Add answer for ex_16_52

Add answer for ex_16_52

ch16/ex16_52_variadic_template.cpp

@@ -0,0 +1,28 @@
+#include <iostream>
+#include <string>
+
+using std::string;
+using std::cout;
+using std::endl;
+
+template <typename T, typename ... Args>
+void foo(const T & t, const Args& ... rest)
+{
+    cout << "sizeof...(Args): " << sizeof...(Args) << endl;
+    cout << "sizeof...(rest): " << sizeof...(rest) << endl;
+}
+
+int main()
+{
+    int i = 0;
+    double d = 3.14;
+    string s = "how now brown cow";
+    cout << "foo(i, s, 42, d) : " << endl;
+    foo(i, s, 42, d);
+    cout << "foo(s, 42, \"hi\") : " << endl;
+    foo(s, 42, "hi");
+    cout << "foo(d, s) : " << endl;
+    foo(d, s);
+    cout << "foo(\"hi\") : " << endl;
+    foo("hi"); 
+}