Revert "avoid bounds check in Waker::try_select method"

This reverts commit 10009bd.

crossbeam-channel/src/waker.rs

@@ -77,26 +77,34 @@ impl Waker {
     /// Attempts to find another thread's entry, select the operation, and wake it up.
     #[inline]
     pub(crate) fn try_select(&mut self) -> Option<Entry> {
-        self.selectors
-            .iter()
-            .position(|selector| {
+        let mut entry = None;
+
+        if !self.selectors.is_empty() {
+            let thread_id = current_thread_id();
+
+            for i in 0..self.selectors.len() {
                 // Does the entry belong to a different thread?
-                selector.cx.thread_id() != current_thread_id()
-                    && selector // Try selecting this operation.
-                        .cx
-                        .try_select(Selected::Operation(selector.oper))
-                        .is_ok()
-                    && {
+                if self.selectors[i].cx.thread_id() != thread_id {
+                    // Try selecting this operation.
+                    let sel = Selected::Operation(self.selectors[i].oper);
+                    let res = self.selectors[i].cx.try_select(sel);
+
+                    if res.is_ok() {
                         // Provide the packet.
-                        selector.cx.store_packet(selector.packet);
+                        self.selectors[i].cx.store_packet(self.selectors[i].packet);
                         // Wake the thread up.
-                        selector.cx.unpark();
-                        true
+                        self.selectors[i].cx.unpark();
+
+                        // Remove the entry from the queue to keep it clean and improve
+                        // performance.
+                        entry = Some(self.selectors.remove(i));
+                        break;
                     }
-            })
-            // Remove the entry from the queue to keep it clean and improve
-            // performance.
-            .map(|pos| self.selectors.remove(pos))
+                }
+            }
+        }
+
+        entry
     }
 
     /// Returns `true` if there is an entry which can be selected by the current thread.