Put back the event::signal() member. The asio::detail::event class seems to be being used by other projects, so we'll keep the old function name to avoid unnecessary breakage.

diff --git a/asio/include/asio/detail/null_event.hpp b/asio/include/asio/detail/null_event.hpp
index 987fb67..4470a1f 100644
--- a/asio/include/asio/detail/null_event.hpp
+++ b/asio/include/asio/detail/null_event.hpp

@@ -40,6 +40,12 @@
   {
   }
 
+  // Signal the event. (Retained for backward compatibility.)
+  template <typename Lock>
+  void signal(Lock&)
+  {
+  }
+
   // Signal all waiters.
   template <typename Lock>
   void signal_all(Lock&)

diff --git a/asio/include/asio/detail/posix_event.hpp b/asio/include/asio/detail/posix_event.hpp
index 7ca1b1b..14ec89d 100644
--- a/asio/include/asio/detail/posix_event.hpp
+++ b/asio/include/asio/detail/posix_event.hpp

@@ -41,6 +41,13 @@
     ::pthread_cond_destroy(&cond_);
   }
 
+  // Signal the event. (Retained for backward compatibility.)
+  template <typename Lock>
+  void signal(Lock& lock)
+  {
+    this->signal_all(lock);
+  }
+
   // Signal all waiters.
   template <typename Lock>
   void signal_all(Lock& lock)

diff --git a/asio/include/asio/detail/win_event.hpp b/asio/include/asio/detail/win_event.hpp
index d3352d5..b73abbd 100644
--- a/asio/include/asio/detail/win_event.hpp
+++ b/asio/include/asio/detail/win_event.hpp

@@ -38,6 +38,13 @@
   // Destructor.
   ASIO_DECL ~win_event();
 
+  // Signal the event. (Retained for backward compatibility.)
+  template <typename Lock>
+  void signal(Lock& lock)
+  {
+    this->signal_all(lock);
+  }
+
   // Signal all waiters.
   template <typename Lock>
   void signal_all(Lock& lock)