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## Class template basic_string

boost::container::basic_string

## Synopsis

    // In header: <boost/container/string.hpp>

    template<typename CharT, typename Traits = std::char_traits<CharT>,
             typename A = std::allocator<CharT> >
    class basic_string {
    public:
      // types
      typedef A                                       allocator_type;
      typedef allocator_type                          stored_allocator_type;   // The stored allocator type.
      typedef CharT                                   value_type;              // The type of object, CharT, stored in the string.
      typedef Traits                                  traits_type;             // The second template parameter Traits.
      typedef allocator_traits_type::pointer          pointer;                 // Pointer to CharT.
      typedef allocator_traits_type::const_pointer    const_pointer;           // Const pointer to CharT.
      typedef allocator_traits_type::reference        reference;               // Reference to CharT.
      typedef allocator_traits_type::const_reference  const_reference;         // Const reference to CharT.
      typedef allocator_traits_type::size_type        size_type;               // An unsigned integral type.
      typedef allocator_traits_type::difference_type  difference_type;         // A signed integral type.
      typedef pointer                                 iterator;                // Iterator used to iterate through a string. It's a Random Access Iterator.
      typedef const_pointer                           const_iterator;          // Const iterator used to iterate through a string. It's a Random Access Iterator.
      typedef std::reverse_iterator< iterator >       reverse_iterator;        // Iterator used to iterate backwards through a string.
      typedef std::reverse_iterator< const_iterator > const_reverse_iterator;  // Const iterator used to iterate backwards through a string.

      // construct/copy/destruct
      basic_string();
      explicit basic_string(const allocator_type &);
      basic_string(const basic_string &);
      basic_string(basic_string &&);
      basic_string(const basic_string &, size_type, size_type = npos,
                   const allocator_type & = allocator_type());
      basic_string(const CharT *, size_type,
                   const allocator_type & = allocator_type());
      basic_string(const CharT *, const allocator_type & = allocator_type());
      basic_string(size_type, CharT, const allocator_type & = allocator_type());
      template<typename InputIterator>
        basic_string(InputIterator, InputIterator,
                     const allocator_type & = allocator_type());
      basic_string& operator=(const basic_string &);
      basic_string& operator=(basic_string &&);
      basic_string& operator=(const CharT *);
      basic_string& operator=(CharT);
      ~basic_string();

      // public member functions
      iterator begin();
      const_iterator begin() const;
      const_iterator cbegin() const;
      iterator end();
      const_iterator end() const;
      const_iterator cend() const;
      reverse_iterator rbegin();
      const_reverse_iterator rbegin() const;
      const_reverse_iterator crbegin() const;
      reverse_iterator rend();
      const_reverse_iterator rend() const;
      const_reverse_iterator crend() const;
      allocator_type get_allocator() const;
      const stored_allocator_type & get_stored_allocator() const;
      stored_allocator_type & get_stored_allocator();
      size_type size() const;
      size_type length() const;
      size_type max_size() const;
      void resize(size_type, CharT);
      void resize(size_type);
      void reserve(size_type);
      size_type capacity() const;
      void clear();
      void shrink_to_fit();
      bool empty() const;
      reference operator[](size_type);
      const_reference operator[](size_type) const;
      reference at(size_type);
      const_reference at(size_type) const;
      basic_string & operator+=(const basic_string &);
      basic_string & operator+=(const CharT *);
      basic_string & operator+=(CharT);
      basic_string & append(const basic_string &);
      basic_string & append(const basic_string &, size_type, size_type);
      basic_string & append(const CharT *, size_type);
      basic_string & append(const CharT *);
      basic_string & append(size_type, CharT);
      template<typename InputIter> basic_string & append(InputIter, InputIter);
      void push_back(CharT);
      basic_string & assign(const basic_string &);
      basic_string & assign(basic_string &&);
      basic_string & assign(const basic_string &, size_type, size_type);
      basic_string & assign(const CharT *, size_type);
      basic_string & assign(const CharT *);
      basic_string & assign(size_type, CharT);
      template<typename InputIter> basic_string & assign(InputIter, InputIter);
      basic_string & insert(size_type, const basic_string &);
      basic_string & insert(size_type, const basic_string &, size_type, size_type);
      basic_string & insert(size_type, const CharT *, size_type);
      basic_string & insert(size_type, const CharT *);
      basic_string & insert(size_type, size_type, CharT);
      iterator insert(const_iterator, CharT);
      void insert(const_iterator, size_type, CharT);
      template<typename InputIter>
        void insert(const_iterator, InputIter, InputIter);
      basic_string & erase(size_type = 0, size_type = npos);
      iterator erase(const_iterator);
      iterator erase(const_iterator, const_iterator);
      void pop_back();
      basic_string & replace(size_type, size_type, const basic_string &);
      basic_string &
      replace(size_type, size_type, const basic_string &, size_type, size_type);
      basic_string & replace(size_type, size_type, const CharT *, size_type);
      basic_string & replace(size_type, size_type, const CharT *);
      basic_string & replace(size_type, size_type, size_type, CharT);
      basic_string & replace(const_iterator, const_iterator, const basic_string &);
      basic_string &
      replace(const_iterator, const_iterator, const CharT *, size_type);
      basic_string & replace(const_iterator, const_iterator, const CharT *);
      basic_string & replace(const_iterator, const_iterator, size_type, CharT);
      template<typename InputIter>
        basic_string &
        replace(const_iterator, const_iterator, InputIter, InputIter);
      size_type copy(CharT *, size_type, size_type = 0) const;
      void swap(basic_string &);
      const CharT * c_str() const;
      const CharT * data() const;
      size_type find(const basic_string &, size_type = 0) const;
      size_type find(const CharT *, size_type, size_type) const;
      size_type find(const CharT *, size_type = 0) const;
      size_type find(CharT, size_type = 0) const;
      size_type rfind(const basic_string &, size_type = npos) const;
      size_type rfind(const CharT *, size_type, size_type) const;
      size_type rfind(const CharT *, size_type = npos) const;
      size_type rfind(CharT, size_type = npos) const;
      size_type find_first_of(const basic_string &, size_type = 0) const;
      size_type find_first_of(const CharT *, size_type, size_type) const;
      size_type find_first_of(const CharT *, size_type = 0) const;
      size_type find_first_of(CharT, size_type = 0) const;
      size_type find_last_of(const basic_string &, size_type = npos) const;
      size_type find_last_of(const CharT *, size_type, size_type) const;
      size_type find_last_of(const CharT *, size_type = npos) const;
      size_type find_last_of(CharT, size_type = npos) const;
      size_type find_first_not_of(const basic_string &, size_type = 0) const;
      size_type find_first_not_of(const CharT *, size_type, size_type) const;
      size_type find_first_not_of(const CharT *, size_type = 0) const;
      size_type find_first_not_of(CharT, size_type = 0) const;
      size_type find_last_not_of(const basic_string &, size_type = npos) const;
      size_type find_last_not_of(const CharT *, size_type, size_type) const;
      size_type find_last_not_of(const CharT *, size_type = npos) const;
      size_type find_last_not_of(CharT, size_type = npos) const;
      basic_string substr(size_type = 0, size_type = npos) const;
      int compare(const basic_string &) const;
      int compare(size_type, size_type, const basic_string &) const;
      int compare(size_type, size_type, const basic_string &, size_type,
                  size_type) const;
      int compare(const CharT *) const;
      int compare(size_type, size_type, const CharT *, size_type) const;
      int compare(size_type, size_type, const CharT *) const;

      // public data members
      static const size_type npos;  // The largest possible value of type size_type. That is, size_type(-1).
    };

## Description

The basic_string class represents a Sequence of characters. It contains all the usual operations of a Sequence, and, additionally, it contains standard string operations such as search and concatenation.

The basic_string class is parameterized by character type, and by that type's Character Traits.

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.

Some of basic_string's member functions use an unusual method of specifying positions and ranges. In addition to the conventional method using iterators, many of basic_string's member functions use a single value pos of type size_type to represent a position (in which case the position is begin() + pos, and many of basic_string's member functions use two values, pos and n, to represent a range. In that case pos is the beginning of the range and n is its size. That is, the range is [begin() + pos, begin() + pos + n).

Note that the C++ standard does not specify the complexity of basic_string operations. In this implementation, basic_string has performance characteristics very similar to those of vector: access to a single character is O(1), while copy and concatenation are O(N).

In this implementation, begin(), end(), rbegin(), rend(), operator[], c_str(), and data() do not invalidate iterators. In this implementation, iterators are only invalidated by member functions that explicitly change the string's contents.

### `basic_string` public types

1. typedef A allocator_type;

   The allocator type

### `basic_string` public construct/copy/destruct

1.     basic_string();

   Effects: Default constructs a `basic_string`.

   Throws: If allocator_type's default constructor throws.

2.     explicit basic_string(const allocator_type & a);

   Effects: Constructs a `basic_string` taking the allocator as parameter.

   Throws: If allocator_type's copy constructor throws.

3.     basic_string(const basic_string & s);

   Effects: Copy constructs a `basic_string`.

   Postcondition: x == *this.

   Throws: If allocator_type's default constructor or copy constructor throws.

4.     basic_string(basic_string && s);

   Effects: Move constructor. Moves mx's resources to *this.

   Throws: If allocator_type's copy constructor throws.

   Complexity: Constant.

5.     basic_string(const basic_string & s, size_type pos, size_type n = npos,
                    const allocator_type & a = allocator_type());

   Effects: Constructs a `basic_string` taking the allocator as parameter, and is initialized by a specific number of characters of the s string.

6.     basic_string(const CharT * s, size_type n,
                    const allocator_type & a = allocator_type());

   Effects: Constructs a `basic_string` taking the allocator as parameter, and is initialized by a specific number of characters of the s c-string.

7.     basic_string(const CharT * s, const allocator_type & a = allocator_type());

   Effects: Constructs a `basic_string` taking the allocator as parameter, and is initialized by the null-terminated s c-string.

8.     basic_string(size_type n, CharT c,
                    const allocator_type & a = allocator_type());

   Effects: Constructs a `basic_string` taking the allocator as parameter, and is initialized by n copies of c.

9.     template<typename InputIterator>
         basic_string(InputIterator f, InputIterator l,
                      const allocator_type & a = allocator_type());

   Effects: Constructs a `basic_string` taking the allocator as parameter, and a range of iterators.

10.     basic_string& operator=(const basic_string & x);

    Effects: Copy constructs a string.

    Postcondition: x == *this.

    Complexity: Linear to the elements x contains.

11.     basic_string& operator=(basic_string && x);

    Effects: Move constructor. Moves mx's resources to *this.

    Throws: If allocator_type's copy constructor throws.

    Complexity: Constant.

12.     basic_string& operator=(const CharT * s);

    Effects: Assignment from a null-terminated c-string.

13.     basic_string& operator=(CharT c);

    Effects: Assignment from character.

14.     ~basic_string();

    Effects: Destroys the `basic_string`. All used memory is deallocated.

    Throws: Nothing.

    Complexity: Constant.

### `basic_string` public member functions

1.     iterator begin();

   Effects: Returns an iterator to the first element contained in the vector.

   Throws: Nothing.

   Complexity: Constant.

2.     const_iterator begin() const;

   Effects: Returns a const_iterator to the first element contained in the vector.

   Throws: Nothing.

   Complexity: Constant.

3.     const_iterator cbegin() const;

   Effects: Returns a const_iterator to the first element contained in the vector.

   Throws: Nothing.

   Complexity: Constant.

4.     iterator end();

   Effects: Returns an iterator to the end of the vector.

   Throws: Nothing.

   Complexity: Constant.

5.     const_iterator end() const;

   Effects: Returns a const_iterator to the end of the vector.

   Throws: Nothing.

   Complexity: Constant.

6.     const_iterator cend() const;

   Effects: Returns a const_iterator to the end of the vector.

   Throws: Nothing.

   Complexity: Constant.

7.     reverse_iterator rbegin();

   Effects: Returns a reverse_iterator pointing to the beginning of the reversed vector.

   Throws: Nothing.

   Complexity: Constant.

8.     const_reverse_iterator rbegin() const;

   Effects: Returns a const_reverse_iterator pointing to the beginning of the reversed vector.

   Throws: Nothing.

   Complexity: Constant.

9.     const_reverse_iterator crbegin() const;

   Effects: Returns a const_reverse_iterator pointing to the beginning of the reversed vector.

   Throws: Nothing.

   Complexity: Constant.

10.     reverse_iterator rend();

    Effects: Returns a reverse_iterator pointing to the end of the reversed vector.

    Throws: Nothing.

    Complexity: Constant.

11.     const_reverse_iterator rend() const;

    Effects: Returns a const_reverse_iterator pointing to the end of the reversed vector.

    Throws: Nothing.

    Complexity: Constant.

12.     const_reverse_iterator crend() const;

    Effects: Returns a const_reverse_iterator pointing to the end of the reversed vector.

    Throws: Nothing.

    Complexity: Constant.

13.     allocator_type get_allocator() const;

    Effects: Returns a copy of the internal allocator.

    Throws: If allocator's copy constructor throws.

    Complexity: Constant.

14.     const stored_allocator_type & get_stored_allocator() const;

    Effects: Returns a reference to the internal allocator.

    Throws: Nothing

    Complexity: Constant.

    Note: Non-standard extension.

15.     stored_allocator_type & get_stored_allocator();

    Effects: Returns a reference to the internal allocator.

    Throws: Nothing

    Complexity: Constant.

    Note: Non-standard extension.

16.     size_type size() const;

    Effects: Returns the number of the elements contained in the vector.

    Throws: Nothing.

    Complexity: Constant.

17.     size_type length() const;

    Effects: Returns the number of the elements contained in the vector.

    Throws: Nothing.

    Complexity: Constant.

18.     size_type max_size() const;

    Effects: Returns the largest possible size of the vector.

    Throws: Nothing.

    Complexity: Constant.

19.     void resize(size_type n, CharT c);

    Effects: Inserts or erases elements at the end such that the size becomes n. New elements are copy constructed from x.

    Throws: If memory allocation throws

    Complexity: Linear to the difference between size() and new_size.

20.     void resize(size_type n);

    Effects: Inserts or erases elements at the end such that the size becomes n. New elements are default constructed.

    Throws: If memory allocation throws

    Complexity: Linear to the difference between size() and new_size.

21.     void reserve(size_type res_arg);

    Effects: If n is less than or equal to capacity(), this call has no effect. Otherwise, it is a request for allocation of additional memory. If the request is successful, then capacity() is greater than or equal to n; otherwise, capacity() is unchanged. In either case, size() is unchanged.

    Throws: If memory allocation allocation throws

22.     size_type capacity() const;

    Effects: Number of elements for which memory has been allocated. capacity() is always greater than or equal to size().

    Throws: Nothing.

    Complexity: Constant.

23.     void clear();

    Effects: Erases all the elements of the vector.

    Throws: Nothing.

    Complexity: Linear to the number of elements in the vector.

24.     void shrink_to_fit();

    Effects: Tries to deallocate the excess of memory created with previous allocations. The size of the string is unchanged

    Throws: Nothing

    Complexity: Linear to size().

25.     bool empty() const;

    Effects: Returns true if the vector contains no elements.

    Throws: Nothing.

    Complexity: Constant.

26.     reference operator[](size_type n);

    Requires: size() > n.

    Effects: Returns a reference to the nth element from the beginning of the container.

    Throws: Nothing.

    Complexity: Constant.

27.     const_reference operator[](size_type n) const;

    Requires: size() > n.

    Effects: Returns a const reference to the nth element from the beginning of the container.

    Throws: Nothing.

    Complexity: Constant.

28.     reference at(size_type n);

    Requires: size() > n.

    Effects: Returns a reference to the nth element from the beginning of the container.

    Throws: std::range_error if n >= size()

    Complexity: Constant.

29.     const_reference at(size_type n) const;

    Requires: size() > n.

    Effects: Returns a const reference to the nth element from the beginning of the container.

    Throws: std::range_error if n >= size()

    Complexity: Constant.

30.     basic_string & operator+=(const basic_string & s);

    Effects: Calls append(str.data, str.size()).

    Returns: *this

31.     basic_string & operator+=(const CharT * s);

    Effects: Calls append(s).

    Returns: *this

32.     basic_string & operator+=(CharT c);

    Effects: Calls append(1, c).

    Returns: *this

33.     basic_string & append(const basic_string & s);

    Effects: Calls append(str.data(), str.size()).

    Returns: *this

34.     basic_string & append(const basic_string & s, size_type pos, size_type n);

    Requires: pos <= str.size()

    Effects: Determines the effective length rlen of the string to append as the smaller of n and str.size() - pos and calls append(str.data() + pos, rlen).

    Throws: If memory allocation throws and out_of_range if pos > str.size()

    Returns: *this

35.     basic_string & append(const CharT * s, size_type n);

    Requires: s points to an array of at least n elements of CharT.

    Effects: The function replaces the string controlled by *this with a string of length size() + n whose irst size() elements are a copy of the original string controlled by *this and whose remaining elements are a copy of the initial n elements of s.

    Throws: If memory allocation throws length_error if size() + n > max_size().

    Returns: *this

36.     basic_string & append(const CharT * s);

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Effects: Calls append(s, traits::length(s)).

    Returns: *this

37.     basic_string & append(size_type n, CharT c);

    Effects: Equivalent to append(basic_string(n, c)).

    Returns: *this

38.     template<typename InputIter>
          basic_string & append(InputIter first, InputIter last);

    Requires: [first,last) is a valid range.

    Effects: Equivalent to append(basic_string(first, last)).

    Returns: *this

39.     void push_back(CharT c);

    Effects: Equivalent to append(static_cast<size_type>(1), c).

40.     basic_string & assign(const basic_string & s);

    Effects: Equivalent to assign(str, 0, npos).

    Returns: *this

41.     basic_string & assign(basic_string && ms);

    Effects: The function replaces the string controlled by *this with a string of length str.size() whose elements are a copy of the string controlled by str. Leaves str in a valid but unspecified state.

    Throws: Nothing

    Returns: *this

42.     basic_string & assign(const basic_string & s, size_type pos, size_type n);

    Requires: pos <= str.size()

    Effects: Determines the effective length rlen of the string to assign as the smaller of n and str.size() - pos and calls assign(str.data() + pos rlen).

    Throws: If memory allocation throws or out_of_range if pos > str.size().

    Returns: *this

43.     basic_string & assign(const CharT * s, size_type n);

    Requires: s points to an array of at least n elements of CharT.

    Effects: Replaces the string controlled by *this with a string of length n whose elements are a copy of those pointed to by s.

    Throws: If memory allocation throws or length_error if n > max_size().

    Returns: *this

44.     basic_string & assign(const CharT * s);

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Effects: Calls assign(s, traits::length(s)).

    Returns: *this

45.     basic_string & assign(size_type n, CharT c);

    Effects: Equivalent to assign(basic_string(n, c)).

    Returns: *this

46.     template<typename InputIter>
          basic_string & assign(InputIter first, InputIter last);

    Effects: Equivalent to assign(basic_string(first, last)).

    Returns: *this

47.     basic_string & insert(size_type pos, const basic_string & s);

    Requires: pos <= size().

    Effects: Calls insert(pos, str.data(), str.size()).

    Throws: If memory allocation throws or out_of_range if pos > size().

    Returns: *this

48.     basic_string &
        insert(size_type pos1, const basic_string & s, size_type pos2, size_type n);

    Requires: pos1 <= size() and pos2 <= str.size()

    Effects: Determines the effective length rlen of the string to insert as the smaller of n and str.size() - pos2 and calls insert(pos1, str.data() + pos2, rlen).

    Throws: If memory allocation throws or out_of_range if pos1 > size() or pos2 > str.size().

    Returns: *this

49.     basic_string & insert(size_type pos, const CharT * s, size_type n);

    Requires: s points to an array of at least n elements of CharT and pos <= size().

    Effects: Replaces the string controlled by *this with a string of length size() + n whose first pos elements are a copy of the initial elements of the original string controlled by *this and whose next n elements are a copy of the elements in s and whose remaining elements are a copy of the remaining elements of the original string controlled by *this.

    Throws: If memory allocation throws, out_of_range if pos > size() or length_error if size() + n > max_size().

    Returns: *this

50.     basic_string & insert(size_type pos, const CharT * s);

    Requires: pos <= size() and s points to an array of at least traits::length(s) + 1 elements of CharT

    Effects: Calls insert(pos, s, traits::length(s)).

    Throws: If memory allocation throws, out_of_range if pos > size() length_error if size() > max_size() - Traits::length(s)

    Returns: *this

51.     basic_string & insert(size_type pos, size_type n, CharT c);

    Effects: Equivalent to insert(pos, basic_string(n, c)).

    Throws: If memory allocation throws, out_of_range if pos > size() length_error if size() > max_size() - n

    Returns: *this

52.     iterator insert(const_iterator p, CharT c);

    Requires: p is a valid iterator on *this.

    Effects: inserts a copy of c before the character referred to by p.

    Returns: An iterator which refers to the copy of the inserted character.

53.     void insert(const_iterator p, size_type n, CharT c);

    Requires: p is a valid iterator on *this.

    Effects: Inserts n copies of c before the character referred to by p.

    Returns: An iterator which refers to the copy of the first inserted character, or p if n == 0.

54.     template<typename InputIter>
          void insert(const_iterator p, InputIter first, InputIter last);

    Requires: p is a valid iterator on *this. [first,last) is a valid range.

    Effects: Equivalent to insert(p - begin(), basic_string(first, last)).

    Returns: An iterator which refers to the copy of the first inserted character, or p if first == last.

55.     basic_string & erase(size_type pos = 0, size_type n = npos);

    Requires: pos <= size()

    Effects: Determines the effective length xlen of the string to be removed as the smaller of n and size() - pos. The function then replaces the string controlled by *this with a string of length size() - xlen whose first pos elements are a copy of the initial elements of the original string controlled by *this, and whose remaining elements are a copy of the elements of the original string controlled by *this beginning at position pos + xlen.

    Throws: out_of_range if pos > size().

    Returns: *this

56.     iterator erase(const_iterator p);

    Effects: Removes the character referred to by p.

    Throws: Nothing

    Returns: An iterator which points to the element immediately following p prior to the element being erased. If no such element exists, end() is returned.

57.     iterator erase(const_iterator first, const_iterator last);

    Requires: first and last are valid iterators on *this, defining a range [first,last).

    Effects: Removes the characters in the range [first,last).

    Throws: Nothing

    Returns: An iterator which points to the element pointed to by last prior to the other elements being erased. If no such element exists, end() is returned.

58.     void pop_back();

    Requires: !empty()

    Throws: Nothing

    Effects: Equivalent to erase(size() - 1, 1).

59.     basic_string & replace(size_type pos1, size_type n1, const basic_string & str);

    Requires: pos1 <= size().

    Effects: Calls replace(pos1, n1, str.data(), str.size()).

    Throws: if memory allocation throws or out_of_range if pos1 > size().

    Returns: *this

60.     basic_string &
        replace(size_type pos1, size_type n1, const basic_string & str,
                size_type pos2, size_type n2);

    Requires: pos1 <= size() and pos2 <= str.size().

    Effects: Determines the effective length rlen of the string to be inserted as the smaller of n2 and str.size() - pos2 and calls replace(pos1, n1, str.data() + pos2, rlen).

    Throws: if memory allocation throws, out_of_range if pos1 > size() or pos2 > str.size().

    Returns: *this

61.     basic_string &
        replace(size_type pos1, size_type n1, const CharT * s, size_type n2);

    Requires: pos1 <= size() and s points to an array of at least n2 elements of CharT.

    Effects: Determines the effective length xlen of the string to be removed as the smaller of n1 and size() - pos1. If size() - xlen >= max_size() - n2 throws length_error. Otherwise, the function replaces the string controlled by *this with a string of length size() - xlen + n2 whose first pos1 elements are a copy of the initial elements of the original string controlled by *this, whose next n2 elements are a copy of the initial n2 elements of s, and whose remaining elements are a copy of the elements of the original string controlled by *this beginning at position pos + xlen.

    Throws: if memory allocation throws, out_of_range if pos1 > size() or length_error if the length of the resulting string would exceed max_size()

    Returns: *this

62.     basic_string & replace(size_type pos, size_type n1, const CharT * s);

    Requires: pos1 <= size() and s points to an array of at least n2 elements of CharT.

    Effects: Determines the effective length xlen of the string to be removed as the smaller of n1 and size() - pos1. If size() - xlen >= max_size() - n2 throws length_error. Otherwise, the function replaces the string controlled by *this with a string of length size() - xlen + n2 whose first pos1 elements are a copy of the initial elements of the original string controlled by *this, whose next n2 elements are a copy of the initial n2 elements of s, and whose remaining elements are a copy of the elements of the original string controlled by *this beginning at position pos + xlen.

    Throws: if memory allocation throws, out_of_range if pos1 > size() or length_error if the length of the resulting string would exceed max_size()

    Returns: *this

63.     basic_string & replace(size_type pos1, size_type n1, size_type n2, CharT c);

    Requires: pos1 <= size().

    Effects: Equivalent to replace(pos1, n1, basic_string(n2, c)).

    Throws: if memory allocation throws, out_of_range if pos1 > size() or length_error if the length of the resulting string would exceed max_size()

    Returns: *this

64.     basic_string &
        replace(const_iterator i1, const_iterator i2, const basic_string & str);

    Requires: [begin(),i1) and [i1,i2) are valid ranges.

    Effects: Calls replace(i1 - begin(), i2 - i1, str).

    Throws: if memory allocation throws

    Returns: *this

65.     basic_string &
        replace(const_iterator i1, const_iterator i2, const CharT * s, size_type n);

    Requires: [begin(),i1) and [i1,i2) are valid ranges and s points to an array of at least n elements

    Effects: Calls replace(i1 - begin(), i2 - i1, s, n).

    Throws: if memory allocation throws

    Returns: *this

66.     basic_string & replace(const_iterator i1, const_iterator i2, const CharT * s);

    Requires: [begin(),i1) and [i1,i2) are valid ranges and s points to an array of at least traits::length(s) + 1 elements of CharT.

    Effects: Calls replace(i1 - begin(), i2 - i1, s, traits::length(s)).

    Throws: if memory allocation throws

    Returns: *this

67.     basic_string &
        replace(const_iterator i1, const_iterator i2, size_type n, CharT c);

    Requires: [begin(),i1) and [i1,i2) are valid ranges.

    Effects: Calls replace(i1 - begin(), i2 - i1, basic_string(n, c)).

    Throws: if memory allocation throws

    Returns: *this

68.     template<typename InputIter>
          basic_string &
          replace(const_iterator i1, const_iterator i2, InputIter j1, InputIter j2);

    Requires: [begin(),i1), [i1,i2) and [j1,j2) are valid ranges.

    Effects: Calls replace(i1 - begin(), i2 - i1, basic_string(j1, j2)).

    Throws: if memory allocation throws

    Returns: *this

69.     size_type copy(CharT * s, size_type n, size_type pos = 0) const;

    Requires: pos <= size()

    Effects: Determines the effective length rlen of the string to copy as the smaller of n and size() - pos. s shall designate an array of at least rlen elements. The function then replaces the string designated by s with a string of length rlen whose elements are a copy of the string controlled by *this beginning at position pos. The function does not append a null object to the string designated by s.

    Throws: if memory allocation throws, out_of_range if pos > size().

    Returns: rlen

70.     void swap(basic_string & x);

    Effects: *this contains the same sequence of characters that was in s, s contains the same sequence of characters that was in *this.

    Throws: Nothing

71.     const CharT * c_str() const;

    Requires: The program shall not alter any of the values stored in the character array.

    Returns: A pointer p such that p + i == &operator[](i) for each i in [0,size()].

    Complexity: constant time.

72.     const CharT * data() const;

    Requires: The program shall not alter any of the values stored in the character array.

    Returns: A pointer p such that p + i == &operator[](i) for each i in [0,size()].

    Complexity: constant time.

73.     size_type find(const basic_string & s, size_type pos = 0) const;

    Effects: Determines the lowest position xpos, if possible, such that both of the following conditions obtain: 19 pos <= xpos and xpos + str.size() <= size(); 2) traits::eq(at(xpos+I), str.at(I)) for all elements I of the string controlled by str.

    Throws: Nothing

    Returns: xpos if the function can determine such a value for xpos. Otherwise, returns npos.

74.     size_type find(const CharT * s, size_type pos, size_type n) const;

    Requires: s points to an array of at least n elements of CharT.

    Throws: Nothing

    Returns: find(basic_string<CharT,traits,Allocator>(s,n),pos).

75.     size_type find(const CharT * s, size_type pos = 0) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find(basic_string(s), pos).

76.     size_type find(CharT c, size_type pos = 0) const;

    Throws: Nothing

    Returns: find(basic_string<CharT,traits,Allocator>(1,c), pos).

77.     size_type rfind(const basic_string & str, size_type pos = npos) const;

    Effects: Determines the highest position xpos, if possible, such that both of the following conditions obtain: a) xpos <= pos and xpos + str.size() <= size(); b) traits::eq(at(xpos+I), str.at(I)) for all elements I of the string controlled by str.

    Throws: Nothing

    Returns: xpos if the function can determine such a value for xpos. Otherwise, returns npos.

78.     size_type rfind(const CharT * s, size_type pos, size_type n) const;

    Requires: s points to an array of at least n elements of CharT.

    Throws: Nothing

    Returns: rfind(basic_string(s, n), pos).

79.     size_type rfind(const CharT * s, size_type pos = npos) const;

    Requires: pos <= size() and s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: rfind(basic_string(s), pos).

80.     size_type rfind(CharT c, size_type pos = npos) const;

    Throws: Nothing

    Returns: rfind(basic_string<CharT,traits,Allocator>(1,c),pos).

81.     size_type find_first_of(const basic_string & s, size_type pos = 0) const;

    Effects: Determines the lowest position xpos, if possible, such that both of the following conditions obtain: a) pos <= xpos and xpos < size(); b) traits::eq(at(xpos), str.at(I)) for some element I of the string controlled by str.

    Throws: Nothing

    Returns: xpos if the function can determine such a value for xpos. Otherwise, returns npos.

82.     size_type find_first_of(const CharT * s, size_type pos, size_type n) const;

    Requires: s points to an array of at least n elements of CharT.

    Throws: Nothing

    Returns: find_first_of(basic_string(s, n), pos).

83.     size_type find_first_of(const CharT * s, size_type pos = 0) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find_first_of(basic_string(s), pos).

84.     size_type find_first_of(CharT c, size_type pos = 0) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find_first_of(basic_string<CharT,traits,Allocator>(1,c), pos).

85.     size_type find_last_of(const basic_string & str, size_type pos = npos) const;

    Effects: Determines the highest position xpos, if possible, such that both of the following conditions obtain: a) xpos <= pos and xpos < size(); b) traits::eq(at(xpos), str.at(I)) for some element I of the string controlled by str.

    Throws: Nothing

    Returns: xpos if the function can determine such a value for xpos. Otherwise, returns npos.

86.     size_type find_last_of(const CharT * s, size_type pos, size_type n) const;

    Requires: s points to an array of at least n elements of CharT.

    Throws: Nothing

    Returns: find_last_of(basic_string(s, n), pos).

87.     size_type find_last_of(const CharT * s, size_type pos = npos) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find_last_of(basic_string<CharT,traits,Allocator>(1,c),pos).

88.     size_type find_last_of(CharT c, size_type pos = npos) const;

    Throws: Nothing

    Returns: find_last_of(basic_string(s), pos).

89.     size_type find_first_not_of(const basic_string & str, size_type pos = 0) const;

    Effects: Determines the lowest position xpos, if possible, such that both of the following conditions obtain: a) pos <= xpos and xpos < size(); b) traits::eq(at(xpos), str.at(I)) for no element I of the string controlled by str.

    Throws: Nothing

    Returns: xpos if the function can determine such a value for xpos. Otherwise, returns npos.

90.     size_type find_first_not_of(const CharT * s, size_type pos, size_type n) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find_first_not_of(basic_string(s, n), pos).

91.     size_type find_first_not_of(const CharT * s, size_type pos = 0) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find_first_not_of(basic_string(s), pos).

92.     size_type find_first_not_of(CharT c, size_type pos = 0) const;

    Throws: Nothing

    Returns: find_first_not_of(basic_string(1, c), pos).

93.     size_type find_last_not_of(const basic_string & str, size_type pos = npos) const;

    Effects: Determines the highest position xpos, if possible, such that both of the following conditions obtain: a) xpos <= pos and xpos < size(); b) traits::eq(at(xpos), str.at(I)) for no element I of the string controlled by str.

    Throws: Nothing

    Returns: xpos if the function can determine such a value for xpos. Otherwise, returns npos.

94.     size_type find_last_not_of(const CharT * s, size_type pos, size_type n) const;

    Requires: s points to an array of at least n elements of CharT.

    Throws: Nothing

    Returns: find_last_not_of(basic_string(s, n), pos).

95.     size_type find_last_not_of(const CharT * s, size_type pos = npos) const;

    Requires: s points to an array of at least traits::length(s) + 1 elements of CharT.

    Throws: Nothing

    Returns: find_last_not_of(basic_string(s), pos).

96.     size_type find_last_not_of(CharT c, size_type pos = npos) const;

    Throws: Nothing

    Returns: find_last_not_of(basic_string(1, c), pos).

97.     basic_string substr(size_type pos = 0, size_type n = npos) const;

    Requires: Requires: pos <= size()

    Effects: Determines the effective length rlen of the string to copy as the smaller of n and size() - pos.

    Throws: If memory allocation throws or out_of_range if pos > size().

    Returns: basic_string<CharT,traits,Allocator>(data()+pos,rlen).

98.     int compare(const basic_string & str) const;

    Effects: Determines the effective length rlen of the string to copy as the smaller of size() and str.size(). The function then compares the two strings by calling traits::compare(data(), str.data(), rlen).

    Throws: Nothing

    Returns: The nonzero result if the result of the comparison is nonzero. Otherwise, returns a value < 0 if size() < str.size(), a 0 value if size() == str.size(), and value > 0 if size() > str.size()

99.     int compare(size_type pos1, size_type n1, const basic_string & str) const;

    Requires: pos1 <= size()

    Effects: Determines the effective length rlen of the string to copy as the smaller of

    Throws: out_of_range if pos1 > size()

    Returns:basic_string(*this,pos1,n1).compare(str).

100.     int compare(size_type pos1, size_type n1, const basic_string & str,
                     size_type pos2, size_type n2) const;

     Requires: pos1 <= size() and pos2 <= str.size()

     Effects: Determines the effective length rlen of the string to copy as the smaller of

     Throws: out_of_range if pos1 > size() or pos2 > str.size()

     Returns: basic_string(*this, pos1, n1).compare(basic_string(str, pos2, n2)).

101.     int compare(const CharT * s) const;

     Throws: Nothing

     Returns: compare(basic_string(s)).

102.     int compare(size_type pos1, size_type n1, const CharT * s, size_type n2) const;

     Requires: pos1 > size() and s points to an array of at least n2 elements of CharT.

     Throws: out_of_range if pos1 > size()

     Returns: basic_string(*this, pos, n1).compare(basic_string(s, n2)).

103.     int compare(size_type pos1, size_type n1, const CharT * s) const;

     Requires: pos1 > size() and s points to an array of at least traits::length(s) + 1 elements of CharT.

     Throws: out_of_range if pos1 > size()

     Returns: basic_string(*this, pos, n1).compare(basic_string(s, n2)).