______________________________________________________________________

  Annex D (normative)

  Compatibility features                                [depr]

  ______________________________________________________________________

1 This Clause describes features of the C++ Standard that are  specified
  for compatibility with existing implementations.

2 These  are deprecated features, where deprecated is defined as: Norma­
  tive for the current edition of the Standard, but not guaranteed to be
  part of the Standard in future revisions.

  D.1  Postfix increment operator                       [depr.post.incr]

1 The  use  of  an  operand of type bool with the postfix ++ operator is
  deprecated (see _expr.post.incr_).

  D.2  static keyword                                      [depr.static]

1 The use of the static keyword is deprecated when declaring objects  in
  namespace scope (see _basic.scope.namespace_).

  D.3  Access declarations                             [depr.access.dcl]

1 Access declarations are deprecated (see _class.access.dcl_).

2
  D.4  Standard C library headers                       [depr.c.headers]

1 For  compatibility  with  the  Standard  C  library,  the C++ Standard
  library provides the 18 C headers, as shown in Table 1:

                            Table 1--C Headers

      <assert.h>   <iso646.h>   <setjmp.h>   <stdio.h>    <wchar.h>
      <ctype.h>    <limits.h>   <signal.h>   <stdlib.h>   <wctype.h>
      <errno.h>    <locale.h>   <stdarg.h>   <string.h>
      <float.h>    <math.h>     <stddef.h>   <time.h>

2 Each C header, whose name has the form name.h, behaves as if each name
  placed  in  the  Standard library namespace by the corresponding cname
  header is also placed within the namespace scope of the namespace  std
  and is followed by an explicit using-declaration (_namespace.udecl_)

3 [Example:  The  header <cstdlib> provides its declarations and defini­
  tions within the namespace std.  The  header  <stdlib.h>  makes  these
  available in the global name space, much as in the C Standard.   --end
  example]

4 The C++ headers

  --<iostream.h> and

  --<strstream.h>
    are similarly available.

  D.5  Old iostreams members                          [depr.ios.members]

1 The following member names are  in  addition  to  names  specified  in
  Clause _lib.iostreams_:
  namespace std {
    class ios_base {
    public:
      typedef T1  io_state;
      typedef T2 open_mode;
      typedef T3  seek_dir;
      typedef OFF_T  streamoff;
      typedef OFF_T  streampos;
      // remainder unchanged
    };
  }

2 The  type io_state is a synonym for an integer type (indicated here as
  T1) that permits certain member functions to overload others on param­
  eters of type iostate and provide the same behavior.

3 The type open_mode is a synonym for an integer type (indicated here as
  T2) that permits certain member functions to overload others on param­
  eters of type openmode and provide the same behavior.

4 The  type seek_dir is a synonym for an integer type (indicated here as
  T3) that permits certain member functions to overload others on param­
  eters of type iostate and provide the same behavior.

5 The  type  streamoff  is an implementation-defined type that satisfies
  the requirements of type OFF_T (_lib.iostreams.off.t_).

6 The type streampos is an implementation-defined  type  that  satisfies
  the requirements of type POS_T (_lib.iostreams.pos.t_).

7 An  implementation  may  provide the following additional member func­
  tion,    which    has    the    effect     of     calling     sbumpc()
  (_lib.streambuf.pub.get_):

  namespace std {
    template<class charT, class traits = ios_traits<charT> >
    class basic_streambuf {
    public:
      void stossc();
      // remainder unchanged
    };
  }

8 An  implementation  may  provide  the  following member functions that
  overload signatures specified in Clause _lib.iostreams_:
  namespace std {
    template<class charT, class Traits> class basic_ios {
    public:
      void clear(io_state state);
      void setstate(io_state state);
      // remainder unchanged
    };
    class ios_base {
    public:
      void exceptions(io_state);
      // remainder unchanged
    };
    template<class charT, class traits = ios_traits<charT> >
    class basic_streambuf {
    public:
      pos_type pubseekoff(off_type off, ios_base::seek_dir way,
                ios_base::open_mode which = ios_base::in | ios_base::out);
      pos_type pubseekpos(pos_type sp,
                ios_base::open_mode which = ios_base::in | ios_base::out);
      // remainder unchanged
    };
    template <class charT, class traits = ios_traits<charT> >
    class basic_filebuf : public basic_streambuf<charT,traits> {
    public:
      basic_filebuf<charT,traits>* open(const char* s, ios_base::open_mode mode);
      // remainder unchanged
    };
    template <class charT, class traits = file_traits<charT> >
    class basic_ifstream : public basic_istream<charT,traits> {
    public:
      void open(const char* s, open_mode mode = in);
      // remainder unchanged
    };
    template <class charT, class traits = file_traits<charT> >
    class basic_ofstream : public basic_ostream<charT,traits> {
    public:
      void open(const char* s, ios_base::open_mode mode = out | trunc);
      // remainder unchanged
    };
  }

9 The effects of these functions is to  call  the  corresponding  member
  function specified in Clause _lib.iostreams_.

  +-------                 BEGIN BOX 1                -------+
  ISSUE:  Were  these intended to be allowed in the template, or only in
  the specializations for char?
  +-------                  END BOX 1                 -------+

  D.6  char* streams                               [depr.str.strstreams]

1 The header <strstream> (and, as per  _depr.c.headers_,  <strstream.h>)
  defines three types that associate stream buffers with character array
  objects and assist reading and writing such objects.

  D.6.1  Class strstreambuf                          [depr.strstreambuf]
  namespace std {
    class strstreambuf : public basic_streambuf<char> {
    public:
      explicit strstreambuf(streamsize alsize_arg = 0);
      strstreambuf(void* (*palloc_arg)(size_t), void (*pfree_arg)(void*));
      strstreambuf(char* gnext_arg, streamsize n, char* pbeg_arg = 0);
      strstreambuf(const char* gnext_arg, streamsize n);
      strstreambuf(signed char* gnext_arg, streamsize n,
                   signed char* pbeg_arg = 0);
      strstreambuf(const signed char* gnext_arg, streamsize n);
      strstreambuf(unsigned char* gnext_arg, streamsize n,
                   unsigned char* pbeg_arg = 0);
      strstreambuf(const unsigned char* gnext_arg, streamsize n);
      virtual ~strstreambuf();
      void  freeze(bool freezefl = 1);
      char* str();
      int   pcount();
    protected:
      virtual int_type overflow (int_type c = EOF);
      virtual int_type pbackfail(int_type c = EOF);
      virtual int_type underflow();
      virtual pos_type seekoff(off_type off, ios_base::seekdir way,
                               ios_base::openmode which
                                = ios_base::in | ios_base::out);
      virtual pos_type seekpos(pos_type sp, ios_base::openmode which
                                = ios_base::in | ios_base::out);
      virtual streambuf<char>* setbuf(char* s, streamsize n);

    private:
  //  typedef T1 strstate;                exposition only
  //  static const strstate allocated;    exposition only
  //  static const strstate constant;     exposition only
  //  static const strstate dynamic;      exposition only
  //  static const strstate frozen;       exposition only
  //  strstate strmode;                   exposition only
  //  streamsize alsize;                  exposition only
  //  void* (*palloc)(size_t);            exposition only
  //  void (*pfree)(void*);               exposition only
    };
  }

1 The class strstreambuf associates the input sequence, and possibly the
  output  sequence,  with  an object of some character array type, whose
  elements  store  arbitrary  values.   The  array  object  has  several
  attributes.

2 [Note:  For  the sake of exposition, these are represented as elements
  of a bitmask type (indicated here as T1) called  strstate.   The  ele­
  ments are:

  --allocated,  set  when a dynamic array object has been allocated, and
    hence should be freed by the destructor for the strstreambuf object;

  --constant,  set when the array object has const elements, so the out­
    put sequence cannot be written;

  --dynamic, set when the array object is allocated (or reallocated)  as
    necessary to hold a character sequence that can change in length;

  --frozen, set when the program has requested that the array object not
    be altered, reallocated, or freed.   --end note]

3 [Note: For the sake of exposition, the maintained  data  is  presented
  here as:

  --strstate strmode, the attributes of the array object associated with
    the strstreambuf object;

  --int alsize, the suggested minimum size for a dynamic array object;

  --void* (*palloc)(size_t), points to the function to call to  allocate
    a dynamic array object;

  --void  (*pfree)(void*),  points  to  the  function  to call to free a
    dynamic array object.   --end note]

4 Each object of class strstreambuf has a seekable  area,  delimited  by
  the  pointers  seeklow  and seekhigh.  If gnext is a null pointer, the
  seekable area  is  undefined.   Otherwise,  seeklow  equals  gbeg  and
  seekhigh is either pend, if pend is not a null pointer, or gend.

  D.6.1.1  strstreambuf constructors            [depr.strstreambuf.cons]

  explicit strstreambuf(streamsize alsize_arg = 0);

  Effects:
    Constructs  an  object  of class strstreambuf, initializing the base
    class with streambuf().
    The postconditions of this function are indicated in Table 2:

                 Table 2--strstreambuf(streamsize) effects

                         +-------------------------+
                         |Element       Value      |
                         +-------------------------+
                         |strmode   dynamic        |
                         |alsize    alsize_arg     |
                         |palloc    a null pointer |
                         |pfree     a null pointer |
                         +-------------------------+

  strstreambuf(void* (*palloc_arg)(size_t), void (*pfree_arg)(void*));

  Effects:
    Constructs an object of class strstreambuf,  initializing  the  base
    class with streambuf().
    The postconditions of this function are indicated in Table 3:

      Table 3--strstreambuf(void* (*)(size_t),void (*)(void*) effects

                      +-------------------------------+
                      |Element          Value         |
                      +-------------------------------+
                      |strmode   dynamic              |
                      |alsize    an unspecified value |
                      |palloc    palloc_arg           |
                      |pfree     pfree_arg            |
                      +-------------------------------+

  strstreambuf(char* gnext_arg, streamsize n, char *pbeg_arg = 0);
  strstreambuf(signed char* gnext_arg, streamsize n,
                                             signed char *pbeg_arg = 0);
  strstreambuf(unsigned char* gnext_arg, streamsize n,
                                             unsigned char *pbeg_arg = 0);

  Effects:
    Constructs  an  object  of class strstreambuf, initializing the base

    class with streambuf().
    The postconditions of this function are indicated in Table 4:

          Table 4--strstreambuf(charT*,streamsize,charT*) effects

                      +-------------------------------+
                      |Element          Value         |
                      +-------------------------------+
                      |strmode   0                    |
                      |alsize    an unspecified value |
                      |palloc    a null pointer       |
                      |pfree     a null pointer       |
                      +-------------------------------+

1 gnext_arg shall point to the first element of an  array  object  whose
  number of elements N is determined as follows:

  --If n > 0, N is n.

  --If n == 0, N is ::strlen(gnext_arg).

  --If n < 0, N is INT_MAX.1)

2 If pbeg_arg is a null pointer, the function executes:
    setg(gnext_arg, gnext_arg, gnext_arg + N);

3 Otherwise, the function executes:
    setg(gnext_arg, gnext_arg, pbeg_arg);
    setp(pbeg_arg,  pbeg_arg + N);

  strstreambuf(const char* gnext_arg, streamsize n);
  strstreambuf(const signed char* gnext_arg, streamsize n);
  strstreambuf(const unsigned char* gnext_arg, streamsize n);

  Effects:
    Behaves  the  same  as strstreambuf((char*)gnext_arg,n), except that
    the constructor also sets constant in strmode.

  virtual ~strstreambuf();

  Effects:
    Destroys an object of class strstreambuf.  The  function  frees  the
    dynamically  allocated array object only if strmode & allocated != 0
    and strmode & frozen == 0.   (Subclause  _lib.strstreambuf.virtuals_
  _________________________
  1)   The   function  signature  strlen(const  char*)  is  declared  in
  <cstring>.   (_lib.c.strings_).   The  macro  INT_MAX  is  defined  in
  <climits> (_lib.support.limits_).

    describes how a dynamically allocated array object is freed.)

  D.6.1.2  Member functions                  [depr.strstreambuf.members]

  void freeze(bool freezefl = 1);

  Effects:
    If  strmode  &  dynamic is non-zero, alters the freeze status of the
    dynamic array object as follows:

  --If freezefl is false, the function sets frozen in strmode.

  --Otherwise, it clears frozen in strmode.

  char* str();

  Effects:
    Calls freeze(), then returns the beginning  pointer  for  the  input
    sequence, gbeg.
  Notes:
    The return value can be a null pointer.

  int pcount() const;

  Effects:
    If  the  next  pointer  for  the  output  sequence, pnext, is a null
    pointer, returns zero.  Otherwise,  returns  the  current  effective
    length  of  the array object as the next pointer minus the beginning
    pointer for the output sequence, pnext - pbeg.

  D.6.1.3  strstreambuf overridden          [depr.strstreambuf.virtuals]
       virtual functions

  int_type overflow(int_type c = EOF);

  +-------                 BEGIN BOX 2                -------+
  This needs to be rewritten in terms of consuming characters to be con­
  sistent with the revised protocol for overflow.
  +-------                  END BOX 2                 -------+

  Effects:
    Appends the character designated by c to  the  output  sequence,  if
    possible, in one of two ways:

  --If  c  != EOF and if either the output sequence has a write position
    available or the function  makes  a  write  position  available  (as
    described below), assigns c to *pnext++.
    Returns (unsigned char)c.

  --If c == EOF, there is no character to append.
    Returns a value other than EOF.

1 Returns EOF to indicate failure.
  Notes:
    The  function can alter the number of write positions available as a
    result of any call.
    To make a write position available,  the  function  reallocates  (or
    initially  allocates)  an  array  object with a sufficient number of
    elements n to hold the current array object (if any), plus at  least
    one  additional write position.  How many additional write positions
    are made available is otherwise unspecified.2) If palloc  is  not  a
    null  pointer,  the  function calls (*palloc)(n) to allocate the new
    dynamic array object.  Otherwise, it evaluates  the  expression  new
    charT[n].   In  either  case,  if the allocation fails, the function
    returns EOF.  Otherwise, it sets allocated in strmode.

2 To free a previously existing dynamic array object whose first element
  address  is  p:  If  pfree  is  not a null pointer, the function calls
  (*pfree)(p).  Otherwise, it evaluates the expression delete[] p.

3 If strmode & dynamic == 0, or if strmode & frozen != 0,  the  function
  cannot  extend the array (reallocate it with greater length) to make a
  write position available.

  int_type pbackfail(int_type c = EOF);

  +-------                 BEGIN BOX 3                -------+
  This needs to be rewritten in terms of consuming characters to be con­
  sistent with the revised protocol for pbackfail.
  +-------                  END BOX 3                 -------+

4 Puts back the character designated by c to the input sequence, if pos­
  sible, in one of three ways:

  --If c != EOF, if the input sequence has a putback position available,
    and if (char)c == gnext[-1], assigns gnext - 1 to gnext.
    Returns c.

  --If c != EOF, if the input sequence has a putback position available,
    and if strmode & constant is zero, assigns c to *--gnext.
    Returns c.

  --If c == EOF and if the input sequence has a putback position  avail­
    able, assigns gnext - 1 to gnext.
    Returns a value other than EOF.

  _________________________
  2) An implementation should consider alsize in making this decision.

5 Returns EOF to indicate failure.
  Notes:
    If  the  function  can succeed in more than one of these ways, it is
    unspecified which way is chosen.  The function can alter the  number
    of putback positions available as a result of any call.

  int_type underflow();

  +-------                 BEGIN BOX 4                -------+
  This needs to be rewritten in terms of consuming characters to be con­
  sistent with the revised protocol for underflow.
  +-------                  END BOX 4                 -------+

  Effects:
    Reads a character from the input sequence, if possible, without mov­
    ing the stream position past it, as follows:

  --If  the  input  sequence  has a read position available the function
    signals success by returning (unsignedchar)*gnext

  --Otherwise, if the current write next pointer pnext  is  not  a  null
    pointer and is greater than the current read end pointer gend, makes
    a read position available by: assigning to gend a value greater than
    gnext and no greater than pnext.
    Returns (unsigned char)*gnext.

6 Returns EOF to indicate failure.
  Notes:
    The  function  can alter the number of read positions available as a
    result of any call.

  pos_type seekoff(off_type off, seekdir way, openmode which = in | out);

  +-------                 BEGIN BOX 5                -------+
  Check vs. _lib.stringbuf.virtuals_
  +-------                  END BOX 5                 -------+

  Effects:
    Alters the stream position within one of the  controlled  sequences,
    if possible, as indicated in Table 5:

                        Table 5--seekoff positioning

  +-----------------------------------------------------------------------+
  |     Conditions                            Result                      |
  +-----------------------------------------------------------------------+
  (which & ios::in) != 0 positions the input sequence                     |
  +-----------------------------------------------------------------------+
  (which & ios::out) != 0positions the output sequence                    |
  +-----------------------------------------------------------------------+
  |Otherwise,                                                              |
  (which & (ios::in |    positions both the input and the output sequences|
  ios::out)) == (ios::in                                                  |
  | ios::out))                                                            |
  |and way == either                                                       |
  ios::beg or ios::end                                                    |
  +-----------------------------------------------------------------------+
  |Otherwise,             the positioning operation fails.                 |
  +-----------------------------------------------------------------------+

  +-------                 BEGIN BOX 6                -------+
  Comment: this condition is unclear.  If the 2nd condition is true,  is
  the  1st  condition  always true?  If so, the 2nd operation may occur,
  mayn't it?
  +-------                  END BOX 6                 -------+

7 For a sequence to be  positioned,  if  its  next  pointer  is  a  null
  pointer,  the  positioning  operation  fails.  Otherwise, the function
  determines newoff as indicated in Table 6:

                          Table 6--newoff values

        +---------------------------------------------------------+
        |      Condition                   newoff Value           |
        +---------------------------------------------------------+
        |way == ios::beg          0                               |
        +---------------------------------------------------------+
        |way == ios::cur          the next pointer minus the be­  |
        |                         ginning pointer (xnext - xbeg)  |
        +---------------------------------------------------------+
        |way == ios::end          seekhigh minus the beginning    |
        |                         pointer (seekhigh - xbeg)       |
        +---------------------------------------------------------+
        |If (newoff + off) <      the positioning operation fails |
        |(seeklow - xbeg),                                        |
        |or (seekhigh - xbeg) <                                   |
        |(newoff + off)                                           |
        +---------------------------------------------------------+

8 Otherwise, the function assigns xbeg  +  newoff  +  off  to  the  next
  pointer xnext.
  Returns:
    pos_type(newoff),  constructed  from the resultant offset newoff (of
    type off_type), that stores the resultant stream position, if possi­
    ble.   If  the  positioning  operation  fails, or if the constructed
    object cannot represent the resultant stream  position,  the  object
    stores an invalid stream position.

  +-------                 BEGIN BOX 7                -------+
  Note:  Need posT object which stores an invalid stream position.  Com­
  ment: Not clear if the constructed object cannot represent the  resul­
  tant stream position
  +-------                  END BOX 7                 -------+

  pos_type seekpos(pos_type sp, ios_base::openmode which
                    = ios_base::in | ios_base::out);

  Effects:
    Alters  the  stream position within one of the controlled sequences,
    if possible, to correspond to the stream position stored in  sp  (as
    described below).

  --If (which & ios::in) != 0, positions the input sequence.

  --If (which & ios::out) != 0, positions the output sequence.

  --If  the  function positions neither sequence, the positioning opera­
    tion fails.

9 For a sequence to be  positioned,  if  its  next  pointer  is  a  null
  pointer,  the  positioning  operation  fails.  Otherwise, the function
  determines newoff from sp.offset():

  --If newoff is an invalid stream position, has a  negative  value,  or
    has a value greater than (seekhigh - seeklow), the positioning oper­
    ation fails

  --Otherwise, the function adds newoff to the  beginning  pointer  xbeg
    and stores the result in the next pointer xnext.
  Returns:
    pos_type(newoff),  constructed  from the resultant offset newoff (of
    type off_type), that stores the resultant stream position, if possi­
    ble.   If  the  positioning  operation  fails, or if the constructed
    object cannot represent the resultant stream  position,  the  object
    stores an invalid stream position.
      streambuf<char>* setbuf(char* s, streamsize n);
  Effects:
    Performs  an  operation  that  is  defined separately for each class
    derived from strstreambuf.

  D.6.2  Class istrstream                              [depr.istrstream]
  namespace std {
    class istrstream : public basic_istream<char> {
    public:
      explicit istrstream(const char* s);
      explicit istrstream(char* s);
      istrstream(const char* s, streamsize n);
      istrstream(char* s, streamsize n);
      virtual ~istrstream();
      strstreambuf* rdbuf() const;
      char *str();
    private:
  //  strstreambuf sb;    exposition only
    };
  }

1 The  class  istrstream  supports  the  reading  of  objects  of  class
  strstreambuf.   It supplies a strstreambuf object to control the asso­
  ciated array object.  For the sake of exposition, the maintained  data
  is presented here as:

  --sb, the strstreambuf object.

  D.6.2.1  istrstream constructors                [depr.istrstream.cons]

  explicit istrstream(const char* s);
  explicit istrstream(char* s);

  Effects:
    Constructs  an  object  of  class  istrstream, initializing the base
    class with istream(&sb) and initializing sb with strstreambuf(s,0)).
    s shall designate the first element of an NTBS.

  istrstream(const char* s, streamsize n);

  Effects:
    Constructs  an  object  of  class  istrstream, initializing the base
    class with istream(&sb) and initializing sb with strstreambuf(s,n)).
    s  shall  designate  the first element of an array whose length is n
    elements, and n shall be greater than zero.

  D.6.2.2  Member functions                    [depr.istrstream.members]

  strstreambuf* rdbuf() const;

  Returns:
    (strstreambuf*)&sb.

  char* str();

  Returns:
    rdbuf()->str().

  D.6.3  Class ostrstream                              [depr.ostrstream]
  namespace std {
    class ostrstream : public basic_ostream<char> {
    public:
      ostrstream();
      ostrstream(char* s, int n, ios_base::openmode mode = ios_base::out);
      virtual ~ostrstream();
      strstreambuf* rdbuf() const;
      void freeze(int freezefl = 1);
      char* str();
      int pcount() const;
    private:
  //  strstreambuf sb;    exposition only
    };
  }

1 The  class  ostrstream  supports  the  writing  of  objects  of  class
  strstreambuf.   It supplies a strstreambuf object to control the asso­
  ciated array object.  For the sake of exposition, the maintained  data
  is presented here as:

  --sb, the strstreambuf object.

  D.6.3.1  ostrstream constructors                [depr.ostrstream.cons]

      ostrstream();

  Effects:
    Constructs  an  object  of  class  ostrstream, initializing the base
    class with ostream(&sb) and initializing sb with strstreambuf()).

  ostrstream(char* s, int n, ios_base::openmode mode = ios_base::out);

  Effects:
    Constructs an object of  class  ostrstream,  initializing  the  base
    class  with  ostream(&sb),  and initializing sb with one of two con­
    structors:

  --If mode & app == 0, then s shall designate the first element  of  an
    array of n elements.
    The constructor is strstreambuf(s, n, s).

  --If  mode  & app != 0, then s shall designate the first element of an
    array of n elements that contains an NTBS  whose  first  element  is
    designated by s.
    The constructor is strstreambuf(s, n, s + ::strlen(s)).3)
  _________________________
  3) The function signature strlen(const char*) is declared in <cstring>
  (_lib.c.strings_).

  D.6.3.2  Member functions                    [depr.ostrstream.members]

  strstreambuf* rdbuf() const;

  Returns:
    (strstreambuf*)&sb.

  void freeze(int freezefl = 1);

  Effects:
    Calls rdbuf()->freeze(freezefl).

  char* str();

  Returns:
    rdbuf()->str().

  int pcount() const;

  Returns:
    rdbuf()->pcount().

  D.6.4  Class strstream                                [depr.strstream]
  namespace std {
    class strstream
      : public basic_iostream<char> {
    public:
    // Types
      typedef char                                char_type;
      typedef typename ios_traits<char>::int_type int_type
      typedef typename ios_traits<char>::pos_type pos_type;
      typedef typename ios_traits<char>::off_type off_type;
    // consturctors/destructor
      strstream();
      strstream(char* s, int n,
                ios_base::openmode mode = ios_base::in|ios_base::out);
      virtual ~strstream();
    // Members:
      strstreambuf* rdbuf() const;
      void freeze(int freezefl = 1);
      int pcount() const;
      char* str();
    private:
    // strstreambuf sb; exposition only
    };
  }

1 The class strstream supports  reading  and  writing  from  objects  of
  classs strstreambuf.  It supplies a strstreambuf object to control the

  associated array object.  For the sake of exposition,  the  maintained
  data is presented here as

  --sb, the strstreambuf object.

  D.6.4.1  strstream constructors                  [depr.strstream.cons]

  ststream();

  Effects:
    Constructs an object of class strstream, initializing the base class
    with iostream(&sb).
  Effects:
    Constructs an object of class strstream, initializing the base class
    with iostream(&sb) and initializing sb with one of the two construc­
    tors:

  --If mode&app==0, then s shall designate the first element of an array
    of n elements.  The constructor is strstreambuf(s,n,s).

  --If mode&app==0, then s shall designate the first element of an array
    of n elements that contains an NTBS whose first  element  is  desig­
    nated by s.  The constructor is strstreambuf(s,n,s+::strlen(s)).

  virtual ~strstream()

  Effects:
    Destroys an object of class strstream.

  strstreambuf* rdbuf() const;

  Returns:
    &sb.

  void freeze(int freezefl = 1);

  Effects:
    Calls rdbuf()->freeze(freezefl).

  char* str();

  Returns:
    rdbuf()->str().

  int pcount() const;

  Returns:
    rdbuf()->pcount().