fix exit code of examples

example/cpp03/asymmetric/chaining.cpp

@@ -199,5 +199,7 @@ int main(int argc, char *argv[])
         }
     }
 
-    return 0;
+    std::cout << "\nDone" << std::endl;
+
+    return EXIT_SUCCESS;
 }

example/cpp03/asymmetric/layout.cpp

@@ -67,5 +67,7 @@ int main(int argc, char *argv[])
 
     std::copy(boost::begin(words), boost::end(words), boost::begin(writer));
 
-    return 0;
+    std::cout << "\nDone" << std::endl;
+
+    return EXIT_SUCCESS;
 }

example/cpp03/asymmetric/segmented_stack.cpp

@@ -63,5 +63,7 @@ int main( int argc, char * argv[])
 
     boost::thread( thread_fn).join();
 
+    std::cout << "Done" << std::endl;
+
     return 0;
 }