b/src/libstd/sync/mpsc/mpsc_queue.rs
index 59fa2e6bc9a..14ed253d8e2 100644
--- a/src/libstd/sync/mpsc/mpsc_queue.rs
+++ b/src/libstd/sync/mpsc/mpsc_queue.rs
@@ -164,7 +164,7 @@ mod tests {
 
     #[test]
     fn test_full() {
-        let q = Queue::new();
+        let q: Queue<Box<_>> = Queue::new();
         q.push(box 1);
         q.push(box 2);
     }
diff --git a/src/libstd/sync/mpsc/spsc_queue.rs b/src/libstd/sync/mpsc/spsc_queue.rs
index ce40fa2672a..3fb13739aa7 100644
--- a/src/libstd/sync/mpsc/spsc_queue.rs
+++ b/src/libstd/sync/mpsc/spsc_queue.rs
@@ -289,7 +289,7 @@ mod test {
     #[test]
     fn drop_full() {
         unsafe {
-            let q = Queue::new(0);
+            let q: Queue<Box<_>> = Queue::new(0);
             q.push(box 1);
             q.push(box 2);
         }