basic_string.h

openRisc2000编译链接器等,用于i386 cygwin

       */
      explicit
      basic_string(const _Alloc& __a);

      // NB: per LWG issue 42, semantics different from IS:
      /**
       *  @brief  Construct string with copy of value of @a str.
       *  @param  str  Source string.
       */
      basic_string(const basic_string& __str);
      /**
       *  @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).
       */
      basic_string(const basic_string& __str, size_type __pos,
		   size_type __n = npos);
      /**
       *  @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.
       */
      basic_string(const basic_string& __str, size_type __pos,
		   size_type __n, const _Alloc& __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: s must have at least n characters, '\0' has no special
       *  meaning.
       */
      basic_string(const _CharT* __s, size_type __n,
		   const _Alloc& __a = _Alloc());
      /**
       *  @brief  Construct string as copy of a C string.
       *  @param  s  Source C string.
       *  @param  a  Allocator to use (default is default allocator).
       */
      basic_string(const _CharT* __s, const _Alloc& __a = _Alloc());
      /**
       *  @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).
       */
      basic_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc());

      /**
       *  @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>
        basic_string(_InputIterator __beg, _InputIterator __end,
		     const _Alloc& __a = _Alloc());

      /**
       *  @brief  Destroy the string instance.
       */
      ~basic_string()
      { _M_rep()->_M_dispose(this->get_allocator()); }

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

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

      /**
       *  @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.
       */
      basic_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()
      {
	_M_leak();
	return iterator(_M_data());
      }

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

      /**
       *  Returns a read/write iterator that points one past the last
       *  character in the %string.  Unshares the string.
       */
      iterator
      end()
      {
	_M_leak();
	return iterator(_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(_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()); }

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

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

      /// Returns the size() of the largest possible %string.
      size_type
      max_size() const { return _Rep::_S_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 _M_rep()->_M_capacity; }

      /**
       *  @brief  Attempt to preallocate enough memory for specified number of
       *          characters.
       *  @param  n  Number of characters required.
       *  @throw  std::length_error  If @a n 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);

      /**
       *  Erases the string, making it empty.
       */
      void
      clear() { _M_mutate(0, this->size(), 0); }

      /**
       *  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  n  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 <= size());
	return _M_data()[__pos];
      }

      /**
       *  @brief  Subscript access to the data contained in the %string.
       *  @param  n  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)
      {
	_GLIBCXX_DEBUG_ASSERT(__pos < size());
	_M_leak();
	return _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())
	  __throw_out_of_range(__N("basic_string::at"));
	return _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 >= size())
	  __throw_out_of_range(__N("basic_string::at"));
	_M_leak();
	return _M_data()[__n];
      }

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

      /**
       *  @brief  Append a C string.
       *  @param s  The C string to append.
       *  @return  Reference to this string.
       */
      basic_string&