Add Wallet header file

CM2005 Object Oriented Programming/Topic 5/5.1.3/Wallet.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <string>
+#include <map>
+
+class Wallet
+{
+  public:
+    Wallet();
+    /** insert currency to the wallet */
+    void insertCurrency(std::string type, double amount);
+
+    /** check if the wallet contains at least this much currency */
+    bool containsCurrency(std::string type, double amount);
+
+    /** generate a string representation of the wallet */
+    std::string toString();
+
+  private:
+    std::map<std::string, double> currencies;
+};