TemporaryAssignment.hpp

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// Torc - Copyright 2011-2013 University of Southern California.  All Rights Reserved.
// $HeadURL$
// $Id$

// 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 3 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, see <http://www.gnu.org/licenses/>.

/// \file
/// \brief Header for the TemporaryAssignment class.

#ifndef TORC_GENERIC_VERILOG_TEMPORARYASSIGNMENT_HPP
#define TORC_GENERIC_VERILOG_TEMPORARYASSIGNMENT_HPP

namespace torc {
namespace generic {

    /// \brief Template class that stores the current value of a variable and restores that value 
    ///     when this object goes out of scope.
    /// \note This class inspired a StackOverflow question, and there may be more general ways to 
    ///     solve the problem.
    /// \see http://stackoverflow.com/questions/13383683/reverting-temporary-assignment-in-c
    template <typename TYPE> class TemporaryAssignment {
    protected:
    // members
        /// \brief Reference to the variable.
        TYPE& mVariable;
        /// \brief Original value of the variable
        TYPE mOriginalValue;
    public:
    // constructors
        /// \brief Public constructor that does not assign a new value.
        /// \param inVariable The variable to save and restore.
        TemporaryAssignment(TYPE& inVariable) 
            : mVariable(inVariable), mOriginalValue(inVariable) {
        }
        /// \brief Public constructor that assigns a new value
        /// \param inVariable The variable to save and restore.
        /// \param inValue The new value to use.
        TemporaryAssignment(TYPE& inVariable, TYPE inValue) 
            : mVariable(inVariable), mOriginalValue(inVariable) {
            mVariable = inValue;
        }
        /// \brief Public destructor to restore the original value.
        ~TemporaryAssignment(void) {
            mVariable = mOriginalValue;
        }
    };

} // namespace generic
} // namespace torc

#endif // TORC_GENERIC_VERILOG_TEMPORARYASSIGNMENT_HPP