//! \class SafeHandle
  //! Unique_ptr wrapper for WinAPI handles.
  class SafeHandle: public std::unique_ptr<std::remove_pointer<HANDLE>::type,void(*)( HANDLE )>
  {
    public:
      SafeHandle( HANDLE handle ): unique_ptr( handle, &SafeHandle::close )
      {
      }
      operator HANDLE()
      {
        return get();
      }
      const bool valid() const
      {
        return ( get() != INVALID_HANDLE_VALUE );
      }
    private:
      static void close( HANDLE handle )
      {
        if ( handle != INVALID_HANDLE_VALUE )
          CloseHandle( handle );
      }
  };