see #2: move non-type template param auto to ch02

code/2/2.16.fold.expression.cpp

@@ -0,0 +1,16 @@
+//
+// 2.16.fold.expression.cpp
+// chapter 2 language usability
+// modern cpp tutorial
+//
+// created by changkun at changkun.de
+//
+
+#include <iostream>
+template<typename ... T>
+auto sum(T ... t) {
+    return (t + ...);
+}
+int main() {
+    std::cout << sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) << std::endl;
+}