First checkin for OpenMesh 2.0

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@2 fdac6126-5c0c-442c-9429-916003d36597

Apps/Decimating/CmdOption.hh

@@ -0,0 +1,56 @@
+#ifndef CMDOPTION
+#define CMDOPTION
+
+template <typename T>
+class CmdOption
+{
+public:
+
+  typedef T value_type;
+
+  CmdOption(const T& _val) : val_(_val), valid_(true) { }
+  CmdOption() : valid_(false), enabled_(false) { }
+
+  // has been set and has a value
+  bool is_valid(void) const   { return valid_;   }
+  bool has_value(void) const  { return is_valid(); }
+
+  // has been set and may have an value (check with is_valid())
+  bool is_enabled() const { return enabled_; }
+
+  void enable() { enabled_ = true; }
+
+  CmdOption& operator = ( const T& _val ) 
+  { 
+    val_ = _val;
+    valid_=true; 
+    enable();
+    return *this; 
+  }
+
+  operator T  () { return val_; }
+  //  operator const T& () const { return val_; }
+
+  operator T* () { return is_valid() ? &val_ : NULL; }
+
+private:
+
+  T    val_;
+  bool valid_;
+  bool enabled_;
+
+private: // non-copyable
+  
+  CmdOption(const CmdOption&);
+  CmdOption& operator = ( const CmdOption& );
+
+};
+
+template < typename T >
+std::ostream& operator << ( std::ostream& _os, CmdOption<T>& _opt )
+{
+  _os << (T&)_opt;
+  return _os;
+}
+
+#endif