Run clang-format

source/listing_1.1.cpp

@@ -1,13 +1,15 @@
 #include <iostream>
 #include <thread>
 
-void hello()
+void
+hello()
 {
-    std::cout<<"Hello Concurrent World\n";
+  std::cout << "Hello Concurrent World\n";
 }
 
-int main()
+int
+main()
 {
-    std::thread t(hello);
-    t.join();
+  std::thread t(hello);
+  t.join();
 }