Exception_Handler.hpp

#ifndef Exc_Ruby__detail__Exception_Handler__hpp_
#define Exc_Ruby__detail__Exception_Handler__hpp_

#include "ruby.h"

namespace Exc_Ruby
{

namespace detail
{

class Exception_Handler
{
public:
  Exception_Handler(Exception_Handler const * next_exception_handler)
    : next_exception_handler_(next_exception_handler)
  {
  }

  virtual ~Exception_Handler()
  {
  }

  virtual VALUE handle_exception() const = 0;

  VALUE call_next_exception_handler() const
  {
    return next_exception_handler_->handle_exception();
  }

private:
  Exception_Handler const * next_exception_handler_;
};

class Default_Exception_Handler
  : public Exception_Handler
{
public:
  Default_Exception_Handler()
    : Exception_Handler(0)
  {
  }

  virtual VALUE handle_exception() const
  {
    throw;
  }
};

template <typename Exception_T, typename Functor_T>
class Functor_Exception_Handler
  : public Exception_Handler
{
public:
  Functor_Exception_Handler(
      Functor_T handler,
      Exception_Handler const * next_exception_handler)
    : Exception_Handler(next_exception_handler)
    , handler_(handler)
  {
  }

private:
  virtual VALUE handle_exception() const
  {
    try
    {
      return call_next_exception_handler();
    }
    catch(Exception_T const & ex)
    {
      handler_(ex);
      throw;
    }
  }

private:
  Functor_T handler_;
};

} // namespace detail

} // namespace Exc_Ruby

#endif // Exc_Ruby__detail__Exception_Handler__hpp_

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