Improve the documented advice on how to best use heapq.heapreplace().
diff --git a/Lib/heapq.py b/Lib/heapq.py
index 09f996a..9fb4e70 100644
--- a/Lib/heapq.py
+++ b/Lib/heapq.py
@@ -154,7 +154,9 @@
This is more efficient than heappop() followed by heappush(), and can be
more appropriate when using a fixed-size heap. Note that the value
returned may be larger than item! That constrains reasonable uses of
- this routine.
+ this routine unless written as part of a larger expression:
+
+ result = item <= heap[0] and item or heapreplace(heap, item)
"""
returnitem = heap[0] # raises appropriate IndexError if heap is empty
heap[0] = item