if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * 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.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996
 * 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 ext/algorithm
 *  This file is a GNU extension to the Standard C++ Library (possibly
 *  containing extensions from the HP/SGI STL subset).
 */

#ifndef _EXT_ALGORITHM
#define _EXT_ALGORITHM 1

#pragma GCC system_header

#include <algorithm>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  using std::ptrdiff_t;
  using std::min;
  using std::pair;
  using std::input_iterator_tag;
  using std::random_access_iterator_tag;
  using std::iterator_traits;

  //--------------------------------------------------
  // copy_n (not part of the C++ standard)

  template<typename _InputIterator, typename _Size, typename _OutputIterator>
    pair<_InputIterator, _OutputIterator>
    __copy_n(_InputIterator __first, _Size __count,
	     _OutputIterator __result,
	     input_iterator_tag)
    {
      for ( ; __count > 0; --__count)
	{
	  *__result = *__first;
	  ++__first;
	  ++__result;
	}
      return pair<_InputIterator, _OutputIterator>(__first, __result);
    }

  template<typename _RAIterator, typename _Size, typename _OutputIterator>
    inline pair<_RAIterator, _OutputIterator>
    __copy_n(_RAIterator __first, _Size __count,
	     _OutputIterator __result,
	     random_access_iterator_tag)
    {
      _RAIterator __last = __first + __count;
      return pair<_RAIterator, _OutputIterator>(__last, std::copy(__first,
								  __last,
								  __result));
    }

  /**
   *  @brief Copies the range [first,first+count) into [result,result+count).
   *  @param  first  An input iterator.
   *  @param  count  The number of elements to copy.
   *  @param  result An output iterator.
   *  @return   A std::pair composed of first+count and result+count.
   *
   *  This is an SGI extension.
   *  This inline function will boil down to a call to @c memmove whenever
   *  possible.  Failing that, if random access iterators are passed, then the
   *  loop count will be known (and therefore a candidate for compiler
   *  optimizations such as unrolling).
   *  @ingroup SGIextensions
  */
  template<typename _InputIterator, typename _Size, typename _OutputIterator>
    inline pair<_InputIterator, _OutputIterator>
    copy_n(_InputIterator __first, _Size __count, _OutputIterator __result)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
	    typename iterator_traits<_InputIterator>::value_type>)

      return __copy_n(__first, __count, __result,
		      std::__iterator_category(__first));
    }

  template<typename _InputIterator1, typename _InputIterator2>
    int
    __lexicographical_compare_3way(_InputIterator1 __first1,
				   _InputIterator1 __last1,
				   _InputIterator2 __first2,
				   _InputIterator2 __last2)
    {
      while (__first1 != __last1 && __first2 != __last2)
	{
	  if (*__first1 < *__first2)
	    return -1;
	  if (*__first2 < *__first1)
	    return 1;
	  ++__first1;
	  ++__first2;
	}
      if (__first2 == __last2)
	return !(__first1 == __last1);
      else
	return -1;
    }

  inline int
  __lexicographical_compare_3way(const unsigned char* __first1,
				 const unsigned char* __last1,
				 const unsigned char* __first2,
				 const unsigned char* __last2)
  {
    const ptrdiff_t __len1 = __last1 - __first1;
    const ptrdiff_t __len2 = __last2 - __first2;
    const int __result = __builtin_memcmp(__first1, __first2,
					  min(__len1, __len2));
    return __result != 0 ? __result
			 : (__len1 == __len2 ? 0 : (__len1 < __len2 ? -1 : 1));
  }

  inline int
  __lexicographical_compare_3way(const char* __first1, const char* __last1,
				 const char* __first2, const char* __last2)
  {
#if CHAR_MAX == SCHAR_MAX
    return __lexicographical_compare_3way((const signed char*) __first1,
					  (const signed char*) __last1,
					  (const signed char*) __first2,
					  (const signed char*) __last2);
#else
    return __lexicographical_compare_3way((const unsigned char*) __first1,
					  (const unsigned char*) __last1,
					  (const unsigned char*) __first2,
					  (const unsigned char*) __last2);
#endif
  }

  /**
   *  @brief @c memcmp on steroids.
   *  @param  first1  An input iterator.
   *  @param  last1   An input iterator.
   *  @param  first2  An input iterator.
   *  @param  last2   An input iterator.
   *  @return   An int, as with @c memcmp.
   *
   *  The return value will be less than zero if the first range is
   *  "lexigraphically less than" the second, greater than zero if the second
   *  range is "lexigraphically less than" the first, and zero otherwise.
   *  This is an SGI extension.
   *  @ingroup SGIextensions
  */
  template<typename _InputIterator1, typename _InputIterator2>
    int
    lexicographical_compare_3way(_InputIterator1 __first1,
				 _InputIterator1 __last1,
				 _InputIterator2 __first2,
				 _InputIterator2 __last2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_function_requires(_LessThanComparableConcept<
	    typename iterator_traits<_InputIterator1>::value_type>)
      __glibcxx_function_requires(_LessThanComparableConcept<
	    typename iterator_traits<_InputIterator2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      return __lexicographical_compare_3way(__first1, __last1, __first2,
					    __last2);
    }

  // count and count_if: this version, whose return type is void, was present
  // in the HP STL, and is retained as an extension for backward compatibility.
  template<typename _InputIterator, typename _Tp, typename _Size>
    void
    count(_InputIterator __first, _InputIterator __last,
	  const _Tp& __value,
	  _Size& __n)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_EqualityComparableConcept<
	    typename iterator_traits<_InputIterator>::value_type >)
      __glibcxx_function_requires(_EqualityComparableConcept<_Tp>)
      __glibcxx_requires_valid_range(__first, __last);

      for ( ; __first != __last; ++__first)
	if (*__first == __value)
	  ++__n;
    }

  template<typename _InputIterator, typename _Predicate, typename _Size>
    void
    count_if(_InputIterator __first, _InputIterator __last,
	     _Predicate __pred,
	     _Size& __n)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
	    typename iterator_traits<_InputIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      for ( ; __first != __last; ++__first)
	if (__pred(*__first))
	  ++__n;
    }

  // random_sample and random_sample_n (extensions, not part of the standard).

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _ForwardIterator, typename _OutputIterator,
	   typename _Distance>
    _OutputIterator
    random_sample_n(_ForwardIterator __first, _ForwardIterator __last,
                    _OutputIterator __out, const _Distance __n)
    {
      // concept requirements
      __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
      __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
		typename iterator_traits<_ForwardIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      _Distance __remaining = std::distance(__first, __last);
      _Distance __m = min(__n, __remaining);

      while (__m > 0)
	{
	  if ((std::rand() % __remaining) < __m)
	    {
	      *__out = *__first;
	      ++__out;
	      --__m;
	    }
	  --__remaining;
	  ++__first;
	}
      return __out;
    }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _ForwardIterator, typename _OutputIterator,
	   typename _Distance, typename _RandomNumberGenerator>
    _OutputIterator
    random_sample_n(_ForwardIterator __first, _ForwardIterator __last,
                   _OutputIterator __out, const _Distance __n,
		   _RandomNumberGenerator& __rand)
    {
      // concept requirements
      __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
      __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
		typename iterator_traits<_ForwardIterator>::value_type>)
      __glibcxx_function_requires(_UnaryFunctionConcept<
		_RandomNumberGenerator, _Distance, _Distance>)
      __glibcxx_requires_valid_range(__first, __last);

      _Distance __remaining = std::distance(__first, __last);
      _Distance __m = min(__n, __remaining);

      while (__m > 0)
	{
	  if (__rand(__remaining) < __m)
	    {
	      *__out = *__first;
	      ++__out;
	      --__m;
	    }
	  --__remaining;
	  ++__first;
	}
      return __out;
    }

  template<typename _InputIterator, typename _RandomAccessIterator,
	   typename _Distance>
    _RandomAccessIterator
    __random_sample(_InputIterator __first, _InputIterator __last,
		    _RandomAccessIterator __out,
		    const _Distance __n)
    {
      _Distance __m = 0;
      _Distance __t = __n;
      for ( ; __first != __last && __m < __n; ++__m, ++__first)
	__out[__m] = *__first;

      while (__first != __last)
	{
	  ++__t;
	  _Distance __M = std::rand() % (__t);
	  if (__M < __n)
	    __out[__M] = *__first;
	  ++__first;
	}
      return __out + __m;
    }

  template<typename _InputIterator, typename _RandomAccessIterator,
	   typename _RandomNumberGenerator, typename _Distance>
    _RandomAccessIterator
    __random_sample(_InputIterator __fi1
11111rst, _InputIterator __last,
		    _RandomAccessIterator __out,
		    _RandomNumberGenerator& __rand,
		    const _Distance __n)
    {
      // concept requirements
      __glibcxx_function_requires(_UnaryFunctionConcept<
	    _RandomNumberGenerator, _Distance, _Distance>)

      _Distance __m = 0;
      _Distance __t = __n;
      for ( ; __first != __last && __m < __n; ++__m, ++__first)
	__out[__m] = *__first;

      while (__first != __last)
	{
	  ++__t;
	  _Distance __M = __rand(__t);
	  if (__M < __n)
	    __out[__M] = *__first;
	  ++__first;
	}
      return __out + __m;
    }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _InputIterator, typename _RandomAccessIterator>
    inline _RandomAccessIterator
    random_sample(_InputIterator __first, _InputIterator __last,
		  _RandomAccessIterator __out_first,
		  _RandomAccessIterator __out_last)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
	    _RandomAccessIterator>)
      __glibcxx_requires_valid_range(__first, __last);
      __glibcxx_requires_valid_range(__out_first, __out_last);

      return __random_sample(__first, __last,
			     __out_first, __out_last - __out_first);
    }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _InputIterator, typename _RandomAccessIterator,
	   typename _RandomNumberGenerator>
    inline _RandomAccessIterator
    random_sample(_InputIterator __first, _InputIterator __last,
		  _RandomAccessIterator __out_first,
		  _RandomAccessIterator __out_last,
		  _RandomNumberGenerator& __rand)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
	    _RandomAccessIterator>)
      __glibcxx_requires_valid_range(__first, __last);
      __glibcxx_requires_valid_range(__out_first, __out_last);

      return __random_sample(__first, __last,
			     __out_first, __rand,
			     __out_last - __out_first);
    }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
  using std::is_heap;
  using std::is_sorted;
#else
  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _RandomAccessIterator>
    inline bool
    is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
    {
      // concept requirements
      __glibcxx_function_requires(_RandomAccessIteratorConcept<
				  _RandomAccessIterator>)
      __glibcxx_function_requires(_LessThanComparableConcept<
	    typename iterator_traits<_RandomAccessIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      return std::__is_heap(__first, __last - __first);
    }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _RandomAccessIterator, typename _StrictWeakOrdering>
    inline bool
    is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last,
	    _StrictWeakOrdering __comp)
    {
      // concept requirements
      __glibcxx_function_requires(_RandomAccessIteratorConcept<
				  _RandomAccessIterator>)
      __glibcxx_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
	    typename iterator_traits<_RandomAccessIterator>::value_type,
	    typename iterator_traits<_RandomAccessIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      return std::__is_heap(__first, __comp, __last - __first);
    }

  // is_sorted, a predicated testing whether a range is sorted in
  // nondescending order.  This is an extension, not part of the C++
  // standard.

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _ForwardIterator>
    bool
    is_sorted(_ForwardIterator __first, _ForwardIterator __last)
    {
      // concept requirements
      __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
      __glibcxx_function_requires(_LessThanComparableConcept<
	    typename iterator_traits<_ForwardIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      if (__first == __last)
	return true;

      _ForwardIterator __next = __first;
      for (++__next; __next != __last; __first = __next, ++__next)
	if (*__next < *__first)
	  return false;
      return true;
    }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _ForwardIterator, typename _StrictWeakOrdering>
    bool
    is_sorted(_ForwardIterator __first, _ForwardIterator __last,
	      _StrictWeakOrdering __comp)
    {
      // concept requirements
      __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
      __glibcxx_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
	    typename iterator_traits<_ForwardIterator>::value_type,
	    typename iterator_traits<_ForwardIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      if (__first == __last)
	return true;

      _ForwardIterator __next = __first;
      for (++__next; __next != __last; __first = __next, ++__next)
	if (__comp(*__next, *__first))
	  return false;
      return true;
    }
#endif

_GLIBCXX_END_NAMESPACE

#endif /* _EXT_ALGORITHM */
// array allocator -*- C++ -*-

// Copyright (C) 2004, 2005, 2006, 2007 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/** @file ext/array_allocator.h
 *  This file is a GNU extension to the Standard C++ Library.
 */

#ifndef _ARRAY_ALLOCATOR_H
#define _ARRAY_ALLOCATOR_H 1

#include <cstddef>
#include <new>
#include <bits/functexcept.h>
#include <tr1/array>
#include <bits/stl_move.h>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

 using std::size_t;
 using std::ptrdiff_t;

  /// Base class.
 template<typename _Tp>
    class array_allocator_base
    {
    public:
      typedef size_t     	size_type;
      typedef ptrdiff_t  	difference_type;
      typedef _Tp*       	pointer;
      typedef const _Tp* 	const_pointer;
      typedef _Tp&       	reference;
      typedef const _Tp&	const_reference;
      typedef _Tp        	value_type;

      pointer
      address(reference __x) const { return &__x; }

      const_pointer
      address(const_reference __x) const { return &__x; }

      void
      deallocate(pointer, size_type)
      { 
	// Does nothing.
      }

      size_type
      max_size() const throw() 
      { return size_t(-1) / sizeof(_Tp); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 402. wrong new expression in [some_] allocator::construct
      void 
      construct(pointer __p, const _Tp& __val) 
      { ::new((void *)__p) value_type(__val); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      template<typename... _Args>
        void
        construct(pointer __p, _Args&&... __args)
	{ ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); }
#endif

      void 
      destroy(pointer __p) { __p->~_Tp(); }
    };  

  /**
   *  @brief  An allocator that uses previously allocated memory.
   *  This memory can be externally, globally, or otherwise allocated.
   */
  template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> >
    class array_allocator : public array_allocator_base<_Tp>
    {
    public:
      typedef size_t     	size_type;
      typedef ptrdiff_t  	difference_type;
      typedef _Tp*       	pointer;
      typedef const _Tp* 	const_pointer;
      typedef _Tp&       	reference;
      typedef const _Tp& 	const_reference;
      typedef _Tp        	value_type;
      typedef _Array		array_type;

    private:
      array_type* 	_M_array;
      size_type 	_M_used;

    public:
     template<typename _Tp1, typename _Array1 = _Array>
        struct rebind
        { typedef array_allocator<_Tp1, _Array1> other; };

      array_allocator(array_type* __array = NULL) throw() 
      : _M_array(__array), _M_used(size_type()) { }

      array_allocator(const array_allocator& __o)  throw() 
      : _M_array(__o._M_array), _M_used(__o._M_used) { }

      template<typename _Tp1, typename _Array1>
        array_allocator(const array_allocator<_Tp1, _Array1>&) throw()
	: _M_array(NULL), _M_used(size_type()) { }

      ~array_allocator() throw() { }

      pointer
      allocate(size_type __n, const void* = 0)
      {
	if (_M_array == 0 || _M_used + __n > _M_array->size())
	  std::__throw_bad_alloc();
	pointer __ret = _M_array->begin() + _M_used;
	_M_used += __n;
	return __ret;
      }
    };

  template<typename _Tp, typename _Array>
    inline bool
    operator==(const array_allocator<_Tp, _Array>&,
	       const array_allocator<_Tp, _Array>&)
    { return true; }
  
  template<typename _Tp, typename _Array>
    inline bool
    operator!=(const array_allocator<_Tp, _Array>&, 
	       const array_allocator<_Tp, _Array>&)
    { return false; }

_GLIBCXX_END_NAMESPACE

#endif
// HP/SGI iterator extensions -*- C++ -*-

// Copyright (C) 2001, 2002, 2004, 2005 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * 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.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996-1998
 * 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 ext/iterator
 *  This file is a GNU extension to the Standard C++ Library (possibly
 *  containing extensions from the HP/SGI STL subset).
 */

#ifndef _EXT_ITERATOR
#define _EXT_ITERATOR 1

#pragma GCC system_header

#include <bits/concept_check.h>
#include <iterator>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  // There are two signatures for distance.  In addition to the one
  // taking two iterators and returning a result, there is another
  // taking two iterators and a reference-to-result variable, and
  // returning nothing.  The latter seems to be an SGI extension.
  // -- pedwards
  template<typename _InputIterator, typename _Distance>
    inline void
    __distance(_InputIterator __first, _InputIterator __last,
	       _Distance& __n, std::input_iterator_tag)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      while (__first != __last)
	{
	  ++__first;
	  ++__n;
	}
    }

  template<typename _RandomAccessIterator, typename _Distance>
    inline void
    __distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
	       _Distance& __n, std::random_access_iterator_tag)
    {
      // concept requirements
      __glibcxx_function_requires(_RandomAccessIteratorConcept<
				  _RandomAccessIterator>)
      __n += __last - __first;
    }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _InputIterator, typename _Distance>
    inline void
    distance(_InputIterator __first, _InputIterator __last,
             _Distance& __n)
    {
      // concept requirements -- taken care of in __distance
      __distance(__first, __last, __n, std::__iterator_category(__first));
    }

_GLIBCXX_END_NAMESPACE

#endif

// -*- C++ -*-

// Copyright (C) 2007 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.

// As a special exception, you may use this file as part of a free
// software library without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to
// produce an executable, this file does not by itself cause the
// resulting executable to be covered by the GNU General Public
// License.  This exception does not however invalidate any other
// reasons why the executable file might be covered by the GNU General
// Public License.

/** @file ext/numeric_traits.h
 *  This file is a GNU extension to the Standard C++ Library.
 */

#ifndef _EXT_NUMERIC_TRAITS
#define _EXT_NUMERIC_TRAITS 1

#pragma GCC system_header

#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  // Compile time constants for builtin types.
  // Sadly std::numeric_limits member functions cannot be used for this.
#define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0)
#define __glibcxx_digits(_Tp) \
  (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp))

#define __glibcxx_min(_Tp) \
  (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0)

#define __glibcxx_max(_Tp) \
  (__glibcxx_signed(_Tp) ? \
   (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0)

  template<typename _Value>
    struct __numeric_traits_integer
    {
      // Only integers for initialization of member constant.
      static const _Value __min = __glibcxx_min(_Value);
      static const _Value __max = __glibcxx_max(_Value);

      // NB: these two also available in std::numeric_limits as compile
      // time constants, but <limits> is big and we avoid including it.
      static const bool __is_signed = __glibcxx_signed(_Value);
      static const int __digits = __glibcxx_digits(_Value);      
    };

  template<typename _Value>
    const _Value __numeric_traits_integer<_Value>::__min;

  template<typename _Value>
    const _Value __numeric_traits_integer<_Value>::__max;

  template<typename _Value>
    const bool __numeric_traits_integer<_Value>::__is_signed;

  template<typename _Value>
    const int __numeric_traits_integer<_Value>::__digits;

#undef __glibcxx_signed
#undef __glibcxx_digits
#undef __glibcxx_min
#undef __glibcxx_max

#define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \
  (std::__are_same<_Tp, float>::__value ? _Fval \
   : std::__are_same<_Tp, double>::__value ? _Dval : _LDval)

#define __glibcxx_max_digits10(_Tp) \
  (2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \
			  __LDBL_MANT_DIG__) * 3010 / 10000)

#define __glibcxx_digits10(_Tp) \
  __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)

#define __glibcxx_max_exponent10(_Tp) \
  __glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \
		     __LDBL_MAX_10_EXP__)

  template<typename _Value>
    struct __numeric_traits_floating
    {
      // Only floating point types. See N1822. 
      static const int __max_digits10 = __glibcxx_max_digits10(_Value);

      // See above comment...
      static const bool __is_signed = true;
      static const int __digits10 = __glibcxx_digits10(_Value);
      static const int __max_exponent10 = __glibcxx_max_exponent10(_Value);
    };

  template<typename _Value>
    const int __numeric_traits_floating<_Value>::__max_digits10;

  template<typename _Value>
    const bool __numeric_traits_floating<_Value>::__is_signed;

  template<typename _Value>
    const int __numeric_traits_floating<_Value>::__digits10;

  template<typename _Value>
    const int __numeric_traits_floating<_Value>::__max_exponent10;

  template<typename _Value>
    struct __numeric_traits
    : public __conditional_type<std::__is_integer<_Value>::__value,
				__numeric_traits_integer<_Value>,
				__numeric_traits_floating<_Value> >::__type
    { };

_GLIBCXX_END_NAMESPACE

#undef __glibcxx_floating
#undef __glibcxx_max_digits10
#undef __glibcxx_digits10
#undef __glibcxx_max_exponent10

#endif 
// Numeric extensions -*- C++ -*-

// Copyright (C) 2002, 2004, 2005 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * 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.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996
 * 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 ext/numeric
 *  This file is a GNU extension to the Standard C++ Library (possibly
 *  containing extensions from the HP/SGI STL subset). 
 */

#ifndef _EXT_NUMERIC
#define _EXT_NUMERIC 1

#pragma GCC system_header

#include <bits/concept_check.h>
#include <numeric>

#include <ext/functional> // For identity_element

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  // Returns __x ** __n, where __n >= 0.  _Note that "multiplication"
  // is required to be associative, but not necessarily commutative.
  template<typename _Tp, typename _Integer, typename _MonoidOperation>
    _Tp
    __power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
    {
      if (__n == 0)
	return identity_element(__monoid_op);
      else
	{
	  while ((__n & 1) == 0)
	    {
	      __n >>= 1;
	      __x = __monoid_op(__x, __x);
	    }

	  _Tp __result = __x;
	  __n >>= 1;
	  while (__n != 0)
	    {
	      __x = __monoid_op(__x, __x);
	      if ((__n & 1) != 0)
		__result = __monoid_op(__result, __x);
	      __n >>= 1;
	    }
	  return __result;
	}
    }

  template<typename _Tp, typename _Integer>
    inline _Tp
    __power(_Tp __x, _Integer __n)
    { return __power(__x, __n, std::multiplies<_Tp>()); }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  // Alias for the internal name __power.  Note that power is an extension,
  // not part of the C++ standard.
  template<typename _Tp, typename _Integer, typename _MonoidOperation>
    inline _Tp
    power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
    { return __power(__x, __n, __monoid_op); }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  template<typename _Tp, typename _Integer>
    inline _Tp
    power(_Tp __x, _Integer __n)
    { return __power(__x, __n); }

  /**
   *  This is an SGI extension.
   *  @ingroup SGIextensions
   *  @doctodo
  */
  // iota is not part of the C++ standard.  It is an extension.
  template<typename _ForwardIter, typename _Tp>
    void
    iota(_ForwardIter __first, _ForwardIter __last, _Tp __value)
    {
      // concept requirements
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<_ForwardIter>)
      __glibcxx_function_requires(_ConvertibleConcept<_Tp,
	    typename std::iterator_traits<_ForwardIter>::value_type>)

      while (__first != __last)
	*__first++ = __value++;
    }

_GLIBCXX_END_NAMESPACE

#endif

// Versatile string -*- C++ -*-

// Copyright (C) 2005, 2006, 2007 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/** @file ext/vstring.h
 *  This file is a GNU extension to the Standard C++ Library.
 */

#ifndef _VSTRING_H
#define _VSTRING_H 1

#pragma GCC system_header

#include <ext/vstring_util.h>
#include <ext/rc_string_base.h>
#include <ext/sso_string_base.h>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  /**
   *  @class __versa_string vstring.h
   *  @brief  Managing sequences of characters and character-like objects.
   */

  // Template class __versa_string
  template<typename _CharT, typename _Traits, typename _Alloc,
	   template <typename, typename, typename> class _Base>
    class __versa_string
    : private _Base<_CharT, _Traits, _Alloc>
    {
      typedef _Base<_CharT, _Traits, _Alloc>                __vstring_base;      
      typedef typename __vstring_base::_CharT_alloc_type    _CharT_alloc_type;

      // Types:
    public:
      typedef _Traits					    traits_type;
      typedef typename _Traits::char_type		    value_type;
      typedef _Alloc					    allocator_type;
      typedef typename _CharT_alloc_type::size_type	    size_type;
      typedef typename _CharT_alloc_type::difference_type   difference_type;
      typedef typename _CharT_alloc_type::reference	    reference;
      typedef typename _CharT_alloc_type::const_reference   const_reference;
      typedef typename _CharT_alloc_type::pointer	    pointer;
      typedef typename _CharT_alloc_type::const_pointer	    const_pointer;
      typedef __gnu_cxx::__normal_iterator<pointer, __versa_string>  iterator;
      typedef __gnu_cxx::__normal_iterator<const_pointer, __versa_string>
                                                            const_iterator;
      typedef std::reverse_iterator<const_iterator>	const_reverse_iterator;
      typedef std::reverse_iterator<iterator>		    reverse_iterator;

      // Data Member (public):
      ///  Value returned by various member functions when they fail.
      static const size_type	npos = static_cast<size_type>(-1);

    private:
      size_type
      _M_check(size_type __pos, const char* __s) const
      {
	if (__pos > this->size())
	  std::__throw_out_of_range(__N(__s));
	return __pos;
      }

      void
      _M_check_length(size_type __n1, size_type __n2, const char* __s) const
      {
	if (this->max_size() - (this->size() - __n1) < __n2)
	  std::__throw_length_error(__N(__s));
      }

      // NB: _M_limit doesn't check for a bad __pos value.
      size_type
      _M_limit(size_type __pos, size_type __off) const
      {
	const bool __testoff =  __off < this->size() - __pos;
	return __testoff ? __off : this->size() - __pos;
      }

      // True if _Rep and source do not overlap.
      bool
      _M_disjunct(const _CharT* __s) const
      {
	return (std::less<const _CharT*>()(__s, this->_M_data())
		|| std::less<const _CharT*>()(this->_M_data()
					      + this->size(), __s));
      }

      // For the internal use we have functions similar to `begin'/`end'
      // but they do not call _M_leak.
      iterator
      _M_ibegin() const
      { return iterator(this->_M_data()); }

      iterator
      _M_iend() const
      { return iterator(this->_M_data() + this->_M_length()); }

    public:
      // Construct/copy/destroy:
      // NB: We overload ctors in some cases instead of using default
      // arguments, per 17.4.4.4 para. 2 item 2.

      /**
       *  @brief  Default constructor creates an empty string.
       */
      __versa_string()
      : __vstring_base() { }
      
      /**
       *  @brief  Construct an empty string using allocator @a a.
       */
      explicit
      __versa_string(const _Alloc& __a)
      : __vstring_base(__a) { }

      // NB: per LWG issue 42, semantics different from IS:
      /**
       *  @brief  Construct string with copy of value of @a str.
       *  @param  str  Source string.
       */
      __versa_string(const __versa_string& __str)
      : __vstring_base(__str) { }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      /**
       *  @brief  String move constructor.
       *  @param  str  Source string.
       *
       *  The newly-constructed %string contains the exact contents of @a str.
       *  The contents of @a str are a valid, but unspecified string.
       */
      __versa_string(__versa_string&& __str)
      : __vstring_base(std::forward<__vstring_base>(__str)) { }
#endif

      /**
       *  @brief  Construct string as copy of a substring.
       *  @param  str  Source string.
       *  @param  pos  Index of first character to copy from.
       *  @param  n  Number of characters to copy (default remainder).
       */
      __versa_string(const __versa_string& __str, size_type __pos,
		     size_type __n = npos)
      : __vstring_base(__str._M_data()
		       + __str._M_check(__pos,
					"__versa_string::__versa_string"),
		       __str._M_data() + __str._M_limit(__pos, __n)
		       + __pos, _Alloc()) { }

      /**
       *  @brief  Construct string as copy of a substring.
       *  @param  str  Source string.
       *  @param  pos  Index of first character to copy from.
       *  @param  n  Number of characters to copy.
       *  @param  a  Allocator to use.
       */
      __versa_string(const __versa_string& __str, size_type __pos,
		     size_type __n, const _Alloc& __a)
      : __vstring_base(__str._M_data()
		       + __str._M_check(__pos,
					"__versa_string::__versa_string"),
		       __str._M_data() + __str._M_limit(__pos, __n)
		       + __pos, __a) { }

      /**
       *  @brief  Construct string initialized by a character array.
       *  @param  s  Source character array.
       *  @param  n  Number of characters to copy.
       *  @param  a  Allocator to use (default is default allocator).
       *
       *  NB: @a s must have at least @a n characters, '\0' has no special
       *  meaning.
       */
      __versa_string(const _CharT* __s, size_type __n,
		     const _Alloc& __a = _Alloc())
      : __vstring_base(__s, __s + __n, __a) { }

      /**
       *  @brief  Construct string as copy of a C string.
       *  @param  s  Source C string.
       *  @param  a  Allocator to use (default is default allocator).
       */
      __versa_string(const _CharT* __s, const _Alloc& __a = _Alloc())
      : __vstring_base(__s, __s ? __s + traits_type::length(__s) :
		       __s + npos, __a) { }

      /**
       *  @brief  Construct string as multiple characters.
       *  @param  n  Number of characters.
       *  @param  c  Character to use.
       *  @param  a  Allocator to use (default is default allocator).
       */
      __versa_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc())
      : __vstring_base(__n, __c, __a) { }

      /**
       *  @brief  Construct string as copy of a range.
       *  @param  beg  Start of range.
       *  @param  end  End of range.
       *  @param  a  Allocator to use (default is default allocator).
       */
      template<class _InputIterator>
        __versa_string(_InputIterator __beg, _InputIterator __end,
		       const _Alloc& __a = _Alloc())
	: __vstring_base(__beg, __end, __a) { }

      /**
       *  @brief  Destroy the string instance.
       */
      ~__versa_string() { }	

      /**
       *  @brief  Assign the value of @a str to this string.
       *  @param  str  Source string.
       */
      __versa_string&
      operator=(const __versa_string& __str) 
      { return this->assign(__str); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      /**
       *  @brief  String move assignment operator.
       *  @param  str  Source string.
       *
       *  The contents of @a str are moved into this string (without copying).
       *  @a str is a valid, but unspecified string.
       */
      __versa_string&
      operator=(__versa_string&& __str)
      {
	if (this != &__str)
	  this->swap(__str);
	return *this;
      }
#endif

      /**
       *  @brief  Copy contents of @a s into this string.
       *  @param  s  Source null-terminated string.
       */
      __versa_string&
      operator=(const _CharT* __s) 
      { return this->assign(__s); }

      /**
       *  @brief  Set value to string of length 1.
       *  @param  c  Source character.
       *
       *  Assigning to a character makes this string length 1 and
       *  (*this)[0] == @a c.
       */
      __versa_string&
      operator=(_CharT __c) 
      { 
	this->assign(1, __c); 
	return *this;
      }

      // Iterators:
      /**
       *  Returns a read/write iterator that points to the first character in
       *  the %string.  Unshares the string.
       */
      iterator
      begin()
      {
	this->_M_leak();
	return iterator(this->_M_data());
      }

      /**
       *  Returns a read-only (constant) iterator that points to the first
       *  character in the %string.
       */
      const_iterator
      begin() const
      { return const_iterator(this->_M_data()); }

      /**
       *  Returns a read/write iterator that points one past the last
       *  character in the %string.  Unshares the string.
       */
      iterator
      end()
      {
	this->_M_leak();
	return iterator(this->_M_data() + this->size());
      }

      /**
       *  Returns a read-only (constant) iterator that points one past the
       *  last character in the %string.
       */
      const_iterator
      end() const
      { return const_iterator(this->_M_data() + this->size()); }

      /**
       *  Returns a read/write reverse iterator that points to the last
       *  character in the %string.  Iteration is done in reverse element
       *  order.  Unshares the string.
       */
      reverse_iterator
      rbegin()
      { return reverse_iterator(this->end()); }

      /**
       *  Returns a read-only (constant) reverse iterator that points
       *  to the last character in the %string.  Iteration is done in
       *  reverse element order.
       */
      const_reverse_iterator
      rbegin() const
      { return const_reverse_iterator(this->end()); }

      /**
       *  Returns a read/write reverse iterator that points to one before the
       *  first character in the %string.  Iteration is done in reverse
       *  element order.  Unshares the string.
       */
      reverse_iterator
      rend()
      { return reverse_iterator(this->begin()); }

      /**
       *  Returns a read-only (constant) reverse iterator that points
       *  to one before the first character in the %string.  Iteration
       *  is done in reverse element order.
       */
      const_reverse_iterator
      rend() const
      { return const_reverse_iterator(this->begin()); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      /**
       *  Returns a read-only (constant) iterator that points to the first
       *  character in the %string.
       */
      const_iterator
      cbegin() const
      { return const_iterator(this->_M_data()); }

      /**
       *  Returns a read-only (constant) iterator that points one past th31415161718191:1;1<1=1>1?1@1A1B1C1D1E1F1G1H1I1J1K1L1M1N1O1P1Q1R1S1T1U1V1W1X1Y1Z1[1\1]1^1_1`1a1b1c1d1e1f1g1h1i1j1k1l1m1n1o1p1q1r1s1t1u1v1w1x1y1z1{1|1}1e
       *  last character in the %string.
       */
      const_iterator
      cend() const
      { return const_iterator(this->_M_data() + this->size()); }

      /**
       *  Returns a read-only (constant) reverse iterator that points
       *  to the last character in the %string.  Iteration is done in
       *  reverse element order.
       */
      const_reverse_iterator
      crbegin() const
      { return const_reverse_iterator(this->end()); }

      /**
       *  Returns a read-only (constant) reverse iterator that points
       *  to one before the first character in the %string.  Iteration
       *  is done in reverse element order.
       */
      const_reverse_iterator
      crend() const
      { return const_reverse_iterator(this->begin()); }
#endif

    public:
      // Capacity:
      ///  Returns the number of characters in the string, not including any
      ///  null-termination.
      size_type
      size() const
      { return this->_M_length(); }

      ///  Returns the number of characters in the string, not including any
      ///  null-termination.
      size_type
      length() const
      { return this->_M_length(); }

      /// Returns the size() of the largest possible %string.
      size_type
      max_size() const
      { return this->_M_max_size(); }

      /**
       *  @brief  Resizes the %string to the specified number of characters.
       *  @param  n  Number of characters the %string should contain.
       *  @param  c  Character to fill any new elements.
       *
       *  This function will %resize the %string to the specified
       *  number of characters.  If the number is smaller than the
       *  %string's current size the %string is truncated, otherwise
       *  the %string is extended and new elements are set to @a c.
       */
      void
      resize(size_type __n, _CharT __c);

      /**
       *  @brief  Resizes the %string to the specified number of characters.
       *  @param  n  Number of characters the %string should contain.
       *
       *  This function will resize the %string to the specified length.  If
       *  the new size is smaller than the %string's current size the %string
       *  is truncated, otherwise the %string is extended and new characters
       *  are default-constructed.  For basic types such as char, this means
       *  setting them to 0.
       */
      void
      resize(size_type __n)
      { this->resize(__n, _CharT()); }

      /**
       *  Returns the total number of characters that the %string can hold
       *  before needing to allocate more memory.
       */
      size_type
      capacity() const
      { return this->_M_capacity(); }

      /**
       *  @brief  Attempt to preallocate enough memory for specified number of
       *          characters.
       *  @param  res_arg  Number of characters required.
       *  @throw  std::length_error  If @a res_arg exceeds @c max_size().
       *
       *  This function attempts to reserve enough memory for the
       *  %string to hold the specified number of characters.  If the
       *  number requested is more than max_size(), length_error is
       *  thrown.
       *
       *  The advantage of this function is that if optimal code is a
       *  necessity and the user can determine the string length that will be
       *  required, the user can reserve the memory in %advance, and thus
       *  prevent a possible reallocation of memory and copying of %string
       *  data.
       */
      void
      reserve(size_type __res_arg = 0)
      { this->_M_reserve(__res_arg); }

      /**
       *  Erases the string, making it empty.
       */
      void
      clear()
      { this->_M_clear(); }

      /**
       *  Returns true if the %string is empty.  Equivalent to *this == "".
       */
      bool
      empty() const
      { return this->size() == 0; }

      // Element access:
      /**
       *  @brief  Subscript access to the data contained in the %string.
       *  @param  pos  The index of the character to access.
       *  @return  Read-only (constant) reference to the character.
       *
       *  This operator allows for easy, array-style, data access.
       *  Note that data access with this operator is unchecked and
       *  out_of_range lookups are not defined. (For checked lookups
       *  see at().)
       */
      const_reference
      operator[] (size_type __pos) const
      {
	_GLIBCXX_DEBUG_ASSERT(__pos <= this->size());
	return this->_M_data()[__pos];
      }

      /**
       *  @brief  Subscript access to the data contained in the %string.
       *  @param  pos  The index of the character to access.
       *  @return  Read/write reference to the character.
       *
       *  This operator allows for easy, array-style, data access.
       *  Note that data access with this operator is unchecked and
       *  out_of_range lookups are not defined. (For checked lookups
       *  see at().)  Unshares the string.
       */
      reference
      operator[](size_type __pos)
      {
        // allow pos == size() as v3 extension:
	_GLIBCXX_DEBUG_ASSERT(__pos <= this->size());
        // but be strict in pedantic mode:
	_GLIBCXX_DEBUG_PEDASSERT(__pos < this->size());
	this->_M_leak();
	return this->_M_data()[__pos];
      }

      /**
       *  @brief  Provides access to the data contained in the %string.
       *  @param n The index of the character to access.
       *  @return  Read-only (const) reference to the character.
       *  @throw  std::out_of_range  If @a n is an invalid index.
       *
       *  This function provides for safer data access.  The parameter is
       *  first checked that it is in the range of the string.  The function
       *  throws out_of_range if the check fails.
       */
      const_reference
      at(size_type __n) const
      {
	if (__n >= this->size())
	  std::__throw_out_of_range(__N("__versa_string::at"));
	return this->_M_data()[__n];
      }

      /**
       *  @brief  Provides access to the data contained in the %string.
       *  @param n The index of the character to access.
       *  @return  Read/write reference to the character.
       *  @throw  std::out_of_range  If @a n is an invalid index.
       *
       *  This function provides for safer data access.  The parameter is
       *  first checked that it is in the range of the string.  The function
       *  throws out_of_range if the check fails.  Success results in
       *  unsharing the string.
       */
      reference
      at(size_type __n)
      {
	if (__n >= this->size())
	  std::__throw_out_of_range(__N("__versa_string::at"));
	this->_M_leak();
	return this->_M_data()[__n];
      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      /**
       *  Returns a read/write reference to the data at the first
       *  element of the %string.
       */
      reference
      front()
      { return *begin(); }

      /**
       *  Returns a read-only (constant) reference to the data at the first
       *  element of the %string.
       */
      const_reference
      front() const
      { return *begin(); }

      /**
       *  Returns a read/write reference to the data at the last
       *  element of the %string.
       */
      reference
      back()
      { return *(end() - 1); }

      /**
       *  Returns a read-only (constant) reference to the data at the
       *  last element of the %string.
       */
      const_reference
      back() const
      { return *(end() - 1); }
#endif

      // Modifiers:
      /**
       *  @brief  Append a string to this string.
       *  @param str  The string to append.
       *  @return  Reference to this string.
       */
      __versa_string&
      operator+=(const __versa_string& __str)
      { return this->append(__str); }

      /**
       *  @brief  Append a C string.
       *  @param s  The C string to append.
       *  @return  Reference to this string.
       */
      __versa_string&
      operator+=(const _CharT* __s)
      { return this->append(__s); }

      /**
       *  @brief  Append a character.
       *  @param c  The character to append.
       *  @return  Reference to this string.
       */
      __versa_string&
      operator+=(_CharT __c)
      { 
	this->push_back(__c);
	return *this;
      }

      /**
       *  @brief  Append a string to this string.
       *  @param str  The string to append.
       *  @return  Reference to this string.
       */
      __versa_string&
      append(const __versa_string& __str)
      { return _M_append(__str._M_data(), __str.size()); }

      /**
       *  @brief  Append a substring.
       *  @param str  The string to append.
       *  @param pos  Index of the first character of str to append.
       *  @param n  The number of characters to append.
       *  @return  Reference to this string.
       *  @throw  std::out_of_range if @a pos is not a valid index.
       *
       *  This function appends @a n characters from @a str starting at @a pos
       *  to this string.  If @a n is is larger than the number of available
       *  characters in @a str, the remainder of @a str is appended.
       */
      __versa_string&
      append(const __versa_string& __str, size_type __pos, size_type __n)
      { return _M_append(__str._M_data()
			 + __str._M_check(__pos, "__versa_string::append"),
			 __str._M_limit(__pos, __n)); }

      /**
       *  @brief  Append a C substring.
       *  @param s  The C string to append.
       *  @param n  The number of characters to append.
       *  @return  Reference to this string.
       */
      __versa_string&
      append(const _CharT* __s, size_type __n)
      {
	__glibcxx_requires_string_len(__s, __n);
	_M_check_length(size_type(0), __n, "__versa_string::append");
	return _M_append(__s, __n);
      }

      /**
       *  @brief  Append a C string.
       *  @param s  The C string to append.
       *  @return  Reference to this string.
       */
      __versa_string&
      append(const _CharT* __s)
      {
	__glibcxx_requires_string(__s);
	const size_type __n = traits_type::length(__s);
	_M_check_length(size_type(0), __n, "__versa_string::append");
	return _M_append(__s, __n);
      }

      /**
       *  @brief  Append multiple characters.
       *  @param n  The number of characters to append.
       *  @param c  The character to use.
       *  @return  Reference to this string.
       *
       *  Appends n copies of c to this string.
       */
      __versa_string&
      append(size_type __n, _CharT __c)
      { return _M_replace_aux(this->size(), size_type(0), __n, __c); }

      /**
       *  @brief  Append a range of characters.
       *  @param first  Iterator referencing the first character to append.
       *  @param last  Iterator marking the end of the range.
       *  @return  Reference to this string.
       *
       *  Appends characters in the range [first,last) to this string.
       */
      template<class _InputIterator>
        __versa_string&
        append(_InputIterator __first, _InputIterator __last)
        { return this->replace(_M_iend(), _M_iend(), __first, __last); }

      /**
       *  @brief  Append a single character.
       *  @param c  Character to append.
       */
      void
      push_back(_CharT __c)
      { 
	const size_type __size = this->size();
	if (__size + 1 > this->capacity() || this->_M_is_shared())
	  this->_M_mutate(__size, size_type(0), 0, size_type(1));
	traits_type::assign(this->_M_data()[__size], __c);
	this->_M_set_length(__size + 1);
      }

      /**
       *  @brief  Set value to contents of another string.
       *  @param  str  Source string to use.
       *  @return  Reference to this string.
       */
      __versa_string&
      assign(const __versa_string& __str)
      {
	this->_M_assign(__str);
	return *this;
      }

      /**
       *  @brief  Set value to a substring of a string.
       *  @param str  The string to use.
       *  @param pos  Index of the first character of str.
       *  @param n  Number of characters to use.
       *  @return  Reference to this string.
       *  @throw  std::out_of_range if @a pos is not a valid index.
       *
       *  This function sets this string to the substring of @a str consisting
       *  of @a n characters at @a pos.  If @a n is is larger than the number
       *  of available characters in @a str, the remainder of @a str is used.
       */
      __versa_string&
      assign(const __versa_string& __str, size_type __pos, size_type __n)
      { return _M_replace(size_type(0), this->size(), __str._M_data()
			  + __str._M_check(__pos, "__versa_string::assign"),
			  __str._M_limit(__pos, __n)); }

      /**
       *  @brief  Set value to a C substring.
       *  @param s  The C string to use.
       *  @param n  Number of characters to use.
       *  @return  Reference to this string.
       *
       *  This function sets the value of this string to the first @a n
       *  characters of @a s.  If @a n is is larger than the number of
       *  available characters in @a s, the remainder of @a s is used.
       */
      __versa_string&
      assign(const _CharT* __s, size_type __n)
      {
	__glibcxx_requires_string_len(__s, __n);
	return _M_replace(size_type(0), this->size(), __s, __n);
      }

      /**
       *  @brief  Set value to contents of a C string.
       *  @par