Variant

- Salvaged Variant code from older project, for use in expression
  evaluation.

src/Variant.h

@@ -0,0 +1,106 @@
+////////////////////////////////////////////////////////////////////////////////
+// taskwarrior - a command line task list manager.
+//
+// Copyright 2006 - 2011, Paul Beckingham, Federico Hernandez.
+// All rights reserved.
+//
+// This program is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation; either version 2 of the License, or (at your option) any later
+// version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+// details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program; if not, write to the
+//
+//     Free Software Foundation, Inc.,
+//     51 Franklin Street, Fifth Floor,
+//     Boston, MA
+//     02110-1301
+//     USA
+//
+////////////////////////////////////////////////////////////////////////////////
+#ifndef INCLUDED_VARIANT
+#define INCLUDED_VARIANT
+
+#include <string>
+#include <time.h>
+#include <Date.h>
+#include <Duration.h>
+
+class Variant
+{
+public:
+  enum variant_type
+  {
+    v_unknown,
+    v_boolean,
+    v_integer,
+    v_double,
+    v_string,
+    v_date,
+    v_duration,
+    v_other
+  };
+
+  Variant ();
+  Variant (const Variant&);
+  Variant (const bool);
+  Variant (const int);
+  Variant (const double&);
+  Variant (const std::string&);
+  Variant (const Date&);
+  Variant (const Duration&);
+
+  Variant& operator&& (const Variant& other);
+  Variant& operator|| (const Variant& other);
+  Variant& operator<= (const Variant& other);
+  Variant& operator>= (const Variant& other);
+  Variant& operator== (const Variant& other);
+  Variant& operator!= (const Variant& other);
+  Variant& operator^ (const Variant& other);
+  Variant& operator! ();
+  Variant& operator- (const Variant& other);
+  Variant& operator+ (const Variant& other);
+  Variant& operator* (const Variant& other);
+  Variant& operator/ (const Variant& other);
+  Variant& operator< (const Variant& other);
+  Variant& operator> (const Variant& other);
+
+  void sqrt  ();
+  void sin   ();
+  void cos   ();
+  void tan   ();
+  void asin  ();
+  void acos  ();
+  void atan  ();
+  void log   ();
+  void exp   ();
+  void exp10 ();
+  void ln    ();
+  void sign  ();
+  void abs   ();
+
+  void input (const std::string&);
+  std::string format ();
+  void cast (const variant_type);
+  variant_type type ();
+
+private:
+  variant_type mType;
+
+  bool mBool;
+  int mInteger;
+  double mDouble;
+  std::string mString;
+  Date mDate;
+  Duration mDuration;
+};
+
+#endif
+
+////////////////////////////////////////////////////////////////////////////////