text: // -*- Mode: c++; c-basic-offset: 4; tab-width: 4; -*-
  
  /******************************************************************************
   *
   *  file:  ValueArg.h
   *
   *  Copyright (c) 2003, Michael E. Smoot .
   *  Copyright (c) 2004, Michael E. Smoot, Daniel Aarno.
   *  All rights reverved.
   *
   *  See the file COPYING in the top directory of this distribution for
   *  more information.
   *
   *  THE SOFTWARE IS PROVIDED _AS IS_, WITHOUT WARRANTY OF ANY KIND, EXPRESS
   *  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   *  DEALINGS IN THE SOFTWARE.
   *
   *****************************************************************************/
  
  #ifndef TCLAP_VALUE_ARGUMENT_H
  #define TCLAP_VALUE_ARGUMENT_H
  
  #include <string>
  #include <vector>
  
  #include <tclap/Arg.h>
  #include <tclap/Constraint.h>
  
  namespace TCLAP {
  
  /**
   * The basic labeled argument that parses a value.
   * This is a template class, which means the type T defines the type
   * that a given object will attempt to parse when the flag/name is matched
   * on the command line.  While there is nothing stopping you from creating
   * an unflagged ValueArg, it is unwise and would cause significant problems.
   * Instead use an UnlabeledValueArg.
   */
  template <class T>
  class ValueArg : public Arg {
  protected:
      /**
       * The value parsed from the command line.
       * Can be of any type, as long as the >> operator for the type
       * is defined.
       */
      T _value;
  
      /**
       * Used to support the reset() method so that ValueArg can be
       * reset to their constructed value.
       */
      T _default;
  
      /**
       * A human readable description of the type to be parsed.
       * This is a hack, plain and simple.  Ideally we would use RTTI to
       * return the name of type T, but until there is some sort of
       * consistent support for human readable names, we are left to our
       * own devices.
       */
      std::string _typeDesc;
  
      /**
       * A Constraint this Arg must conform to.
       */
      Constraint<T>* _constraint;
  
      /**
       * Extracts the value from the string.
       * Attempts to parse string as type T, if this fails an exception
       * is thrown.
       * \param val - value to be parsed.
       */
      void _extractValue(const std::string& val);
  
  public:
      /**
       * Labeled ValueArg constructor.
       * You could conceivably call this constructor with a blank flag,
       * but that would make you a bad person.  It would also cause
       * an exception to be thrown.   If you want an unlabeled argument,
       * use the other constructor.
       * \param flag - The one character flag that identifies this
       * argument on the command line.
       * \param name - A one word name for the argument.  Can be
       * used as a long flag on the command line.
       * \param desc - A description of what the argument is for or
       * does.
       * \param req - Whether the argument is required on the command
       * line.
       * \param value - The default value assigned to this argument if it
       * is not present on the command line.
       * \param typeDesc - A short, human readable description of the
       * type that this object expects.  This is used in the generation
       * of the USAGE statement.  The goal is to be helpful to the end user
       * of the program.
       * \param v - An optional visitor.  You probably should not
       * use this unless you have a very good reason.
       */
      ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T value,
          const std::string& typeDesc, Visitor* v = NULL);
  
      /**
       * Labeled ValueArg constructor.
       * You could conceivably call this constructor with a blank flag,
       * but that would make you a bad person.  It would also cause
       * an exception to be thrown.   If you want an unlabeled argument,
       * use the other constructor.
       * \param flag - The one character flag that identifies this
       * argument on the command line.
       * \param name - A one word name for the argument.  Can be
       * used as a long flag on the command line.
       * \param desc - A description of what the argument is for or
       * does.
       * \param req - Whether the argument is required on the command
       * line.
       * \param value - The default value assigned to this argument if it
       * is not present on the command line.
       * \param typeDesc - A short, human readable description of the
       * type that this object expects.  This is used in the generation
       * of the USAGE statement.  The goal is to be helpful to the end user
       * of the program.
       * \param parser - A CmdLine parser object to add this Arg to
       * \param v - An optional visitor.  You probably should not
       * use this unless you have a very good reason.
       */
      ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T value,
          const std::string& typeDesc, CmdLineInterface& parser, Visitor* v = NULL);
  
      /**
       * Labeled ValueArg constructor.
       * You could conceivably call this constructor with a blank flag,
       * but that would make you a bad person.  It would also cause
       * an exception to be thrown.   If you want an unlabeled argument,
       * use the other constructor.
       * \param flag - The one character flag that identifies this
       * argument on the command line.
       * \param name - A one word name for the argument.  Can be
       * used as a long flag on the command line.
       * \param desc - A description of what the argument is for or
       * does.
       * \param req - Whether the argument is required on the command
       * line.
       * \param value - The default value assigned to this argument if it
       * is not present on the command line.
       * \param constraint - A pointer to a Constraint object used
               * to constrain this Arg.
       * \param parser - A CmdLine parser object to add this Arg to.
       * \param v - An optional visitor.  You probably should not
       * use this unless you have a very good reason.
       */
      ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T value,
          Constraint<T>* constraint, CmdLineInterface& parser, Visitor* v = NULL);
  
      /**
       * Labeled ValueArg constructor.
       * You could conceivably call this constructor with a blank flag,
       * but that would make you a bad person.  It would also cause
       * an exception to be thrown.   If you want an unlabeled argument,
       * use the other constructor.
       * \param flag - The one character flag that identifies this
       * argument on the command line.
       * \param name - A one word name for the argument.  Can be
       * used as a long flag on the command line.
       * \param desc - A description of what the argument is for or
       * does.
       * \param req - Whether the argument is required on the command
       * line.
       * \param value - The default value assigned to this argument if it
       * is not present on the command line.
       * \param constraint - A pointer to a Constraint object used
               * to constrain this Arg.
       * \param v - An optional visitor.  You probably should not
       * use this unless you have a very good reason.
       */
      ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T value,
          Constraint<T>* constraint, Visitor* v = NULL);
  
      /**
       * Handles the processing of the argument.
       * This re-implements the Arg version of this method to set the
       * _value of the argument appropriately.  It knows the difference
       * between labeled and unlabeled.
       * \param i - The current argument in the list.
       * \param args - Mutable list of strings. Passed
       * in from main().
       */
      virtual bool processArg(std::size_t* i, std::vector<std::string>& args);
  
      /**
       * Returns the value of the argument.
       */
      T& getValue();
  
      /**
       * Specialization of shortID.
       * \param val - value to be used.
       */
      virtual std::string shortID(const std::string& val = "val") const;
  
      /**
       * Specialization of longID.
       * \param val - value to be used.
       */
      virtual std::string longID(const std::string& val = "val") const;
  
      virtual void reset();
  
  private:
      /**
       * Prevent accidental copying
       */
      ValueArg<T>(const ValueArg<T>& rhs);
      ValueArg<T>& operator=(const ValueArg<T>& rhs);
  };
  
  /**
   * Constructor implementation.
   */
  template <class T>
  ValueArg<T>::ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T val,
      const std::string& typeDesc, Visitor* v)
    : Arg(flag, name, desc, req, true, v)
    , _value(val)
    , _default(val)
    , _typeDesc(typeDesc)
    , _constraint(NULL)
  {
  }
  
  template <class T>
  ValueArg<T>::ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T val,
      const std::string& typeDesc, CmdLineInterface& parser, Visitor* v)
    : Arg(flag, name, desc, req, true, v)
    , _value(val)
    , _default(val)
    , _typeDesc(typeDesc)
    , _constraint(NULL)
  {
      parser.add(this);
  }
  
  template <class T>
  ValueArg<T>::ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T val,
      Constraint<T>* constraint, Visitor* v)
    : Arg(flag, name, desc, req, true, v)
    , _value(val)
    , _default(val)
    , _typeDesc(constraint->shortID())
    , _constraint(constraint)
  {
  }
  
  template <class T>
  ValueArg<T>::ValueArg(const std::string& flag, const std::string& name, const std::string& desc, bool req, T val,
      Constraint<T>* constraint, CmdLineInterface& parser, Visitor* v)
    : Arg(flag, name, desc, req, true, v)
    , _value(val)
    , _default(val)
    , _typeDesc(constraint->shortID())
    , _constraint(constraint)
  {
      parser.add(this);
  }
  
  /**
   * Implementation of getValue().
   */
  template <class T>
  T& ValueArg<T>::getValue()
  {
      return _value;
  }
  
  /**
   * Implementation of processArg().
   */
  template <class T>
  bool ValueArg<T>::processArg(std::size_t* i, std::vector<std::string>& args)
  {
      if (_ignoreable && Arg::ignoreRest())
          return false;
  
      if (_hasBlanks(args[*i]))
          return false;
  
      std::string flag = args[*i];
  
      std::string value = "";
      trimFlag(flag, value);
  
      if (argMatches(flag)) {
          if (_alreadySet) {
              if (_xorSet)
                  throw(CmdLineParseException("Mutually exclusive argument already set!", toString()));
              else
                  throw(CmdLineParseException("Argument already set!", toString()));
          }
  
          if (Arg::delimiter() != ' ' && value == "")
              throw(ArgParseException("Couldn't find delimiter for this argument!", toString()));
  
          if (value == "") {
              if (++(*i) < args.size())
                  _extractValue(args[*i]);
              else
                  throw(ArgParseException("Missing a value for this argument!", toString()));
          } else
              _extractValue(value);
  
          _alreadySet = true;
          _checkWithVisitor();
          return true;
      } else
          return false;
  }
  
  /**
   * Implementation of shortID.
   */
  template <class T>
  std::string ValueArg<T>::shortID(const std::string& val) const
  {
      static_cast<void>(val); // Ignore input, don't warn
      return Arg::shortID(_typeDesc);
  }
  
  /**
   * Implementation of longID.
   */
  template <class T>
  std::string ValueArg<T>::longID(const std::string& val) const
  {
      static_cast<void>(val); // Ignore input, don't warn
      return Arg::longID(_typeDesc);
  }
  
  template <class T>
  void ValueArg<T>::_extractValue(const std::string& val)
  {
      try {
          ExtractValue(_value, val, typename ArgTraits<T>::ValueCategory());
      } catch (ArgParseException& e) {
          throw ArgParseException(e.error(), toString());
      }
  
      if (_constraint != NULL)
          if (!_constraint->check(_value))
              throw(CmdLineParseException(
                  "Value '" + val + +"' does not meet constraint: " + _constraint->description(), toString()));
  }
  
  template <class T>
  void ValueArg<T>::reset()
  {
      Arg::reset();
      _value = _default;
  }
  
  } // namespace TCLAP
  
  #endif
  