- /*
- $Revision: 1.9 $
- $Date: 2010/03/11 14:42:04 $
- $Author: faust $
- */
-
/*
* Copyright (c) 2001 by Peter Simons <simons@cryp.to>.
* All rights reserved.
// This is a wrapper class about variables where you want to keep
// track of whether it has been assigened yet or not.
-#include <iostream>
-
-template <typename varT>
+template <typename T>
class RESETABLE
{
- template <typename varT1>
- friend std::ostream & operator<<(std::ostream & o, RESETABLE<varT1> v);
public:
- typedef varT value_type;
+ typedef T value_type;
- //-------------------------------------------------------------------------
- RESETABLE()
- : value(),
- is_set(false)
- {
- }
- //-------------------------------------------------------------------------
- RESETABLE<value_type>(const RESETABLE<value_type> & rvalue)
- : value(rvalue.value),
- is_set(rvalue.is_set)
- {
- }
- //-------------------------------------------------------------------------
- RESETABLE(const value_type& val)
- : value(val),
- is_set(true)
- {
- }
- //-------------------------------------------------------------------------
- RESETABLE<value_type> & operator=(const RESETABLE<value_type> & rvalue)
- {
- value = rvalue.value;
- is_set = rvalue.is_set;
- return *this;
- }
- //-------------------------------------------------------------------------
- RESETABLE<value_type> & operator= (const value_type& rhs)
+ RESETABLE() : value(), is_set(false) {}
+ explicit RESETABLE(const T & v) : value(v), is_set(true) {}
+
+ RESETABLE<T> & operator=(const T & rhs)
{
value = rhs;
is_set = true;
return *this;
}
- //-------------------------------------------------------------------------
- const value_type& const_data() const throw()
- {
- return value;
- }
- //-------------------------------------------------------------------------
- value_type& data() throw()
- {
- return value;
- }
- //-------------------------------------------------------------------------
- operator const value_type&() const throw()
- {
- return value;
- }
- //-------------------------------------------------------------------------
- bool res_empty() const throw()
+
+ const T & const_data() const throw() { return value; }
+ T & data() throw() { return value; }
+ const T & data() const throw() { return value; }
+ bool empty() const throw() { return !is_set; }
+ void reset() throw() { is_set = false; }
+ void splice(const RESETABLE<T> & rhs)
{
- return !is_set;
+ if (rhs.is_set)
+ {
+ value = rhs.value;
+ is_set = true;
+ }
}
- //-------------------------------------------------------------------------
- void reset() throw()
+ void maybeSet(value_type& dest) const
{
- is_set = false;
+ if (is_set)
+ dest = value;
}
- //-------------------------------------------------------------------------
-protected:
- value_type value;
- bool is_set;
+
+private:
+ value_type value;
+ bool is_set;
};
-//-----------------------------------------------------------------------------
-template <typename varT>
-std::ostream & operator<<(std::ostream & o, RESETABLE<varT> v)
-{
- return o << v.value;
-}
-//-------------------------------------------------------------------------
-#endif // RESETABLE_VARIABLE_H
+#endif // RESETABLE_VARIABLE_H