błąd: using namespace std

pomocy, nie wiem dlaczego ale gdy włączam (w codeblocks) kod hello world program pokazuje mi to:

"
// <memory> Forward declarations -*- C++ -*-

// Copyright (C) 2001-2015 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/*
 * Copyright (c) 1996-1997
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

/** @file bits/memoryfwd.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{memory}
 */

#ifndef _MEMORYFWD_H
#define _MEMORYFWD_H 1

#pragma GCC system_header

#include <bits/c++config.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   * @defgroup allocators Allocators
   * @ingroup memory
   *
   * Classes encapsulating memory operations.
   *
   * @{
   */

  template<typename>
    class allocator;

  template<>
    class allocator<void>;

  /// Declare uses_allocator so it can be specialized in \<queue\> etc.
  template<typename, typename>
    struct uses_allocator;

  /// @} group memory

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#endif
"

jestem początkujący i zbyt dobrze sie nie znam jeszcze na codeblocks, proszę o pomoc :(

A kod i treść błędu?