/* -*- C++ -*-
 * src/lemon/error.h - Part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Combinatorial Optimization Research Group, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#ifndef LEMON_ERROR_H
#define LEMON_ERROR_H

//! \ingroup misc
//! \file
//! \brief Basic error handling (signaling) routines.

#include <exception>
#include <string>
#include <sstream>


namespace lemon {

  /**
   * \brief Generic exception class.
   *
   * \todo Do we need this?
   *
   * \todo Don't we need different kind of exceptions for different kind
   * of errors?
   * Shouldn't we use \<stdexcept\> instead?
   */
  class Exception : public std::exception {
  protected:
    std::ostringstream buf;
  public:
    Exception() {}
    explicit Exception(const std::string &s) { buf << s; }
    Exception(const Exception &e) : std::exception() {
      buf << e.buf.str();
    }
    virtual ~Exception() throw() {}
    
    virtual const char* what() const throw() {
      return buf.str().c_str();
    }

    template <typename T>
    Exception& operator<<(T const& t) { buf << t; return *this; }
  };

  /**
   * \brief Generic error signaling function.
   *
   * \todo Do we really need this? Is it helpful?
   */
  inline void fault(const std::string &msg) {
    throw Exception(msg);
  }

  /**
   * \brief Macro for mark not yet implemented features.
   *
   * \todo Is this the right place for this? It should be used only in
   * modules under development.
   */

# define FIXME(msg) \
    do { throw ::lemon::Exception() << "FIXME: " msg " (in: "    \
      __FILE__ ", " << __LINE__ << ")";                          \
    } while(false)

}
#endif // LEMON_ERROR_H