support bazel complie this project and format code.

learn_class/modern_cpp_30/SFINAE/sfinae paper/auto.cpp

@@ -0,0 +1,26 @@
+//
+// Created by light on 20-1-6.
+//
+#include <iostream>
+
+bool f();
+
+auto test = f(); // Famous usage, auto deduced that test is a boolean, hurray!
+
+
+
+//                             vvv t wasn't declare at that point, it will be after as a parameter!
+template<typename T>
+decltype(t.serialize()) g(const T &t) {} // Compilation error
+
+// Less famous usage:
+//                    vvv auto delayed the return type specification!
+//                    vvv                vvv the return type is specified here and use t!
+template<typename T>
+auto g(const T &t) -> decltype(t.serialize()) {} // No compilation error.
+
+
+auto myFunction() // Automagically figures out that myFunction returns ints.
+{
+    return int();
+}