support bazel complie this project and format code.

cpp2.0/cpp11/variadic/variadic.cpp

@@ -0,0 +1,66 @@
+//
+// Created by light on 19-11-2.
+//
+
+// variadic template(c++11) 数量不定的模板参数
+#include <iostream>
+#include <vector>
+#include <tuple>
+
+using namespace std;
+// 参数个数  参数个数逐一递减
+// 参数类型  参数类型也逐一递减
+
+// (3)
+// 需要重载一个终止函数
+template<typename T>
+void _hash(size_t &seed, const T &val) {
+    cout << "hash over " << val << endl;
+}
+
+// (2)
+// 展开函数, 把参数分为一个普通参数和一个参数包，调用一次，参数包大小就减一
+template<typename T,typename... Args>
+void _hash(size_t &seed, const T& val,const Args &... args) {
+    cout << "parameter " << val<< endl;
+    // 递归调用自己
+    _hash(seed, args...);       // 上面如果不给T参数,会自己调用自己成死循环
+}
+
+
+// 泛化版 (1)
+template<typename ...Args>
+size_t _hash(const Args &... args) {
+    cout << "hash start " << endl;
+    size_t seed = 10;
+    // 递归调用自己
+    _hash(seed, args...);
+    return seed;
+}
+
+
+template<typename ...Args>
+class A {
+private:
+    int size = 0;    // c++11 支持类内初始化
+public:
+    A() {
+        size = sizeof...(Args);
+        cout << size << endl;
+    }
+};
+
+int main(void) {
+    size_t f = 10;
+    _hash("asdas", 2, 3, 4);
+    A<int, string, vector<int>> a;    // 类型任意
+
+    // Tuple就是利用这个特性(变长参数模板)
+    tuple<int, string> t = make_tuple(1, "hha");
+    int firstArg = get<0>(t);
+    string secondArg = get<1>(t);
+    cout << firstArg << " " << secondArg << endl;
+    return 0;
+}
+
+