support bazel complie this project and format code.

learn_class/modern_cpp_30/container2/unorder.cpp

@@ -0,0 +1,31 @@
+//
+// Created by light on 19-12-16.
+//
+
+#include "../container1/output_container.h"
+#include <complex>       // std::complex
+#include <iostream>      // std::cout/endl
+#include <unordered_map> // std::unordered_map
+#include <unordered_set> // std::unordered_set
+
+using namespace std;
+
+namespace std {
+
+template <typename T> struct hash<complex<T>> {
+  size_t operator()(const complex<T> &v) const noexcept {
+    hash<T> h;
+    return h(v.real()) + h(v.imag());
+  }
+};
+
+} // namespace std
+
+int main() {
+  unordered_set<int> s{1, 1, 2, 3, 5, 8, 13, 21};
+  cout << s << endl;
+
+  unordered_map<complex<double>, double> umc{{{1.0, 1.0}, 1.4142},
+                                             {{3.0, 4.0}, 5.0}};
+  cout << umc << endl;
+}