Multiple I/O of the same type is not supported

fix #1682
2019-08-29 10:55:47 -07:00
parent e681f9d212
commit c5d8c7b64c
2 changed files with 8 additions and 0 deletions
@@ -70,6 +70,13 @@ struct stream_base
        pending_guard(bool& b)
            : b_(b)
        {
+            // If this assert goes off, it means you are attempting
+            // to issue two of the same asynchronous I/O operation
+            // at the same time, without waiting for the first one
+            // to complete. For example, attempting two simultaneous
+            // calls to async_read_some. Only one pending call of
+            // each I/O type (read and write) is permitted.
+            //
            BOOST_ASSERT(! b_);
            b_ = true;
        }