reactor: auto-initialization hooks

include/xo/reactor/Reactor.hpp

@@ -61,6 +61,9 @@ namespace xo {
              */
             void run() { this->run_n(-1); }
 
+        protected:
+            Reactor();
+
         private:
             /* control logging verbosity */
             log_level loglevel_;

include/xo/reactor/init_reactor.hpp

@@ -8,13 +8,13 @@
 #include "xo/subsys/Subsystem.hpp"
 
 namespace xo {
-  enum S_reactor_tag {};
+    enum S_reactor_tag {};
 
-  template<>
-  struct InitSubsys<S_reactor_tag> {
-    static void init();
-    static InitEvidence require();
-  };
+    template<>
+    struct InitSubsys<S_reactor_tag> {
+        static void init();
+        static InitEvidence require();
+    };
 } /*namespace xo*/
 
 /* end init_reactor.hpp */