herefore we resort to template
  // template to "flatten" loosened return value types.
  // At some point we use partial specialization to remove one level
  // template nesting due to _Expr<>
  //

  // This class is NOT defined. It doesn't need to.
  template<typename _Tp1, typename _Tp2> class _Constant;

  // Implementations of unary functions applied to valarray<>s.
  // I use hard-coded object functions here instead of a generic
  // approach like pointers to function:
  //    1) correctness: some functions take references, others values.
  //       we can't deduce the correct type afterwards.
  //    2) efficiency -- object functions can be easily inlined
  //    3) be Koenig-lookup-friendly

  struct __abs
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return abs(__t); }
  };

  struct __cos
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return cos(__t); }
  };

  struct __acos
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return acos(__t); }
  };

  struct __cosh
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return cosh(__t); }
  };

  struct __sin
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return sin(__t); }
  };

  struct __asin
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return asin(__t); }
  };

  struct __sinh
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return sinh(__t); }
  };

  struct __tan
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return tan(__t); }
  };

  struct __atan
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return atan(__t); }
  };

  struct __tanh
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return tanh(__t); }
  };

  struct __exp
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return exp(__t); }
  };

  struct __log
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return log(__t); }
  };

  struct __log10
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return log10(__t); }
  };

  struct __sqrt
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return sqrt(__t); }
  };

  // In the past, we used to tailor operator applications semantics
  // to the specialization of standard function objects (i.e. plus<>, etc.)
  // That is incorrect.  Therefore we provide our own surrogates.

  struct __unary_plus
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return +__t; }
  };

  struct __negate
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return -__t; }
  };

  struct __bitwise_not
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __t) const
      { return ~__t; }
  };

  struct __plus
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x + __y; }
  };

  struct __minus
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x - __y; }
  };

  struct __multiplies
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x * __y; }
  };

  struct __divides
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x / __y; }
  };

  struct __modulus
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x % __y; }
  };

  struct __bitwise_xor
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x ^ __y; }
  };

  struct __bitwise_and
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x & __y; }
  };

  struct __bitwise_or
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x | __y; }
  };

  struct __shift_left
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x << __y; }
  };

  struct __shift_right
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return __x >> __y; }
  };

  struct __logical_and
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x && __y; }
  };

  struct __logical_or
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x || __y; }
  };

  struct __logical_not
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x) const { return !__x; }
  };

  struct __equal_to
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x == __y; }
  };

  struct __not_equal_to
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x != __y; }
  };

  struct __less
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x < __y; }
  };

  struct __greater
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x > __y; }
  };

  struct __less_equal
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x <= __y; }
  };

  struct __greater_equal
  {
    template<typename _Tp>
      bool operator()(const _Tp& __x, const _Tp& __y) const
      { return __x >= __y; }
  };

  // The few binary functions we miss.
  struct __atan2
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return atan2(__x, __y); }
  };

  struct __pow
  {
    template<typename _Tp>
      _Tp operator()(const _Tp& __x, const _Tp& __y) const
      { return pow(__x, __y); }
  };


  // We need these bits in order to recover the return type of
  // some functions/operators now that we're no longer using
  // function templates.
  template<typename, typename _Tp>
    struct __fun
    {
      typedef _Tp result_type;
    };

  // several specializations for relational operators.
  template<typename _Tp>
    struct __fun<__logical_not, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__logical_and, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__logical_or, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__less, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__greater, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__less_equal, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__greater_equal, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__equal_to, _Tp>
    {
      typedef bool result_type;
    };

  template<typename _Tp>
    struct __fun<__not_equal_to, _Tp>
    {
      typedef bool result_type;
    };

  //
  // Apply function taking a value/const reference closure
  //

  template<typename _Dom, typename _Arg>
    class _FunBase
    {
    public:
      typedef typename _Dom::value_type value_type;

      _FunBase(const _Dom& __e, value_type __f(_Arg))
      : _M_expr(__e), _M_func(__f) {}

      value_type operator[](size_t __i) const
      { return _M_func (_M_expr[__i]); }

      size_t size() const { return _M_expr.size ();}

    private:
      const _Dom& _M_expr;
      value_type (*_M_func)(_Arg);
    };

  template<class _Dom>
    struct _ValFunClos<_Expr,_Dom> : _FunBase<_Dom, typename _Dom::value_type>
    {
      typedef _FunBase<_Dom, typename _Dom::value_type> _Base;
      typedef typename _Base::value_type value_type;
      typedef value_type _Tp;

      _ValFunClos(const _Dom& __e, _Tp __f(_Tp)) : _Base(__e, __f) {}
    };

  template<typename _Tp>
    struct _ValFunClos<_ValArray,_Tp> : _FunBase<valarray<_Tp>, _Tp>
    {
      typedef _FunBase<valarray<_Tp>, _Tp> _Base;
      typedef _Tp value_type;

      _ValFunClos(const valarray<_Tp>& __v, _Tp __f(_Tp)) : _Base(__v, __f) {}
    };

  template<class _Dom>
    struct _RefFunClos<_Expr, _Dom>
    : _FunBase<_Dom, const typename _Dom::value_type&>
    {
      typedef _FunBase<_Dom, const typename _Dom::value_type&> _Base;
      typedef typename _Base::value_type value_type;
      typedef value_type _Tp;

      _RefFunClos(const _Dom& __e, _Tp __f(const _Tp&))
      : _Base(__e, __f) {}
    };

  template<typename _Tp>
    struct _RefFunClos<_ValArray, _Tp>
    : _FunBase<valarray<_Tp>, const _Tp&>
    {
      typedef _FunBase<valarray<_Tp>, const _Tp&> _Base;
      typedef _Tp value_type;

      _RefFunClos(const valarray<_Tp>& __v, _Tp __f(const _Tp&))
      : _Base(__v, __f) {}
    };

  //
  // Unary expression closure.
  //

  template<class _Oper, class _Arg>
    class _UnBase
    {
    public:
      typedef typename _Arg::value_type _Vt;
      typedef typename __fun<_Oper, _Vt>::result_type value_type;

      _UnBase(const _Arg& __e) : _M_expr(__e) {}

      value_type operator[](size_t __i) const
      { return _Oper()(_M_expr[__i]); }

      size_t size() const { return _M_expr.size(); }
      
    private:
      const _Arg& _M_expr;
    };

  template<class _Oper, class _Dom>
    struct _UnClos<_Oper, _Expr, _Dom>
    : _UnBase<_Oper, _Dom>
    {
      typedef _Dom _Arg;
      typedef _UnBase<_Oper, _Dom> _Base;
      typedef typename _Base::value_type value_type;

      _UnClos(const _Arg& __e) : _Base(__e) {}
    };

  template<class _Oper, typename _Tp>
    struct _UnClos<_Oper, _ValArray, _Tp>
    : _UnBase<_Oper, valarray<_Tp> >
    {
      typedef valarray<_Tp> _Arg;
      typedef _UnBase<_Oper, valarray<_Tp> > _Base;
      typedef typename _Base::value_type value_type;

      _UnClos(const _Arg& __e) : _Base(__e) {}
    };


  //
  // Binary expression((
((((( closure.
  //

  template<class _Oper, class _FirstArg, class _SecondArg>
    class _BinBase
    {
    public:
      typedef typename _FirstArg::value_type _Vt;
      typedef typename __fun<_Oper, _Vt>::result_type value_type;

      _BinBase(const _FirstArg& __e1, const _SecondArg& __e2)
      : _M_expr1(__e1), _M_expr2(__e2) {}

      value_type operator[](size_t __i) const
      { return _Oper()(_M_expr1[__i], _M_expr2[__i]); }

      size_t size() const { return _M_expr1.size(); }

    private:
      const _FirstArg& _M_expr1;
      const _SecondArg& _M_expr2;
    };


  template<class _Oper, class _Clos>
    class _BinBase2
    {
    public:
      typedef typename _Clos::value_type _Vt;
      typedef typename __fun<_Oper, _Vt>::result_type value_type;

      _BinBase2(const _Clos& __e, const _Vt& __t)
      : _M_expr1(__e), _M_expr2(__t) {}

      value_type operator[](size_t __i) const
      { return _Oper()(_M_expr1[__i], _M_expr2); }

      size_t size() const { return _M_expr1.size(); }

    private:
      const _Clos& _M_expr1;
      const _Vt& _M_expr2;
    };

  template<class _Oper, class _Clos>
    class _BinBase1
    {
    public:
      typedef typename _Clos::value_type _Vt;
      typedef typename __fun<_Oper, _Vt>::result_type value_type;

      _BinBase1(const _Vt& __t, const _Clos& __e)
      : _M_expr1(__t), _M_expr2(__e) {}

      value_type operator[](size_t __i) const
      { return _Oper()(_M_expr1, _M_expr2[__i]); }

      size_t size() const { return _M_expr2.size(); }

    private:
      const _Vt& _M_expr1;
      const _Clos& _M_expr2;
    };

  template<class _Oper, class _Dom1, class _Dom2>
    struct _BinClos<_Oper, _Expr, _Expr, _Dom1, _Dom2>
    : _BinBase<_Oper, _Dom1, _Dom2>
    {
      typedef _BinBase<_Oper, _Dom1, _Dom2> _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const _Dom1& __e1, const _Dom2& __e2) : _Base(__e1, __e2) {}
    };

  template<class _Oper, typename _Tp>
    struct _BinClos<_Oper,_ValArray, _ValArray, _Tp, _Tp>
    : _BinBase<_Oper, valarray<_Tp>, valarray<_Tp> >
    {
      typedef _BinBase<_Oper, valarray<_Tp>, valarray<_Tp> > _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const valarray<_Tp>& __v, const valarray<_Tp>& __w)
      : _Base(__v, __w) {}
    };

  template<class _Oper, class _Dom>
    struct _BinClos<_Oper, _Expr, _ValArray, _Dom, typename _Dom::value_type>
    : _BinBase<_Oper, _Dom, valarray<typename _Dom::value_type> >
    {
      typedef typename _Dom::value_type _Tp;
      typedef _BinBase<_Oper,_Dom,valarray<_Tp> > _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const _Dom& __e1, const valarray<_Tp>& __e2)
      : _Base(__e1, __e2) {}
    };

  template<class _Oper, class _Dom>
    struct _BinClos<_Oper, _ValArray, _Expr, typename _Dom::value_type, _Dom>
    : _BinBase<_Oper, valarray<typename _Dom::value_type>,_Dom>
    {
      typedef typename _Dom::value_type _Tp;
      typedef _BinBase<_Oper, valarray<_Tp>, _Dom> _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const valarray<_Tp>& __e1, const _Dom& __e2)
      : _Base(__e1, __e2) {}
    };

  template<class _Oper, class _Dom>
    struct _BinClos<_Oper, _Expr, _Constant, _Dom, typename _Dom::value_type>
    : _BinBase2<_Oper, _Dom>
    {
      typedef typename _Dom::value_type _Tp;
      typedef _BinBase2<_Oper,_Dom> _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const _Dom& __e1, const _Tp& __e2) : _Base(__e1, __e2) {}
    };

  template<class _Oper, class _Dom>
    struct _BinClos<_Oper, _Constant, _Expr, typename _Dom::value_type, _Dom>
    : _BinBase1<_Oper, _Dom>
    {
      typedef typename _Dom::value_type _Tp;
      typedef _BinBase1<_Oper, _Dom> _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const _Tp& __e1, const _Dom& __e2) : _Base(__e1, __e2) {}
    };

  template<class _Oper, typename _Tp>
    struct _BinClos<_Oper, _ValArray, _Constant, _Tp, _Tp>
    : _BinBase2<_Oper, valarray<_Tp> >
    {
      typedef _BinBase2<_Oper,valarray<_Tp> > _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const valarray<_Tp>& __v, const _Tp& __t) : _Base(__v, __t) {}
    };

  template<class _Oper, typename _Tp>
    struct _BinClos<_Oper, _Constant, _ValArray, _Tp, _Tp>
    : _BinBase1<_Oper, valarray<_Tp> >
    {
      typedef _BinBase1<_Oper, valarray<_Tp> > _Base;
      typedef typename _Base::value_type value_type;

      _BinClos(const _Tp& __t, const valarray<_Tp>& __v) : _Base(__t, __v) {}
    };

    //
    // slice_array closure.
    //
  template<typename _Dom> 
    class _SBase
    {
    public:
      typedef typename _Dom::value_type value_type;
      
      _SBase (const _Dom& __e, const slice& __s)
      : _M_expr (__e), _M_slice (__s) {}
        
      value_type
      operator[] (size_t __i) const
      { return _M_expr[_M_slice.start () + __i * _M_slice.stride ()]; }
        
      size_t
      size() const
      { return _M_slice.size (); }

    private:
      const _Dom& _M_expr;
      const slice& _M_slice;
    };

  template<typename _Tp>
    class _SBase<_Array<_Tp> >
    {
    public:
      typedef _Tp value_type;
      
      _SBase (_Array<_Tp> __a, const slice& __s)
      : _M_array (__a._M_data+__s.start()), _M_size (__s.size()),
	_M_stride (__s.stride()) {}
        
      value_type
      operator[] (size_t __i) const
      { return _M_array._M_data[__i * _M_stride]; }
      
      size_t
      size() const
      { return _M_size; }

    private:
      const _Array<_Tp> _M_array;
      const size_t _M_size;
      const size_t _M_stride;
    };

  template<class _Dom>
    struct _SClos<_Expr, _Dom>
    : _SBase<_Dom>
    {
      typedef _SBase<_Dom> _Base;
      typedef typename _Base::value_type value_type;
      
      _SClos (const _Dom& __e, const slice& __s) : _Base (__e, __s) {}
    };

  template<typename _Tp>
    struct _SClos<_ValArray, _Tp>
    : _SBase<_Array<_Tp> >
    {
      typedef  _SBase<_Array<_Tp> > _Base;
      typedef _Tp value_type;
      
      _SClos (_Array<_Tp> __a, const slice& __s) : _Base (__a, __s) {}
    };

_GLIBCXX_END_NAMESPACE

#endif /* _CPP_VALARRAY_BEFORE_H */
// Locale support (codecvt) -*- C++ -*-

// Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
//  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 bits/codecvt.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

//
// ISO C++ 14882: 22.2.1.5 Template class codecvt
//

// Written by Benjamin Kosnik <bkoz@redhat.com>

#ifndef _CODECVT_H
#define _CODECVT_H 1

#pragma GCC system_header

_GLIBCXX_BEGIN_NAMESPACE(std)

  /// Empty base class for codecvt facet [22.2.1.5].
  class codecvt_base
  {
  public:
    enum result
    {
      ok,
      partial,
      error,
      noconv
    };
  };

  /**
   *  @brief  Common base for codecvt functions.
   *
   *  This template class provides implementations of the public functions
   *  that forward to the protected virtual functions.
   *
   *  This template also provides abstract stubs for the protected virtual
   *  functions.
  */
  template<typename _InternT, typename _ExternT, typename _StateT>
    class __codecvt_abstract_base
    : public locale::facet, public codecvt_base
    {
    public:
      // Types:
      typedef codecvt_base::result	result;
      typedef _InternT			intern_type;
      typedef _ExternT			extern_type;
      typedef _StateT			state_type;

      // 22.2.1.5.1 codecvt members
      /**
       *  @brief  Convert from internal to external character set.
       *
       *  Converts input string of intern_type to output string of
       *  extern_type.  This is analogous to wcsrtombs.  It does this by
       *  calling codecvt::do_out.
       *
       *  The source and destination character sets are determined by the
       *  facet's locale, internal and external types.
       *
       *  The characters in [from,from_end) are converted and written to
       *  [to,to_end).  from_next and to_next are set to point to the
       *  character following the last successfully converted character,
       *  respectively.  If the result needed no conversion, from_next and
       *  to_next are not affected.
       *
       *  The @a state argument should be initialized if the input is at the
       *  beginning and carried from a previous call if continuing
       *  conversion.  There are no guarantees about how @a state is used.
       *
       *  The result returned is a member of codecvt_base::result.  If
       *  all the input is converted, returns codecvt_base::ok.  If no
       *  conversion is necessary, returns codecvt_base::noconv.  If
       *  the input ends early or there is insufficient space in the
       *  output, returns codecvt_base::partial.  Otherwise the
       *  conversion failed and codecvt_base::error is returned.
       *
       *  @param  state  Persistent conversion state data.
       *  @param  from  Start of input.
       *  @param  from_end  End of input.
       *  @param  from_next  Returns start of unconverted data.
       *  @param  to  Start of output buffer.
       *  @param  to_end  End of output buffer.
       *  @param  to_next  Returns start of unused output area.
       *  @return  codecvt_base::result.
      */
      result
      out(state_type& __state, const intern_type* __from,
	  const intern_type* __from_end, const intern_type*& __from_next,
	  extern_type* __to, extern_type* __to_end,
	  extern_type*& __to_next) const
      {
	return this->do_out(__state, __from, __from_end, __from_next,
			    __to, __to_end, __to_next);
      }

      /**
       *  @brief  Reset conversion state.
       *
       *  Writes characters to output that would restore @a state to initial
       *  conditions.  The idea is that if a partial conversion occurs, then
       *  the converting the characters written by this function would leave
       *  the state in initial conditions, rather than partial conversion
       *  state.  It does this by calling codecvt::do_unshift().
       *
       *  For example, if 4 external characters always converted to 1 internal
       *  character, and input to in() had 6 external characters with state
       *  saved, this function would write two characters to the output and
       *  set the state to initialized conditions.
       *
       *  The source and destination character sets are determined by the
       *  facet's locale, internal and external types.
       *
       *  The result returned is a member of codecvt_base::result.  If the
       *  state could be reset and data written, returns codecvt_base::ok.  If
       *  no conversion is necessary, returns codecvt_base::noconv.  If the
       *  output has insufficient space, returns codecvt_base::partial.
       *  Otherwise the reset failed and codecvt_base::error is returned.
       *
       *  @param  state  Persistent conversion state data.
       *  @param  to  Start of output buffer.
       *  @param  to_end  End of output buffer.
       *  @param  to_next  Returns start of unused output area.
       *  @return  codecvt_base::result.
      */
      result
      unshift(state_type& __state, extern_type* __to, extern_type* __to_end,
	      extern_type*& __to_next) const
      { return this->do_unshift(__state, __to,__to_end,__to_next); }

      /**
       *  @brief  Convert from external to internal character set.
       *
       *  Converts input string of extern_type to output string of
       *  intern_type.  This is analogous to mbsrtowcs.  It does this by
       *  calling codecvt::do_in.
       *
       *  The source and destination character sets are determined by the
       *  facet's locale, internal and external types.
       *
       *  The characters in [from,from_end) are converted and written to
       *  [to,to_end).  from_next and to_next are set to point to the
       *  character following the last successfully converted character,
       *  respectively.  If the result needed no conversion, from_next and
       *  to_next are not affected.
       *
       *  The @a state argument should be initialized if the input is at the
       *  beginning and carried from a previous call if continuing
       *  conversion.  There are no guarantees about how @a state is used.
       *
       *  The result returned is a member of codecvt_base::result.  If
       *  all the input is converted, returns codecvt_base::ok.  If no
       *  conversion is necessary, returns codecvt_base::noconv.  If
       *  the input ends early or there is insufficient space in the
       *  output, returns codecvt_base::partial.  Otherwise the
       *  conversion failed and codecvt_base::error is returned.
       *
       *  @param  state  Persistent conversion state data.
       *  @param  from  Start of input.
       *  @param  from_end  End of input.
       *  @param  from_next  Returns start of unconverted data.
       *  @param  to  Start of output buffer.
       *  @param  to_end  End of output buffer.
       *  @param  to_next  Returns start of unused output area.
       *  @return  codecvt_base::result.
      */
      result
      in(state_type& __state, const extern_type* __from,
	 const extern_type* __from_end, const extern_type*& __from_next,
	 intern_type* __to, intern_type* __to_end,
	 intern_type*& __to_next) const
      {
	return this->do_in(__state, __from, __from_end, __from_next,
			   __to, __to_end, __to_next);
      }

      int
      encoding() const throw()
      { return this->do_encoding(); }

      bool
      always_noconv() const throw()
      { return this->do_always_noconv(); }

      int
      length(state_type& __state, const extern_type* __from,
	     const extern_type* __end, size_t __max) const
      { return this->do_length(__state, __from, __end, __max); }

      int
      max_length() const throw()
      { return this->do_max_length(); }

    protected:
      explicit
      __codecvt_abstract_base(size_t __refs = 0) : locale::facet(__refs) { }

      virtual
      ~__codecvt_abstract_base() { }

      /**
       *  @brief  Convert from internal to external character set.
       *
       *  Converts input string of intern_type to output string of
       *  extern_type.  This function is a hook for derived classes to change
       *  the value returned.  @see out for more information.
      */
      virtual result
      do_out(state_type& __state, const intern_type* __from,
	     const intern_type* __from_end, const intern_type*& __from_next,
	     extern_type* __to, extern_type* __to_end,
	     extern_type*& __to_next) const = 0;

      virtual result
      do_unshift(state_type& __state, extern_type* __to,
		 extern_type* __to_end, extern_type*& __to_next) const = 0;

      virtual result
      do_in(state_type& __state, const extern_type* __from,
	    const extern_type* __from_end, const extern_type*& __from_next,
	    intern_type* __to, intern_type* __to_end,
	    intern_type*& __to_next) const = 0;

      virtual int
      do_encoding() const throw() = 0;

      virtual bool
      do_always_noconv() const throw() = 0;

      virtual int
      do_length(state_type&, const extern_type* __from,
		const extern_type* __end, size_t __max) const = 0;

      virtual int
      do_max_length() const throw() = 0;
    };

  /// @brief class codecvt [22.2.1.5].
  /// NB: Generic, mostly useless implementation.
  template<typename _InternT, typename _ExternT, typename _StateT>
    class codecvt
    : public __codecvt_abstract_base<_InternT, _ExternT, _StateT>
    {
    public:
      // Types:
      typedef codecvt_base::result	result;
      typedef _InternT			intern_type;
      typedef _ExternT			extern_type;
      typedef _StateT			state_type;

    protected:
      __c_locale			_M_c_locale_codecvt;

    public:
      static locale::id			id;

      explicit
      codecvt(size_t __refs = 0)
      : __codecvt_abstract_base<_InternT, _ExternT, _StateT> (__refs) { }

      explicit
      codecvt(__c_locale __cloc, size_t __refs = 0);

    protected:
      virtual
      ~codecvt() { }

      virtual result
      do_out(state_type& __state, const intern_type* __from,
	     const intern_type* __from_end, const intern_type*& __from_next,
	     extern_type* __to, extern_type* __to_end,
	     extern_type*& __to_next) const;

      virtual result
      do_unshift(state_type& __state, extern_type* __to,
		 extern_type* __to_end, extern_type*& __to_next) const;

      virtual result
      do_in(state_type& __state, const extern_type* __from,
	    const extern_type* __from_end, const extern_type*& __from_next,
	    intern_type* __to, intern_type* __to_end,
	    intern_type*& __to_next) const;

      virtual int
      do_encoding() const throw();

      virtual bool
      do_always_noconv() const throw();

      virtual int
      do_length(state_type&, const extern_type* __from,
		const extern_type* __end, size_t __max) const;

      virtual int
      do_max_length() const throw();
    };

  template<typename _InternT, typename _ExternT, typename _StateT>
    locale::id codecvt<_InternT, _Exter( (!("(#(nT, _StateT>::id;

  /// class codecvt<char, char, mbstate_t> specialization.
  template<>
    class codecvt<char, char, mbstate_t>
    : public __codecvt_abstract_base<char, char, mbstate_t>
    {
    public:
      // Types:
      typedef char			intern_type;
      typedef char			extern_type;
      typedef mbstate_t			state_type;

    protected:
      __c_locale			_M_c_locale_codecvt;

    public:
      static locale::id id;

      explicit
      codecvt(size_t __refs = 0);

      explicit
      codecvt(__c_locale __cloc, size_t __refs = 0);

    protected:
      virtual
      ~codecvt();

      virtual result
      do_out(state_type& __state, const intern_type* __from,
	     const intern_type* __from_end, const intern_type*& __from_next,
	     extern_type* __to, extern_type* __to_end,
	     extern_type*& __to_next) const;

      virtual result
      do_unshift(state_type& __state, extern_type* __to,
		 extern_type* __to_end, extern_type*& __to_next) const;

      virtual result
      do_in(state_type& __state, const extern_type* __from,
	    const extern_type* __from_end, const extern_type*& __from_next,
	    intern_type* __to, intern_type* __to_end,
	    intern_type*& __to_next) const;

      virtual int
      do_encoding() const throw();

      virtual bool
      do_always_noconv() const throw();

      virtual int
      do_length(state_type&, const extern_type* __from,
		const extern_type* __end, size_t __max) const;

      virtual int
      do_max_length() const throw();
  };

#ifdef _GLIBCXX_USE_WCHAR_T
  /// class codecvt<wchar_t, char, mbstate_t> specialization.
  template<>
    class codecvt<wchar_t, char, mbstate_t>
    : public __codecvt_abstract_base<wchar_t, char, mbstate_t>
    {
    public:
      // Types:
      typedef wchar_t			intern_type;
      typedef char			extern_type;
      typedef mbstate_t			state_type;

    protected:
      __c_locale			_M_c_locale_codecvt;

    public:
      static locale::id			id;

      explicit
      codecvt(size_t __refs = 0);

      explicit
      codecvt(__c_locale __cloc, size_t __refs = 0);

    protected:
      virtual
      ~codecvt();

      virtual result
      do_out(state_type& __state, const intern_type* __from,
	     const intern_type* __from_end, const intern_type*& __from_next,
	     extern_type* __to, extern_type* __to_end,
	     extern_type*& __to_next) const;

      virtual result
      do_unshift(state_type& __state,
		 extern_type* __to, extern_type* __to_end,
		 extern_type*& __to_next) const;

      virtual result
      do_in(state_type& __state,
	     const extern_type* __from, const extern_type* __from_end,
	     const extern_type*& __from_next,
	     intern_type* __to, intern_type* __to_end,
	     intern_type*& __to_next) const;

      virtual
      int do_encoding() const throw();

      virtual
      bool do_always_noconv() const throw();

      virtual
      int do_length(state_type&, const extern_type* __from,
		    const extern_type* __end, size_t __max) const;

      virtual int
      do_max_length() const throw();
    };
#endif //_GLIBCXX_USE_WCHAR_T

  /// class codecvt_byname [22.2.1.6].
  template<typename _InternT, typename _ExternT, typename _StateT>
    class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT>
    {
    public:
      explicit
      codecvt_byname(const char* __s, size_t __refs = 0)
      : codecvt<_InternT, _ExternT, _StateT>(__refs)
      {
	if (__builtin_strcmp(__s, "C") != 0
	    && __builtin_strcmp(__s, "POSIX") != 0)
	  {
	    this->_S_destroy_c_locale(this->_M_c_locale_codecvt);
	    this->_S_create_c_locale(this->_M_c_locale_codecvt, __s);
	  }
      }

    protected:
      virtual
      ~codecvt_byname() { }
    };

  // Inhibit implicit instantiations for required instantiations,
  // which are defined via explicit instantiations elsewhere.
  // NB: This syntax is a GNU extension.
#if _GLIBCXX_EXTERN_TEMPLATE
  extern template class codecvt_byname<char, char, mbstate_t>;

  extern template
    const codecvt<char, char, mbstate_t>&
    use_facet<codecvt<char, char, mbstate_t> >(const locale&);

  extern template
    bool
    has_facet<codecvt<char, char, mbstate_t> >(const locale&);

#ifdef _GLIBCXX_USE_WCHAR_T
  extern template class codecvt_byname<wchar_t, char, mbstate_t>;

  extern template
    const codecvt<wchar_t, char, mbstate_t>&
    use_facet<codecvt<wchar_t, char, mbstate_t> >(const locale&);

  extern template
    bool
    has_facet<codecvt<wchar_t, char, mbstate_t> >(const locale&);
#endif
#endif

_GLIBCXX_END_NAMESPACE

#endif // _CODECVT_H
// Components for manipulating sequences of characters -*- C++ -*-

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 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 basic_string.tcc
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

//
// ISO C++ 14882: 21  Strings library
//

// Written by Jason Merrill based upon the specification by Takanori Adachi
// in ANSI X3J16/94-0013R2.  Rewritten by Nathan Myers to ISO-14882.

#ifndef _BASIC_STRING_TCC
#define _BASIC_STRING_TCC 1

#pragma GCC system_header

#include <cxxabi-forced.h>

_GLIBCXX_BEGIN_NAMESPACE(std)

  template<typename _CharT, typename _Traits, typename _Alloc>
    const typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4;

  template<typename _CharT, typename _Traits, typename _Alloc>
    const _CharT
    basic_string<_CharT, _Traits, _Alloc>::
    _Rep::_S_terminal = _CharT();

  template<typename _CharT, typename _Traits, typename _Alloc>
    const typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::npos;

  // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string)
  // at static init time (before static ctors are run).
  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[
    (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) /
      sizeof(size_type)];

  // NB: This is the special case for Input Iterators, used in
  // istreambuf_iterators, etc.
  // Input Iterators have a cost structure very different from
  // pointers, calling for a different coding style.
  template<typename _CharT, typename _Traits, typename _Alloc>
    template<typename _InIterator>
      _CharT*
      basic_string<_CharT, _Traits, _Alloc>::
      _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
		   input_iterator_tag)
      {
#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
	if (__beg == __end && __a == _Alloc())
	  return _S_empty_rep()._M_refdata();
#endif
	// Avoid reallocation for common case.
	_CharT __buf[128];
	size_type __len = 0;
	while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
	  {
	    __buf[__len++] = *__beg;
	    ++__beg;
	  }
	_Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
	_M_copy(__r->_M_refdata(), __buf, __len);
	try
	  {
	    while (__beg != __end)
	      {
		if (__len == __r->_M_capacity)
		  {
		    // Allocate more space.
		    _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
		    _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
		    __r->_M_destroy(__a);
		    __r = __another;
		  }
		__r->_M_refdata()[__len++] = *__beg;
		++__beg;
	      }
	  }
	catch(...)
	  {
	    __r->_M_destroy(__a);
	    __throw_exception_again;
	  }
	__r->_M_set_length_and_sharable(__len);
	return __r->_M_refdata();
      }

  template<typename _CharT, typename _Traits, typename _Alloc>
    template <typename _InIterator>
      _CharT*
      basic_string<_CharT, _Traits, _Alloc>::
      _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
		   forward_iterator_tag)
      {
#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
	if (__beg == __end && __a == _Alloc())
	  return _S_empty_rep()._M_refdata();
#endif
	// NB: Not required, but considered best practice.
	if (__builtin_expect(__gnu_cxx::__is_null_pointer(__beg)
			     && __beg != __end, 0))
	  __throw_logic_error(__N("basic_string::_S_construct NULL not valid"));

	const size_type __dnew = static_cast<size_type>(std::distance(__beg,
								      __end));
	// Check for out_of_range and length_error exceptions.
	_Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
	try
	  { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
	catch(...)
	  {
	    __r->_M_destroy(__a);
	    __throw_exception_again;
	  }
	__r->_M_set_length_and_sharable(__dnew);
	return __r->_M_refdata();
      }

  template<typename _CharT, typename _Traits, typename _Alloc>
    _CharT*
    basic_string<_CharT, _Traits, _Alloc>::
    _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
    {
#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
      if (__n == 0 && __a == _Alloc())
	return _S_empty_rep()._M_refdata();
#endif
      // Check for out_of_range and length_error exceptions.
      _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
      if (__n)
	_M_assign(__r->_M_refdata(), __n, __c);

      __r->_M_set_length_and_sharable(__n);
      return __r->_M_refdata();
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(const basic_string& __str)
    : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(__str.get_allocator()),
					  __str.get_allocator()),
		  __str.get_allocator())
    { }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(const _Alloc& __a)
    : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a)
    { }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(const basic_string& __str, size_type __pos, size_type __n)
    : _M_dataplus(_S_construct(__str._M_data()
			       + __str._M_check(__pos,
						"basic_string::basic_string"),
			       __str._M_data() + __str._M_limit(__pos, __n)
			       + __pos, _Alloc()), _Alloc())
    { }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(const basic_string& __str, size_type __pos,
		 size_type __n, const _Alloc& __a)
    : _M_dataplus(_S_construct(__str._M_data()
			       + __str._M_check(__pos,
						"basic_string::basic_string"),
			       __str._M_data() + __str._M_limit(__pos, __n)
			       + __pos, __a), __a)
    { }

  // TBD: DPG annotate
  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(const _CharT* __s, size_type __n, const _Alloc& __a)
    : _M_dataplus(_S_construct(__s, __s + __n, __a), __a)
    { }

  // TBD: DPG annotate
  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(const _CharT* __s, const _Alloc& __a)
    : _M_dataplus(_S_construct(__s, __s ? __s + traits_type::length(__s) :
			       __s + npos, __a), __a)
    { }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(size_type __n, _CharT __c, const _Alloc& __a)
    : _M_dataplus(_S_construct(__n, __c, __a), __a)
    { }

  // TBD: DPG annotate
  template<typename _CharT, typename _Traits, typename _Alloc>
    template<typename _InputIterator>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(_InputIterator __beg, _InputIterator __end, const _Alloc& __a)
    : _M_dataplus(_S_construct(__beg, __end, __a), __a)
    { }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    assign(const basic_string& __str)
    {
      if (_M_rep() != __str._M_rep())
	{
	  // XXX MT
	  const allocator_type __a = this->get_allocator();
	  _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
	  _M_rep()->_M_dispose(__a);
	  _M_data(__tmp);
	}
      return *this;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    assign(const _CharT* __s, size_type __n)
    {
      __glibcxx_requires_string_len(__s, __n);
      _M_check_length(this->size(), __n, "basic_string::assign");
      if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
	return _M_replace_safe(size_type(0), this->size(), __s, __n);
      else
	{
	  // Work in-place.
	  const size_type __pos = __s - _M_data();
	  if (__pos >= __n)
	    _M_copy(_M_data(), __s, __n);
	  else if (__pos)
	    _M_move(_M_data(), __s, __n);
	  _M_rep()->_M_set_length_and_sharable(__n);
	  return *this;
	}
     }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    append(size_type __n, _CharT __c)
    {
      if (__n)
	{
	  _M_check_length(size_type(0), __n, "basic_string::append");	  
	  const size_type __len = __n + this->size();
	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
	    this->reserve(__len);
	  _M_assign(_M_data() + this->size(), __n, __c);
	  _M_rep()->_M_set_length_and_sharable(__len);
	}
      return *this;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    append(const _CharT* __s, size_type __n)
    {
      __glibcxx_requires_string_len(__s, __n);
      if (__n)
	{
	  _M_check_length(size_type(0), __n, "basic_string::append");
	  const size_type __len = __n + this->size();
	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
	    {
	      if (_M_disjunct(__s))
		this->reserve(__len);
	      else
		{
		  const size_type __off = __s - _M_data();
		  this->reserve(__len);
		  __s = _M_data() + __off;
		}
	    }
	  _M_copy(_M_data() + this->size(), __s, __n);
	  _M_rep()->_M_set_length_and_sharable(__len);
	}
      return *this;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    append(const basic_string& __str)
    {
      const size_type __size = __str.size();
      if (__size)
	{
	  const size_type __len = __size + this->size();
	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
	    this->reserve(__len);
	  _M_copy(_M_data() + this->size(), __str._M_data(), __size);
	  _M_rep()->_M_set_length_and_sharable(__len);
	}
      return *this;
    }    

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    append(const basic_string& __str, size_type __pos, size_type __n)
    {
      __str._M_check(__pos, "basic_string::append");
      __n = __str._M_limit(__pos, __n);
      if (__n)
	{
	  const size_type __len = __n + this->size();
	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
	    this->reserve(__len);
	  _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n);
	  _M_rep()->_M_set_length_and_sharable(__len);	  
	}
      return *this;
    }

   template<typename _CharT, typename _Traits, typename _Alloc>
     basic_string<_CharT, _Traits, _Alloc>&
     basic_string<_CharT, _Traits, _Alloc>::
     insert(size_type __pos, const _CharT* 1(2(3(4(5(6(7(8(9(:(;(<(=(>(?(@(A(B(C(D(E(F(G(H(I(J(__s, size_type __n)
     {
       __glibcxx_requires_string_len(__s, __n);
       _M_check(__pos, "basic_string::insert");
       _M_check_length(size_type(0), __n, "basic_string::insert");
       if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
         return _M_replace_safe(__pos, size_type(0), __s, __n);
       else
         {
           // Work in-place.
           const size_type __off = __s - _M_data();
           _M_mutate(__pos, 0, __n);
           __s = _M_data() + __off;
           _CharT* __p = _M_data() + __pos;
           if (__s  + __n <= __p)
             _M_copy(__p, __s, __n);
           else if (__s >= __p)
             _M_copy(__p, __s + __n, __n);
           else
             {
	       const size_type __nleft = __p - __s;
               _M_copy(__p, __s, __nleft);
               _M_copy(__p + __nleft, __p + __n, __n - __nleft);
             }
           return *this;
         }
     }

   template<typename _CharT, typename _Traits, typename _Alloc>
     basic_string<_CharT, _Traits, _Alloc>&
     basic_string<_CharT, _Traits, _Alloc>::
     replace(size_type __pos, size_type __n1, const _CharT* __s,
	     size_type __n2)
     {
       __glibcxx_requires_string_len(__s, __n2);
       _M_check(__pos, "basic_string::replace");
       __n1 = _M_limit(__pos, __n1);
       _M_check_length(__n1, __n2, "basic_string::replace");
       bool __left;
       if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
         return _M_replace_safe(__pos, __n1, __s, __n2);
       else if ((__left = __s + __n2 <= _M_data() + __pos)
		|| _M_data() + __pos + __n1 <= __s)
	 {
	   // Work in-place: non-overlapping case.
	   size_type __off = __s - _M_data();
	   __left ? __off : (__off += __n2 - __n1);
	   _M_mutate(__pos, __n1, __n2);
	   _M_copy(_M_data() + __pos, _M_data() + __off, __n2);
	   return *this;
	 }
       else
	 {
	   // Todo: overlapping case.
	   const basic_string __tmp(__s, __n2);
	   return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2);
	 }
     }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::_Rep::
    _M_destroy(const _Alloc& __a) throw ()
    {
      const size_type __size = sizeof(_Rep_base) +
	                       (this->_M_capacity + 1) * sizeof(_CharT);
      _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::
    _M_leak_hard()
    {
#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
      if (_M_rep() == &_S_empty_rep())
	return;
#endif
      if (_M_rep()->_M_is_shared())
	_M_mutate(0, 0, 0);
      _M_rep()->_M_set_leaked();
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::
    _M_mutate(size_type __pos, size_type __len1, size_type __len2)
    {
      const size_type __old_size = this->size();
      const size_type __new_size = __old_size + __len2 - __len1;
      const size_type __how_much = __old_size - __pos - __len1;

      if (__new_size > this->capacity() || _M_rep()->_M_is_shared())
	{
	  // Must reallocate.
	  const allocator_type __a = get_allocator();
	  _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a);

	  if (__pos)
	    _M_copy(__r->_M_refdata(), _M_data(), __pos);
	  if (__how_much)
	    _M_copy(__r->_M_refdata() + __pos + __len2,
		    _M_data() + __pos + __len1, __how_much);

	  _M_rep()->_M_dispose(__a);
	  _M_data(__r->_M_refdata());
	}
      else if (__how_much && __len1 != __len2)
	{
	  // Work in-place.
	  _M_move(_M_data() + __pos + __len2,
		  _M_data() + __pos + __len1, __how_much);
	}
      _M_rep()->_M_set_length_and_sharable(__new_size);
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::
    reserve(size_type __res)
    {
      if (__res != this->capacity() || _M_rep()->_M_is_shared())
        {
	  // Make sure we don't shrink below the current size
	  if (__res < this->size())
	    __res = this->size();
	  const allocator_type __a = get_allocator();
	  _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
	  _M_rep()->_M_dispose(__a);
	  _M_data(__tmp);
        }
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::
    swap(basic_string& __s)
    {
      if (_M_rep()->_M_is_leaked())
	_M_rep()->_M_set_sharable();
      if (__s._M_rep()->_M_is_leaked())
	__s._M_rep()->_M_set_sharable();
      if (this->get_allocator() == __s.get_allocator())
	{
	  _CharT* __tmp = _M_data();
	  _M_data(__s._M_data());
	  __s._M_data(__tmp);
	}
      // The code below can usually be optimized away.
      else
	{
	  const basic_string __tmp1(_M_ibegin(), _M_iend(),
				    __s.get_allocator());
	  const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
				    this->get_allocator());
	  *this = __tmp2;
	  __s = __tmp1;
	}
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::_Rep*
    basic_string<_CharT, _Traits, _Alloc>::_Rep::
    _S_create(size_type __capacity, size_type __old_capacity,
	      const _Alloc& __alloc)
    {
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 83.  String::npos vs. string::max_size()
      if (__capacity > _S_max_size)
	__throw_length_error(__N("basic_string::_S_create"));

      // The standard places no restriction on allocating more memory
      // than is strictly needed within this layer at the moment or as
      // requested by an explicit application call to reserve().

      // Many malloc implementations perform quite poorly when an
      // application attempts to allocate memory in a stepwise fashion
      // growing each allocation size by only 1 char.  Additionally,
      // it makes little sense to allocate less linear memory than the
      // natural blocking size of the malloc implementation.
      // Unfortunately, we would need a somewhat low-level calculation
      // with tuned parameters to get this perfect for any particular
      // malloc implementation.  Fortunately, generalizations about
      // common features seen among implementations seems to suffice.

      // __pagesize need not match the actual VM page size for good
      // results in practice, thus we pick a common value on the low
      // side.  __malloc_header_size is an estimate of the amount of
      // overhead per memory allocation (in practice seen N * sizeof
      // (void*) where N is 0, 2 or 4).  According to folklore,
      // picking this value on the high side is better than
      // low-balling it (especially when this algorithm is used with
      // malloc implementations that allocate memory blocks rounded up
      // to a size which is a power of 2).
      const size_type __pagesize = 4096;
      const size_type __malloc_header_size = 4 * sizeof(void*);

      // The below implements an exponential growth policy, necessary to
      // meet amortized linear time requirements of the library: see
      // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
      // It's active for allocations requiring an amount of memory above
      // system pagesize. This is consistent with the requirements of the
      // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
      if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
	__capacity = 2 * __old_capacity;

      // NB: Need an array of char_type[__capacity], plus a terminating
      // null char_type() element, plus enough for the _Rep data structure.
      // Whew. Seemingly so needy, yet so elemental.
      size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);

      const size_type __adj_size = __size + __malloc_header_size;
      if (__adj_size > __pagesize && __capacity > __old_capacity)
	{
	  const size_type __extra = __pagesize - __adj_size % __pagesize;
	  __capacity += __extra / sizeof(_CharT);
	  // Never allocate a string bigger than _S_max_size.
	  if (__capacity > _S_max_size)
	    __capacity = _S_max_size;
	  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
	}

      // NB: Might throw, but no worries about a leak, mate: _Rep()
      // does not throw.
      void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
      _Rep *__p = new (__place) _Rep;
      __p->_M_capacity = __capacity;
      // ABI compatibility - 3.4.x set in _S_create both
      // _M_refcount and _M_length.  All callers of _S_create
      // in basic_string.tcc then set just _M_length.
      // In 4.0.x and later both _M_refcount and _M_length
      // are initialized in the callers, unfortunately we can
      // have 3.4.x compiled code with _S_create callers inlined
      // calling 4.0.x+ _S_create.
      __p->_M_set_sharable();
      return __p;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    _CharT*
    basic_string<_CharT, _Traits, _Alloc>::_Rep::
    _M_clone(const _Alloc& __alloc, size_type __res)
    {
      // Requested capacity of the clone.
      const size_type __requested_cap = this->_M_length + __res;
      _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
				  __alloc);
      if (this->_M_length)
	_M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length);

      __r->_M_set_length_and_sharable(this->_M_length);
      return __r->_M_refdata();
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::
    resize(size_type __n, _CharT __c)
    {
      const size_type __size = this->size();
      _M_check_length(__size, __n, "basic_string::resize");
      if (__size < __n)
	this->append(__n - __size, __c);
      else if (__n < __size)
	this->erase(__n);
      // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    template<typename _InputIterator>
      basic_string<_CharT, _Traits, _Alloc>&
      basic_string<_CharT, _Traits, _Alloc>::
      _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
			  _InputIterator __k2, __false_type)
      {
	const basic_string __s(__k1, __k2);
	const size_type __n1 = __i2 - __i1;
	_M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");
	return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(),
			       __s.size());
      }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
		   _CharT __c)
    {
      _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
      _M_mutate(__pos1, __n1, __n2);
      if (__n2)
	_M_assign(_M_data() + __pos1, __n2, __c);
      return *this;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>&
    basic_string<_CharT, _Traits, _Alloc>::
    _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
		    size_type __n2)
    {
      _M_mutate(__pos1, __n1, __n2);
      if (__n2)
	_M_copy(_M_data() + __pos1, __s, __n2);
      return *this;
    }
   
  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>
    operator+(const _CharT* __lhs,
	      const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    {
      __glibcxx_requires_string(__lhs);
      typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
      typedef typename __string_type::size_type	  __size_type;
      const __size_type __len = _Traits::length(__lhs);
      __string_type __str;
      __str.reserve(__len + __rhs.size());
      __str.append(__lhs, __len);
      __str.append(__rhs);
      return __str;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>
    operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    {
      typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
      typedef typename __string_type::size_type	  __size_type;
      __string_type __str;
      const __size_type __len = __rhs.size();
      __str.reserve(__len + 1);
      __str.append(__size_type(1), __lhs);
      __str.append(__rhs);
      return __str;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    copy(_CharT* __s, size_type __n, size_type __pos) const
    {
      _M_check(__pos, "basic_string::copy");
      __n = _M_limit(__pos, __n);
      __glibcxx_requires_string_len(__s, __n);
      if (__n)
	_M_copy(__s, _M_data() + __pos, __n);
      // 21.3.5.7 par 3: do not append null.  (good.)
      return __n;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    find(const _CharT* __s, size_type __pos, size_type __n) const
    {
      __glibcxx_requires_string_len(__s, __n);
      const size_type __size = this->size();
      const _CharT* __data = _M_data();

      if (__n == 0)
	return __pos <= __size ? __pos : npos;

      if (__n <= __size)
	{
	  for (; __pos <= __size - __n; ++__pos)
	    if (traits_type::eq(__data[__pos], __s[0])
		&& traits_type::compare(__data + __pos + 1,
					__s + 1, __n - 1) == 0)
	      return __pos;
	}
      return npos;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    find(_CharT __c, size_type __pos) const
    {
      size_type __ret = npos;
      const size_type __size = this->size();
      if (__pos < __size)
	{
	  const _CharT* __data = _M_data();
	  const size_type __n = __size - __pos;
	  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
	  if (__p)
	    __ret = __p - __data;
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    rfind(const _CharT* __s, size_type __pos, size_type __n) const
    {
      __glibcxx_requires_string_len(__s, __n);
      const size_type __size = this->size();
      if (__n <= __size)
	{
	  __pos = std::min(size_type(__size - __n), __pos);
	  const _CharT* __data = _M_data();
	  do
	    {
	      if (traits_type::compare(__data + __pos, __s, __n) == 0)
		return __pos;
	    }
	  while (__pos-- > 0);
	}
      return npos;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    rfind(_CharT __c, size_type __pos) const
    {
      size_type __size = this->size();
      if (__size)
	{
	  if (--__size > __pos)
	    __size = __pos;
	  for (++__size; __size-- > 0; )
	    if (traits_type::eq(_M_data()[__size], __c))
	      return __size;
	}
      return npos;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    typename basic_string<_CharT, _Traits, _Alloc>::size_type
    basic_string<_CharT, _Traits, _Alloc>::
    find_first_of(const _CharT* __s, s