string.tcc

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// Components for manipulating sequences of characters -*- C++ -*-

// Copyright (C) 1997-1999 Cygnus Solutions
//
// 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// 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.

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

// This file is included by <string>.  It is not meant to be included
// separately.

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

#ifndef _CPP_BITS_STRING_TCC
#define _CPP_BITS_STRING_TCC 1

namespace std
{

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

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

  // 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 _InIter>
      _CharT*
      basic_string<_CharT, _Traits, _Alloc>::
      _S_construct(_InIter __beg, _InIter __end, const _Alloc& __a,
		   input_iterator_tag)
      {
	if (__beg == __end && __a == _Alloc())
	  return _S_empty_rep()._M_refcopy();
	// Avoid reallocation for common case.
	_CharT __buf[100];
	size_type __i = 0;
	while (__beg != __end && __i < sizeof(__buf) / sizeof(_CharT))
	  { 
	    __buf[__i++] = *__beg; 
	    ++__beg; 
	  }
	_Rep* __r = _Rep::_S_create(__i, __a);
	traits_type::copy(__r->_M_refdata(), __buf, __i);
	__r->_M_length = __i;
	try {
	  // NB: this loop looks precisely this way because
	  // it avoids comparing __beg != __end any more
	  // than strictly necessary; != might be expensive!
	  for (;;)
	    {
	      _CharT* __p = __r->_M_refdata() + __r->_M_length;
	      _CharT* __last = __r->_M_refdata() + __r->_M_capacity;
	      for (;;)
		{
		  if (__beg == __end)
		    {
		      __r->_M_length = __p - __r->_M_refdata();
		      *__p = _Rep::_S_terminal;       // grrr.
		      return __r->_M_refdata();
		    }
		  if (__p == __last)
		    break;
		  *__p++ = *__beg; 
		  ++__beg;
		}
	      // Allocate more space.
	      size_type __len = __p - __r->_M_refdata();
	      _Rep* __another = _Rep::_S_create(__len + 1, __a);
	      traits_type::copy(__another->_M_refdata(), 
				__r->_M_refdata(), __len);
	      __r->_M_destroy(__a);
	      __r = __another;
	      __r->_M_length = __len;
	    }
	}
	catch (...) {
	    __r->_M_destroy(__a); 
	    throw;
	}
	return 0;
      }

  template<typename _CharT, typename _Traits, typename _Alloc>
    template <class _InIter>
      _CharT*
      basic_string<_CharT,_Traits,_Alloc>::
      _S_construct(_InIter __beg, _InIter __end, const _Alloc& __a, 
		   forward_iterator_tag)
      {
	size_type __dnew = static_cast<size_type>(distance(__beg, __end));

	if (__beg == __end && __a == _Alloc())
	  return _S_empty_rep()._M_refcopy();

	// Check for out_of_range and length_error exceptions.
	_Rep* __r = _Rep::_S_create(__dnew, __a);
	try { 
	  _S_copy_chars(__r->_M_refdata(), __beg, __end); 
	}
	catch (...) { 
	  __r->_M_destroy(__a); 
	  throw; 
	}
	__r->_M_length = __dnew;

	__r->_M_refdata()[__dnew] = _Rep::_S_terminal;  // grrr.
	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)
    {
      if (__n == 0 && __a == _Alloc())
	return _S_empty_rep()._M_refcopy();

      // Check for out_of_range and length_error exceptions.
      _Rep* __r = _Rep::_S_create(__n, __a);
      try { 
	if (__n) 
	  traits_type::assign(__r->_M_refdata(), __n, __c); 
      }
      catch (...) { 
	__r->_M_destroy(__a); 
	throw; 
      }
      __r->_M_length = __n;
      __r->_M_refdata()[__n] = _Rep::_S_terminal;  // grrr
      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())
    { }

  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_check(__pos), 
			       __str._M_fold(__pos, __n), _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_check(__pos), 
			       __str._M_fold(__pos, __n), __a), __a)
    { }

  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 + min(traits_type::length(__s), __n), 
			       __a), __a)
    { }

  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 + traits_type::length(__s), __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)
    { }
 
  template<typename _CharT, typename _Traits, typename _Alloc>
    template<typename _InputIter>
    basic_string<_CharT, _Traits, _Alloc>::
    basic_string(_InputIter __beg, _InputIter __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
	  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>
    void
    basic_string<_CharT, _Traits, _Alloc>::_Rep::
    _M_destroy(const _Alloc& __a) throw ()
    {
      size_type __size = sizeof(_Rep) + (_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()
    {
      if (_M_rep()->_M_state > 0) 
	_M_mutate(0, 0, 0);
      _M_rep()->_M_state = -1;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::
    _M_mutate(size_type __pos, size_type __len1, size_type __len2)
    {
      size_type       __old_size = this->size();
      const size_type __new_size = __old_size + __len2 - __len1;
      const _CharT*        __src = _M_data()  + __pos + __len1;
      const size_type __how_much = __old_size - __pos - __len1;
      
      if (_M_rep()->_M_state > 0 || __new_size > capacity())
	{
	  // Must reallocate.
	  allocator_type __a = get_allocator();
	  _Rep* __r = _Rep::_S_create(__new_size, __a);
	  try {
	    if (__pos)
	      traits_type::copy(__r->_M_refdata(), _M_data(), __pos);
	    if (__how_much)
	      traits_type::copy(__r->_M_refdata() + __pos + __len2, 
				__src, __how_much);
	  }
	  catch (...) { 
	    __r->_M_dispose(get_allocator()); 
	    throw; 
	  }
	  _M_rep()->_M_dispose(__a);
	  _M_data(__r->_M_refdata());
      }
      else if (__how_much)
	{
	  // Work in-place
	  traits_type::move(_M_data() + __pos + __len2, __src, __how_much);
	}
      _M_rep()->_M_state = 0;
      _M_rep()->_M_length = __new_size;
      _M_data()[__new_size] = _Rep::_S_terminal; // grrr. (per 21.3.4)
    // You cannot leave those LWG people alone for a second.
    }
  
  template<typename _CharT, typename _Traits, typename _Alloc>
    void
    basic_string<_CharT, _Traits, _Alloc>::reserve(size_type __res)
    {
      if (__res > this->capacity() || _M_rep()->_M_state > 0)
        {
	  __LENGTHERROR(__res > this->max_size());
	  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_state < 0) 
	_M_rep()->_M_state = 0;
      if (__s._M_rep()->_M_state < 0) 
	__s._M_rep()->_M_state = 0;
      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 
	{
	  basic_string __tmp1(_M_ibegin(), _M_iend(), __s.get_allocator());
	  basic_string __tmp2(__s._M_ibegin(), __s._M_iend(), 
			      this->get_allocator());
	  *this = __tmp2;
	  __s = __tmp1;
	}
    }

#ifdef _GLIBCPP_ALLOC_CONTROL
  template<typename _CharT, typename _Traits, typename _Alloc>
    bool (*basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_excess_slop) 
    (size_t, size_t) = 
    basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_default_excess;
#endif

  template<typename _CharT, typename _Traits, typename _Alloc>
    basic_string<_CharT, _Traits, _Alloc>::_Rep*
    basic_string<_CharT, _Traits, _Alloc>::_Rep::
    _S_create(size_t __capacity, const _Alloc& __alloc)
    {
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
      // 83.  String::npos vs. string::max_size()
      typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
      __LENGTHERROR(__capacity > _S_max_size);
#else
      __LENGTHERROR(__capacity == npos);
#endif

      // 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_t __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;
      __p->_M_state = 0;  // one reference
      __p->_M_length = 0;
      return __p;
    }

  template<typename _CharT, typename _Traits, typename _Alloc>
    _CharT*
    basic_string<_CharT, _Traits, _Alloc>::_Rep::
    _M_clone(const _Alloc& __alloc, size_type __res)
    {
      _Rep* __r = _Rep::_S_create(_M_length + __res, __alloc);
      if (_M_length)
	{
	  try { 
	    traits_type::copy(__r->_M_refdata(), _M_refdata(), _M_length); 
	  }
	  catch (...)  { 
	    __r->_M_destroy(__alloc); 
	    throw; 
	  }
	}
      __r->_M_length = _M_length;
      return __r->_M_refdata();
    }
  
  template<typename _CharT, typename _Traits, typename _Alloc>
  inline bool
#ifdef _GLIBCPP_ALLOC_CONTROL