Fix error in doxygen comment.

asio/include/asio/basic_signal_set.hpp

diff --git a/asio/include/asio/basic_signal_set.hpp b/asio/include/asio/basic_signal_set.hpp
index 9282766..6b3a5d0 100644
--- a/asio/include/asio/basic_signal_set.hpp
+++ b/asio/include/asio/basic_signal_set.hpp
@@ -338,7 +338,7 @@
     return this->service.cancel(this->implementation, ec);
   }
 
-  // Start an asynchronous operation to wait for a signal to be delivered.
+  /// Start an asynchronous operation to wait for a signal to be delivered.
   /**
    * This function may be used to initiate an asynchronous wait against the
    * signal set. It always returns immediately.

asio/src/doc/reference.qbk

diff --git a/asio/src/doc/reference.qbk b/asio/src/doc/reference.qbk
index e51580c..6ee7a54 100644
--- a/asio/src/doc/reference.qbk
+++ b/asio/src/doc/reference.qbk
@@ -21801,7 +21801,7 @@
   
   [
     [[link asio.reference.basic_signal_set.async_wait [*async_wait]]]
-    []
+    [Start an asynchronous operation to wait for a signal to be delivered. ]
   ]
   
   [
@@ -22013,6 +22013,8 @@
 [section:async_wait basic_signal_set::async_wait]
 
 [indexterm2 async_wait..basic_signal_set] 
+Start an asynchronous operation to wait for a signal to be delivered. 
+
 
   template<
       typename ``[link asio.reference.SignalHandler SignalHandler]``>
@@ -75712,7 +75714,7 @@
   
   [
     [[link asio.reference.basic_signal_set.async_wait [*async_wait]]]
-    []
+    [Start an asynchronous operation to wait for a signal to be delivered. ]
   ]
   
   [