JTypeInfo.hh

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#ifndef __JLANG__JTYPEINFO__
#define __JLANG__JTYPEINFO__

#include <typeinfo>

#include "JLang/JComparable.hh"
#include "JLang/JException.hh"


/**
 * \author mdejong
 */

namespace JLANG {}
namespace JPP { using namespace JLANG; }

namespace JLANG {


  /**
   * This class is a wrapper around the STL type_info class.
   * It is possible to create a list of objects of this class.
   *
   * Source code is taken from reference:
   * A. Alexandrescu, Modern C++ Design, Addison Wesley.
   */
  class JTypeInfo :
    public JComparable<JTypeInfo>
  {
  public:
    /**
     * Default constructor.
     */
    JTypeInfo()
    {
      class JNullType {};

      pType = &typeid(JNullType);
    }


    /**
     * Constructor.
     *
     * \param  type      type information
     */
    JTypeInfo(const std::type_info& type) :
      pType(&type)
    {}
 

    /**
     * Get type information.
     *
     * \return           type information
     */
    const std::type_info& get() const
    {
      if (pType == NULL)
        throw JTypeInformationException("No type information.");
      else
        return *pType;
    }


    /**
     * Less than operation.
     *
     * \param  that      object to be compared
     * \return           true if this type information less than that type information; else false
     */
    bool less(const JTypeInfo& that) const 
    {
      return get().before(that.get()) != 0;
    }


    /**
     * Evaluate order.
     *
     * \param  type     type information
     * \return          true if this type before given type; else false
     */
    bool before(const JTypeInfo& type) const
    {
      return get().before(type.get()) != 0;
    }
     

    /**
     * Get type name.
     *
     * \return           type name
     */
    const char* name() const
    {
      return get().name();
    }


  private:
    const std::type_info* pType;
  };
}

#endif