添加设计模式及例子，包括：单例、抽象工厂、适配器、桥接、观察者模式

DesignPattern/SingletonPattern/Singleton.h

@@ -0,0 +1,25 @@
+//
+// Created by xiemenghui on 2018/7/20.
+//
+
+#ifndef DESIGNPATTERN_SINGLETON_H
+#define DESIGNPATTERN_SINGLETON_H
+
+// 单例模式
+class Singleton {
+private:
+    Singleton(){}
+    ~Singleton(){}
+    Singleton(const Singleton &);
+    Singleton & operator= (const Singleton &);
+
+public:
+    static Singleton & GetInstance()
+    {
+        static Singleton instance;
+        return instance;
+    }
+    void DoSomething();
+};
+
+#endif //DESIGNPATTERN_SINGLETON_H