_string.h

stl的源码

/*
 * Copyright (c) 1997-1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1999
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

#ifndef _STLP_INTERNAL_STRING_H
#define _STLP_INTERNAL_STRING_H

#ifndef _STLP_INTERNAL_ALLOC_H
#  include <stl/_alloc.h>
#endif

#ifndef _STLP_STRING_FWD_H
#  include <stl/_string_fwd.h>
#endif

#ifndef _STLP_INTERNAL_FUNCTION_BASE_H
#  include <stl/_function_base.h>
#endif

#ifndef _STLP_INTERNAL_ALGOBASE_H
#  include <stl/_algobase.h>
#endif

#ifndef _STLP_INTERNAL_ITERATOR_H
#  include <stl/_iterator.h>
#endif

#ifndef _STLP_INTERNAL_UNINITIALIZED_H
#  include <stl/_uninitialized.h>
#endif

#if defined (_STLP_USE_TEMPLATE_EXPRESSION)
#  include <stl/_string_sum.h>
#endif /* _STLP_USE_TEMPLATE_EXPRESSION */

#if defined (__MWERKS__) && ! defined (_STLP_USE_OWN_NAMESPACE)

// MSL implementation classes expect to see the definition of streampos
// when this header is included. We expect this to be fixed in later MSL
// implementations
#  if !defined( __MSL_CPP__ ) || __MSL_CPP__ < 0x4105
#    include <stl/msl_string.h>
#  endif
#endif // __MWERKS__

/*
 * Standard C++ string class.  This class has performance
 * characteristics very much like vector<>, meaning, for example, that
 * it does not perform reference-count or copy-on-write, and that
 * concatenation of two strings is an O(N) operation.

 * There are three reasons why basic_string is not identical to
 * vector.
 * First, basic_string always stores a null character at the end;
 * this makes it possible for c_str to be a fast operation.
 * Second, the C++ standard requires basic_string to copy elements
 * using char_traits<>::assign, char_traits<>::copy, and
 * char_traits<>::move.  This means that all of vector<>'s low-level
 * operations must be rewritten.  Third, basic_string<> has a lot of
 * extra functions in its interface that are convenient but, strictly
 * speaking, redundant.
 */

#include <stl/_string_base.h>

_STLP_BEGIN_NAMESPACE

// ------------------------------------------------------------
// Class basic_string.

// Class invariants:
// (1) [start, finish) is a valid range.
// (2) Each iterator in [start, finish) points to a valid object
//     of type value_type.
// (3) *finish is a valid object of type value_type; when
//     value_type is not a POD it is value_type().
// (4) [finish + 1, end_of_storage) is a valid range.
// (5) Each iterator in [finish + 1, end_of_storage) points to
//     unininitialized memory.

// Note one important consequence: a string of length n must manage
// a block of memory whose size is at least n + 1.

_STLP_MOVE_TO_PRIV_NAMESPACE
struct _String_reserve_t {};
_STLP_MOVE_TO_STD_NAMESPACE

#if defined (_STLP_USE_MSVC6_MEM_T_BUG_WORKAROUND)
#  define basic_string _STLP_NO_MEM_T_NAME(str)
#elif defined (_STLP_DEBUG)
#  define basic_string _STLP_NON_DBG_NAME(str)
#endif

#if defined (basic_string)
_STLP_MOVE_TO_PRIV_NAMESPACE
#endif

#if defined (__DMC__)
#  define _STLP_PRIVATE public
#elif defined (_STLP_USE_MSVC6_MEM_T_BUG_WORKAROUND)
#  define _STLP_PRIVATE protected
#else
#  define _STLP_PRIVATE private
#endif

template <class _CharT, class _Traits, class _Alloc>
class basic_string : _STLP_PRIVATE _STLP_PRIV _String_base<_CharT,_Alloc>
#if defined (_STLP_USE_PARTIAL_SPEC_WORKAROUND) && !defined (basic_string)
                   , public __stlport_class<basic_string<_CharT, _Traits, _Alloc> >
#endif
{
_STLP_PRIVATE:                        // Private members inherited from base.
  typedef _STLP_PRIV _String_base<_CharT,_Alloc> _Base;
  typedef basic_string<_CharT, _Traits, _Alloc> _Self;

public:
  typedef _CharT value_type;
  typedef _Traits traits_type;

  typedef value_type* pointer;
  typedef const value_type* const_pointer;
  typedef value_type& reference;
  typedef const value_type& const_reference;
  typedef typename _Base::size_type size_type;
  typedef ptrdiff_t difference_type;
  typedef random_access_iterator_tag _Iterator_category;

  typedef const value_type* const_iterator;
  typedef value_type*       iterator;

  _STLP_DECLARE_RANDOM_ACCESS_REVERSE_ITERATORS;

#include <stl/_string_npos.h>

  typedef _STLP_PRIV _String_reserve_t _Reserve_t;

public:                         // Constructor, destructor, assignment.
  typedef typename _Base::allocator_type allocator_type;

  allocator_type get_allocator() const
  { return _STLP_CONVERT_ALLOCATOR((const allocator_type&)this->_M_start_of_storage, _CharT); }

#if !defined (_STLP_DONT_SUP_DFLT_PARAM)
  explicit basic_string(const allocator_type& __a = allocator_type())
#else
  basic_string()
      : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type(), _Base::_DEFAULT_SIZE)
  { _M_terminate_string(); }
  explicit basic_string(const allocator_type& __a)
#endif
      : _STLP_PRIV _String_base<_CharT,_Alloc>(__a, _Base::_DEFAULT_SIZE)
  { _M_terminate_string(); }

#if !defined (_STLP_DONT_SUP_DFLT_PARAM)
  basic_string(_Reserve_t, size_t __n,
               const allocator_type& __a = allocator_type())
#else
  basic_string(_Reserve_t, size_t __n)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type(), __n + 1)
  { _M_terminate_string(); }
  basic_string(_Reserve_t, size_t __n, const allocator_type& __a)
#endif
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__a, __n + 1)
  { _M_terminate_string(); }

  basic_string(const _Self&);

#if !defined (_STLP_DONT_SUP_DFLT_PARAM)
  basic_string(const _Self& __s, size_type __pos, size_type __n = npos,
               const allocator_type& __a = allocator_type())
#else
  basic_string(const _Self& __s, size_type __pos)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type()) {
    if (__pos > __s.size())
      this->_M_throw_out_of_range();
    else
      _M_range_initialize(__s._M_Start() + __pos, __s._M_Finish());
  }
  basic_string(const _Self& __s, size_type __pos, size_type __n)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type()) {
    if (__pos > __s.size())
      this->_M_throw_out_of_range();
    else
      _M_range_initialize(__s._M_Start() + __pos,
                          __s._M_Start() + __pos + (min) (__n, __s.size() - __pos));
  }
  basic_string(const _Self& __s, size_type __pos, size_type __n,
               const allocator_type& __a)
#endif
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__a) {
    if (__pos > __s.size())
      this->_M_throw_out_of_range();
    else
      _M_range_initialize(__s._M_Start() + __pos,
                          __s._M_Start() + __pos + (min) (__n, __s.size() - __pos));
  }

#if !defined (_STLP_DONT_SUP_DFLT_PARAM)
  basic_string(const _CharT* __s, size_type __n,
               const allocator_type& __a = allocator_type())
#else
  basic_string(const _CharT* __s, size_type __n)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type()) {
      _STLP_FIX_LITERAL_BUG(__s)
      _M_range_initialize(__s, __s + __n);
    }
  basic_string(const _CharT* __s, size_type __n, const allocator_type& __a)
#endif
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__a) {
      _STLP_FIX_LITERAL_BUG(__s)
      _M_range_initialize(__s, __s + __n);
    }

#if !defined (_STLP_DONT_SUP_DFLT_PARAM)
  basic_string(const _CharT* __s,
               const allocator_type& __a = allocator_type());
#else
  basic_string(const _CharT* __s);
  basic_string(const _CharT* __s, const allocator_type& __a);
#endif

#if !defined (_STLP_DONT_SUP_DFLT_PARAM)
  basic_string(size_type __n, _CharT __c,
               const allocator_type& __a = allocator_type())
#else
  basic_string(size_type __n, _CharT __c)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type(), __n + 1) {
    this->_M_finish = _STLP_PRIV __uninitialized_fill_n(this->_M_Start(), __n, __c);
    _M_terminate_string();
  }
  basic_string(size_type __n, _CharT __c, const allocator_type& __a)
#endif
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__a, __n + 1) {
    this->_M_finish = _STLP_PRIV __uninitialized_fill_n(this->_M_Start(), __n, __c);
    _M_terminate_string();
  }

#if !defined (_STLP_NO_MOVE_SEMANTIC)
  basic_string(__move_source<_Self> src)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__move_source<_Base>(src.get())) {}
#endif

  // Check to see if _InputIterator is an integer type.  If so, then
  // it can't be an iterator.
#if defined (_STLP_MEMBER_TEMPLATES) && !defined (_STLP_USE_MSVC6_MEM_T_BUG_WORKAROUND)
  template <class _InputIterator>
  basic_string(_InputIterator __f, _InputIterator __l,
               const allocator_type & __a _STLP_ALLOCATOR_TYPE_DFL)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__a) {
    typedef typename _IsIntegral<_InputIterator>::_Ret _Integral;
    _M_initialize_dispatch(__f, __l, _Integral());
  }
#  if defined (_STLP_NEEDS_EXTRA_TEMPLATE_CONSTRUCTORS)
  template <class _InputIterator>
  basic_string(_InputIterator __f, _InputIterator __l)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type()) {
    typedef typename _IsIntegral<_InputIterator>::_Ret _Integral;
    _M_initialize_dispatch(__f, __l, _Integral());
  }
#  endif
#else
#  if !defined (_STLP_USE_MSVC6_MEM_T_BUG_WORKAROUND)
  basic_string(const _CharT* __f, const _CharT* __l,
               const allocator_type& __a _STLP_ALLOCATOR_TYPE_DFL)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(__a) {
    _STLP_FIX_LITERAL_BUG(__f)  _STLP_FIX_LITERAL_BUG(__l)
    _M_range_initialize(__f, __l);
  }
#    if defined (_STLP_NEEDS_EXTRA_TEMPLATE_CONSTRUCTORS)
  basic_string(const _CharT* __f, const _CharT* __l)
    : _STLP_PRIV _String_base<_CharT,_Alloc>(allocator_type()) {
    _STLP_FIX_LITERAL_BUG(__f)  _STLP_FIX_LITERAL_BUG(__l)
    _M_range_initialize(__f, __l);
  }
#    endif
#  endif
#  if defined (_STLP_USE_MSVC6_MEM_T_BUG_WORKAROUND)
  /* We need an additionnal constructor to build an empty string without
   * any allocation or termination char*/
protected:
  struct _CalledFromWorkaround_t {};
  basic_string(_CalledFromWorkaround_t, const allocator_type &__a)
    : _String_base<_CharT,_Alloc>(__a) {}
#  endif
#endif

_STLP_PRIVATE:
  size_type _M_compute_next_size(size_type __n) {
    const size_type __size = size();
    if (__n > max_size() - __size)
      this->_M_throw_length_error();
    size_type __len = __size + (max)(__n, __size) + 1;
    if (__len > max_size() || __len < __size)
      __len = max_size(); // overflow
    return __len;
  }

  template <class _InputIter>
  void _M_range_initialize(_InputIter __f, _InputIter __l,
                           const input_iterator_tag &__tag) {
    this->_M_allocate_block();
    _M_construct_null(this->_M_Finish());
    _M_appendT(__f, __l, __tag);
  }

  template <class _ForwardIter>
  void _M_range_initialize(_ForwardIter __f, _ForwardIter __l,
                           const forward_iterator_tag &) {
    difference_type __n = _STLP_STD::distance(__f, __l);
    this->_M_allocate_block(__n + 1);
    this->_M_finish = uninitialized_copy(__f, __l, this->_M_Start());
    this->_M_terminate_string();
  }

  template <class _InputIter>
  void _M_range_initializeT(_InputIter __f, _InputIter __l) {
    _M_range_initialize(__f, __l, _STLP_ITERATOR_CATEGORY(__f, _InputIter));
  }

  template <class _Integer>
  void _M_initialize_dispatch(_Integer __n, _Integer __x, const __true_type& /*_Integral*/) {
    this->_M_allocate_block(__n + 1);
    this->_M_finish = _STLP_PRIV __uninitialized_fill_n(this->_M_Start(), __n, __x);
    this->_M_terminate_string();
  }

  template <class _InputIter>
  void _M_initialize_dispatch(_InputIter __f, _InputIter __l, const __false_type& /*_Integral*/) {
    _M_range_initializeT(__f, __l);
  }

public:
  _Self& operator=(const _Self& __s) {
    if (&__s != this)
      _M_assign(__s._M_Start(), __s._M_Finish());
    return *this;
  }

  _Self& operator=(const _CharT* __s) {
    _STLP_FIX_LITERAL_BUG(__s)
    return _M_assign(__s, __s + traits_type::length(__s));
  }

  _Self& operator=(_CharT __c)
  { return assign(__STATIC_CAST(size_type,1), __c); }

private:
  static _CharT _STLP_CALL _M_null()
  { return _STLP_DEFAULT_CONSTRUCTED(_CharT); }

_STLP_PRIVATE:                     // Helper functions used by constructors
                                   // and elsewhere.
  void _M_construct_null(_CharT* __p) const
  { _STLP_STD::_Construct(__p); }
  void _M_terminate_string()
  { _M_construct_null(this->_M_Finish()); }
  bool _M_inside(const _CharT* __s) const {
    _STLP_FIX_LITERAL_BUG(__s)
    return (__s >= this->_M_Start()) && (__s < this->_M_Finish());
  }

  void _M_range_initialize(const _CharT* __f, const _CharT* __l) {
    _STLP_FIX_LITERAL_BUG(__f) _STLP_FIX_LITERAL_BUG(__l)
    ptrdiff_t __n = __l - __f;
    this->_M_allocate_block(__n + 1);
    this->_M_finish = uninitialized_copy(__f, __l, this->_M_Start());
    _M_terminate_string();
  }

public:                         // Iterators.
  iterator begin()             { return this->_M_Start(); }
  iterator end()               { return this->_M_Finish(); }
  const_iterator begin() const { return this->_M_Start(); }
  const_iterator end()   const { return this->_M_Finish(); }

  reverse_iterator rbegin()
  { return reverse_iterator(this->_M_Finish()); }
  reverse_iterator rend()
  { return reverse_iterator(this->_M_Start()); }
  const_reverse_iterator rbegin() const
  { return const_reverse_iterator(this->_M_Finish()); }