2002-11-21 Phil Edwards <pme@gcc.gnu.org>

	* docs/doxygen/TODO:  Note change in clause 27 docs.
	* include/bits/basic_ios.h, include/bits/fpos.h,
	include/bits/ios_base.h, include/bits/stl_deque.h,
	include/bits/stl_iterator_base_types.h, include/std/std_fstream.h,
	include/std/std_iomanip.h, include/std/std_iosfwd.h,
	include/std/std_iostream.h, include/std/std_istream.h,
	include/std/std_ostream.h, include/std/std_sstream.h,
	include/std/std_streambuf.h:  Doxygenate all I/O entities.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@59325 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 496 insertions, 20 deletions

diff --git a/libstdc++-v3/include/std/std_istream.h b/libstdc++-v3/include/std/std_istream.h
index 8aa9123ed5c..7e050322328 100644
--- a/libstdc++-v3/include/std/std_istream.h
+++ b/libstdc++-v3/include/std/std_istream.h
@@ -46,7 +46,14 @@
 
 namespace std
 {
-  // 27.6.1.1 Template class basic_istream
+  // [27.6.1.1] Template class basic_istream
+  /**
+   *  @brief  Controlling input.
+   *
+   *  This is the base class for all input streams.  It provides text
+   *  formatting of all builtin types, and communicates with any class
+   *  derived from basic_streambuf to do the actual input.
+  */
   template<typename _CharT, typename _Traits>
     class basic_istream : virtual public basic_ios<_CharT, _Traits>
     {
@@ -68,10 +75,23 @@ namespace std
 
     protected:
       // Data Members:
+      /**
+       *  @if maint
+       *  The number of characters extracted in the previous unformatted
+       *  function; see gcount().
+       *  @endif
+      */
       streamsize 		_M_gcount;
 
     public:
-      // 27.6.1.1.1 Constructor/destructor:
+      // [27.6.1.1.1] constructor/destructor
+      /**
+       *  @brief  Base constructor.
+       *
+       *  This ctor is almost never called by the user directly, rather from
+       *  derived classes' initialization lists, which pass a pointer to
+       *  their own stream buffer.
+      */
       explicit 
       basic_istream(__streambuf_type* __sb)
       { 
@@ -79,16 +99,29 @@ namespace std
 	_M_gcount = streamsize(0);
       }
 
+      /**
+       *  @brief  Base destructor.
+       *
+       *  This does very little apart from providing a virtual base dtor.
+      */
       virtual 
       ~basic_istream() 
       { _M_gcount = streamsize(0); }
 
-      // 27.6.1.1.2 Prefix/suffix:
+      // [27.6.1.1.2] prefix/suffix
       class sentry;
       friend class sentry;
 
-      // 27.6.1.2 Formatted input:
-      // 27.6.1.2.3 basic_istream::operator>>
+      // [27.6.1.2] formatted input
+      // [27.6.1.2.3] basic_istream::operator>>
+      //@{
+      /**
+       *  @brief  Interface for manipulators.
+       *
+       *  Manuipulators such as @c std::ws and @c std::dec use these
+       *  functions in constructs like "std::cin >> std::ws".  For more
+       *  information, see the iomanip header.
+      */
       __istream_type&
       operator>>(__istream_type& (*__pf)(__istream_type&));
 
@@ -97,8 +130,36 @@ namespace std
 
       __istream_type&
       operator>>(ios_base& (*__pf)(ios_base&));
+      //@}
       
-      // 27.6.1.2.2 Arithmetic Extractors
+      // [27.6.1.2.2] arithmetic extractors
+      /**
+       *  @name Arithmetic Extractors
+       *
+       *  All the @c operator>> functions (aka <em>formatted input
+       *  functions</em>) have some common behavior.  Each starts by
+       *  constructing a temporary object of type std::basic_istream::sentry
+       *  with the second argument (noskipws) set to false.  This has several
+       *  effects, concluding with the setting of a status flag; see the
+       *  sentry documentation for more.
+       *
+       *  If the sentry status is good, the function tries to extract
+       *  whatever data is appropriate for the type of the argument.
+       *
+       *  If an exception is thrown during extraction, ios_base::badbit
+       *  will be turned on in the stream's error state without causing an
+       *  ios_base::failure to be thrown.  The original exception will then
+       *  be rethrown.
+      */
+      //@{
+      /**
+       *  @brief  Basic arithmetic extractors
+       *  @param  A variable of builtin type.
+       *  @return  @c *this if successful
+       *
+       *  These functions use the stream's current locale (specifically, the
+       *  @c num_get facet) to parse the input data.
+      */
       __istream_type& 
       operator>>(bool& __n);
       
@@ -140,92 +201,444 @@ namespace std
       __istream_type& 
       operator>>(void*& __p);
 
+      /**
+       *  @brief  Extracting into another streambuf.
+       *  @param  sb  A pointer to a streambuf
+       *
+       *  This function behaves like one of the basic arithmetic extractors,
+       *  in that it also constructs a sentry onject and has the same error
+       *  handling behavior.
+       *
+       *  If @a sb is NULL, the stream will set failbit in its error state.
+       *
+       *  Characters are extracted from this stream and inserted into the
+       *  @a sb streambuf until one of the following occurs:
+       *
+       *  - the input stream reaches end-of-file,
+       *  - insertion into the output buffer fails (in this case, the
+       *    character that would have been inserted is not extracted), or
+       *  - an exception occurs (and in this case is caught)
+       *
+       *  If the function inserts no characters, failbit is set.
+      */
       __istream_type& 
       operator>>(__streambuf_type* __sb);
+      //@}
       
-      // 27.6.1.3 Unformatted input:
+      // [27.6.1.3] unformatted input
+      /**
+       *  @brief  Character counting
+       *  @return  The number of characters extracted by the previous
+       *           unformatted input function dispatched for this stream.
+      */
       inline streamsize 
-      gcount(void) const 
+      gcount() const 
       { return _M_gcount; }
       
+      /**
+       *  @name Unformatted Input Functions
+       *
+       *  All the unformatted input functions have some common behavior.
+       *  Each starts by constructing a temporary object of type
+       *  std::basic_istream::sentry with the second argument (noskipws)
+       *  set to true.  This has several effects, concluding with the
+       *  setting of a status flag; see the sentry documentation for more.
+       *
+       *  If the sentry status is good, the function tries to extract
+       *  whatever data is appropriate for the type of the argument.
+       *
+       *  The number of characters extracted is stored for later retrieval
+       *  by gcount().
+       *
+       *  If an exception is thrown during extraction, ios_base::badbit
+       *  will be turned on in the stream's error state without causing an
+       *  ios_base::failure to be thrown.  The original exception will then
+       *  be rethrown.
+      */
+      //@{
+      /**
+       *  @brief  Simple extraction.
+       *  @return  A character, or eof().
+       *
+       *  Tries to extract a character.  If none are available, sets failbit
+       *  and returns traits::eof().
+      */
       int_type 
-      get(void);
-
+      get();
+
+      /**
+       *  @brief  Simple extraction.
+       *  @param  c  The character in which to store data.
+       *  @return  *this
+       *
+       *  Tries to extract a character and store it in @a c.  If none are
+       *  available, sets failbit and returns traits::eof().
+       *
+       *  @note  This function is not overloaded on signed char and
+       *         unsigned char.
+      */
       __istream_type& 
       get(char_type& __c);
 
+      /**
+       *  @brief  Simple multiple-character extraction.
+       *  @param  s  Pointer to an array.
+       *  @param  n  Maximum number of characters to store in @a s.
+       *  @param  delim  A "stop" character.
+       *  @return  *this
+       *
+       *  Characters are extracted and stored into @a s until one of the
+       *  following happens:
+       *
+       *  - @c n-1 characters are stored
+       *  - the input sequence reaches EOF
+       *  - the next character equals @a delim, in which case the character
+       *    is not extracted
+       *
+       * If no characters are stored, failbit is set in the stream's error
+       * state.
+       *
+       * In any case, a null character is stored into the next location in
+       * the array.
+       *
+       *  @note  This function is not overloaded on signed char and
+       *         unsigned char.
+      */
       __istream_type& 
       get(char_type* __s, streamsize __n, char_type __delim);
 
+      /**
+       *  @brief  Simple multiple-character extraction.
+       *  @param  s  Pointer to an array.
+       *  @param  n  Maximum number of characters to store in @a s.
+       *  @return  *this
+       *
+       *  Returns @c get(s,n,widen('\n')).
+      */
       inline __istream_type& 
       get(char_type* __s, streamsize __n)
       { return this->get(__s, __n, this->widen('\n')); }
 
+      /**
+       *  @brief  Extraction into another streambuf.
+       *  @param  sb  A streambuf in which to store data.
+       *  @param  delim  A "stop" character.
+       *  @return  *this
+       *
+       *  Characters are extracted and inserted into @a sb until one of the
+       *  following happens:
+       *
+       *  - the input sequence reaches EOF
+       *  - insertion into the output buffer fails (in this case, the
+       *    character that would have been inserted is not extracted)
+       *  - the next character equals @a delim (in this case, the character
+       *    is not extracted)
+       *  - an exception occurs (and in this case is caught)
+       *
+       * If no characters are stored, failbit is set in the stream's error
+       * state.
+      */
       __istream_type&
       get(__streambuf_type& __sb, char_type __delim);
 
+      /**
+       *  @brief  Extraction into another streambuf.
+       *  @param  sb  A streambuf in which to store data.
+       *  @return  *this
+       *
+       *  Returns @c get(sb,widen('\n')).
+      */
       inline __istream_type&
       get(__streambuf_type& __sb)
       { return this->get(__sb, this->widen('\n')); }
 
+      /**
+       *  @brief  String extraction.
+       *  @param  s  A character array in which to store the data.
+       *  @param  n  Maximum number of characters to extract.
+       *  @param  delim  A "stop" character.
+       *  @return  *this
+       *
+       *  Extracts and stores characters into @a s until one of the
+       *  following happens.  Note that these criteria are required to be
+       *  tested in the order listed here, to allow an input line to exactly
+       *  fill the @a s array without setting failbit.
+       *
+       *  -# the input sequence reaches end-of-file, in which case eofbit
+       *     is set in the stream error state
+       *  -# the next character equals @c delim, in which case the character
+       *     is extracted (and therefore counted in @c gcount()) but not stored
+       *  -# @c n-1 characters are stored, in which case failbit is set
+       *     in the stream error state
+       *
+       *  If no characters are extracted, failbit is set.  (An empty line of
+       *  input should therefore not cause failbit to be set.)
+       *
+       *  In any case, a null character is stored in the next location in
+       *  the array.
+      */
       __istream_type& 
       getline(char_type* __s, streamsize __n, char_type __delim);
 
+      /**
+       *  @brief  String extraction.
+       *  @param  s  A character array in which to store the data.
+       *  @param  n  Maximum number of characters to extract.
+       *  @return  *this
+       *
+       *  Returns @c getline(s,n,widen('\n')).
+      */
       inline __istream_type& 
       getline(char_type* __s, streamsize __n)
       { return this->getline(__s, __n, this->widen('\n')); }
 
+      /**
+       *  @brief  Discarding characters
+       *  @param  n  Number of characters to discard.
+       *  @param  delim  A "stop" character.
+       *  @return  *this
+       *
+       *  Extracts characters and throws them away until one of the
+       *  following happens:
+       *  - if @a n @c != @c std::numeric_limits<int>::max(), @a n
+       *    characters are extracted
+       *  - the input sequence reaches end-of-file
+       *  - the next character equals @a delim (in this case, the character
+       *    is extracted); note that this condition will never occur if
+       *    @a delim equals @c traits::eof().
+      */
       __istream_type& 
       ignore(streamsize __n = 1, int_type __delim = traits_type::eof());
       
+      /**
+       *  @brief  Looking ahead in the stream
+       *  @return  The next character, or eof().
+       *
+       *  If, after constructing the sentry object, @c good() is false,
+       *  returns @c traits::eof().  Otherwise reads but does not extract
+       *  the next input character.
+      */
       int_type 
-      peek(void);
+      peek();
       
+      /**
+       *  @brief  Extraction without delimiters.
+       *  @param  s  A character array.
+       *  @param  n  Maximum number of characters to store.
+       *  @return  *this
+       *
+       *  If the stream state is @c good(), extracts characters and stores
+       *  them into @a s until one of the following happens:
+       *  - @a n characters are stored
+       *  - the input sequence reaches end-of-file, in which case the error
+       *    state is set to @c failbit|eofbit.
+       *
+       *  @note  This function is not overloaded on signed char and
+       *         unsigned char.
+      */
       __istream_type& 
       read(char_type* __s, streamsize __n);
 
+      /**
+       *  @brief  Extraction until the buffer is exhausted, but no more.
+       *  @param  s  A character array.
+       *  @param  n  Maximum number of characters to store.
+       *  @return  The number of characters extracted.
+       *
+       *  Extracts characters and stores them into @a s depending on the
+       *  number of characters remaining in the streambuf's buffer,
+       *  @c rdbuf()->in_avail(), called @c A here:
+       *  - if @c A @c == @c -1, sets eofbit and extracts no characters
+       *  - if @c A @c == @c 0, extracts no characters
+       *  - if @c A @c > @c 0, extracts @c min(A,n)
+       *
+       *  The goal is to empty the current buffer, and to not request any
+       *  more from the external input sequence controlled by the streambuf.
+      */
       streamsize 
       readsome(char_type* __s, streamsize __n);
       
+      /**
+       *  @brief  Unextracting a single character.
+       *  @param  c  The character to push back into the input stream.
+       *  @return  *this
+       *
+       *  If @c rdbuf() is not null, calls @c rdbuf()->sputbackc(c).
+       *
+       *  If @c rdbuf() is null or if @c sputbackc() fails, sets badbit in
+       *  the error state.
+       *
+       *  @note  Since no characters are extracted, the next call to
+       *         @c gcount() will return 0, as required by DR 60.
+       *
+       *  @if maint
+       *  FIXME We don't comply with DR 60 here, _M_gcount is untouched.
+       *  @endif
+      */
       __istream_type& 
       putback(char_type __c);
 
+      /**
+       *  @brief  Unextracting the previous character.
+       *  @return  *this
+       *
+       *  If @c rdbuf() is not null, calls @c rdbuf()->sungetc(c).
+       *
+       *  If @c rdbuf() is null or if @c sungetc() fails, sets badbit in
+       *  the error state.
+       *
+       *  @note  Since no characters are extracted, the next call to
+       *         @c gcount() will return 0, as required by DR 60.
+      */
       __istream_type& 
-      unget(void);
-
+      unget();
+
+      /**
+       *  @brief  Synchronizing the stream buffer.
+       *  @return  0 on success, -1 on failure
+       *
+       *  If @c rdbuf() is a null pointer, returns -1.
+       *
+       *  Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
+       *  sets badbit and returns -1.
+       *
+       *  Otherwise, returns 0.
+       *
+       *  @note  This function does not count the number of characters
+       *         extracted, if any, and therefore does not affect the next
+       *         call to @c gcount().
+       *  @if maint
+       *  FIXME We don't comply with DR 60 here, _M_gcount is zeroed.
+       *  @endif
+      */
       int 
-      sync(void);
-
+      sync();
+
+      /**
+       *  @brief  Getting the current read position.
+       *  @return  A file position object.
+       *
+       *  If @c fail() is not false, returns @c pos_type(-1) to indicate
+       *  failure.  Otherwise returns @c rdbuf()->pubseekoff(0,cur,in).
+       *
+       *  @note  This function does not count the number of characters
+       *         extracted, if any, and therefore does not affect the next
+       *         call to @c gcount().
+      */
       pos_type 
-      tellg(void);
-
+      tellg();
+
+      /**
+       *  @brief  Changing the current read position.
+       *  @param  pos  A file position object.
+       *  @return  *this
+       *
+       *  If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos).  If
+       *  that function fails, sets failbit.
+       *
+       *  @note  This function does not count the number of characters
+       *         extracted, if any, and therefore does not affect the next
+       *         call to @c gcount().
+       *  @if maint
+       *  FIXME We don't comply with DR 60 here, _M_gcount is zeroed.
+       *  @endif
+      */
       __istream_type& 
       seekg(pos_type);
 
+      /**
+       *  @brief  Changing the current read position.
+       *  @param  off  A file offset object.
+       *  @param  dir  The direction in which to seek.
+       *  @return  *this
+       *
+       *  If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
+       *  If that function fails, sets failbit.
+       *
+       *  @note  This function does not count the number of characters
+       *         extracted, if any, and therefore does not affect the next
+       *         call to @c gcount().
+       *  @if maint
+       *  FIXME We don't comply with DR 60 here, _M_gcount is zeroed.
+       *  @endif
+      */
       __istream_type& 
       seekg(off_type, ios_base::seekdir);
+      //@}
     };
   
+  /**
+   *  @brief  Performs setup work for input streams.
+   *
+   *  Objects of this class are created before all of the standard
+   *  extractors are run.  It is responsible for "exception-safe prefix and
+   *  suffix operations," although only prefix actions are currently required
+   *  by the standard.  Additional actions may be added by the
+   *  implementation, and we list them in
+   *  http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#5
+   *  under [27.6] notes.
+  */
   template<typename _CharT, typename _Traits>
     class basic_istream<_CharT, _Traits>::sentry
     {
     public:
+      /// Easy access to dependant types.
       typedef _Traits 					traits_type;
       typedef basic_streambuf<_CharT, _Traits> 		__streambuf_type;
       typedef basic_istream<_CharT, _Traits> 		__istream_type;
       typedef typename __istream_type::__ctype_type 	__ctype_type;
       typedef typename _Traits::int_type		__int_type;
 
+      /**
+       *  @brief  The constructor performs all the work.
+       *  @param  is  The input stream to guard.
+       *  @param  noskipws  Whether to consume whitespace or not.
+       *
+       *  If the stream state is good (@a is.good() is true), then the
+       *  following actions are performed, otherwise the sentry state is
+       *  false ("not okay") and failbit is set in the stream state.
+       *
+       *  The sentry's preparatory actions are:
+       *
+       *  -# if the stream is tied to an output stream, @c is.tie()->flush()
+       *     is called to synchronize the output sequence
+       *  -# if @a noskipws is false, and @c ios_base::skipws is set in
+       *     @c is.flags(), the sentry extracts and discards whitespace
+       *     characters from the stream.  The currently imbued locale is
+       *     used to determine whether each character is whitespace.
+       *
+       *  If the stream state is still good, then the sentry state becomes
+       *  true ("okay").
+      */
       explicit 
       sentry(basic_istream<_CharT, _Traits>& __is, bool __noskipws = false);
 
+      /**
+       *  @brief  Quick status checking.
+       *  @return  The sentry state.
+       *
+       *  For ease of use, sentries may be converted to booleans.  The
+       *  return value is that of the sentry state (true == okay).
+      */
       operator bool() { return _M_ok; }
 
     private:
       bool _M_ok;
     };
 
-  // 27.6.1.2.3 Character extraction templates
+  // [27.6.1.2.3] character extraction templates
+  //@{
+  /**
+   *  @brief  Character extractors
+   *  @param  in  An input stream.
+   *  @param  c  A character reference.
+   *  @return  in
+   *
+   *  Behaves like one of the formatted arithmetic extractors described in
+   *  std::basic_istream.  After constructing a sentry object with good
+   *  status, this function extracts a character (if one is available) and
+   *  stores it in @a c.  Otherwise, sets failbit in the input stream.
+  */
   template<typename _CharT, typename _Traits>
     basic_istream<_CharT, _Traits>&
     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c);
@@ -239,7 +652,34 @@ namespace std
     basic_istream<char, _Traits>&
     operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
     { return (__in >> reinterpret_cast<char&>(__c)); }
-
+  //@}
+
+  //@{
+  /**
+   *  @brief  Character string extractors
+   *  @param  in  An input stream.
+   *  @param  s  A pointer to a character array.
+   *  @return  in
+   *
+   *  Behaves like one of the formatted arithmetic extractors described in
+   *  std::basic_istream.  After constructing a sentry object with good
+   *  status, this function extracts up to @c n characters and stores them
+   *  into the array starting at @a s.  @c n is defined as:
+   *
+   *  - if @c width() is greater than zero, @c n is width()
+   *  - otherwise @c n is "the number of elements of the largest array of
+   *    @c char_type that can store a terminating @c eos." [27.6.1.2.3]/6
+   *
+   *  Characters are extracted and stored until one of the following happens:
+   *  - @c n-1 characters are stored
+   *  - EOF is reached
+   *  - the next character is whitespace according to the current locale
+   *  - the next character is a null byte (i.e., @c charT() )
+   *
+   *  @c width(0) is then called for the input stream.
+   *
+   *  If no characters are extracted, sets failbit.
+  */
   template<typename _CharT, typename _Traits>
     basic_istream<_CharT, _Traits>&
     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s);
@@ -253,8 +693,15 @@ namespace std
     basic_istream<char,_Traits>&
     operator>>(basic_istream<char,_Traits>& __in, signed char* __s)
     { return (__in >> reinterpret_cast<char*>(__s)); }
+  //@}
 
   // 27.6.1.5 Template class basic_iostream
+  /**
+   *  @brief  Merging istream and ostream capabilities.
+   *
+   *  This class multiply inherits from the input and output stream classes
+   *  simply to provide a single interface.
+  */
   template<typename _CharT, typename _Traits>
     class basic_iostream
     : public basic_istream<_CharT, _Traits>, 
@@ -275,16 +722,45 @@ namespace std
       typedef basic_istream<_CharT, _Traits>		__istream_type;
       typedef basic_ostream<_CharT, _Traits>		__ostream_type;
 
+      /**
+       *  @brief  Constructor does nothing.
+       *
+       *  Both of the parent classes are initialized with the same
+       *  streambuf pointer passed to this constructor.
+      */
       explicit 
       basic_iostream(basic_streambuf<_CharT, _Traits>* __sb)
       : __istream_type(__sb), __ostream_type(__sb)
       { }
 
+      /**
+       *  @brief  Destructor does nothing.
+      */
       virtual 
       ~basic_iostream() { }
     };
 
-  // 27.6.1.4 Standard basic_istream manipulators
+  // [27.6.1.4] standard basic_istream manipulators
+  /**
+   *  @brief  Quick and easy way to eat whitespace
+   *
+   *  This manipulator extracts whitespace characters, stopping when the
+   *  next character is non-whitespace, or when the input sequence is empty.
+   *  If the sequence is empty, @c eofbit is set in the stream, but not
+   *  @c failbit.
+   *
+   *  The current locale is used to distinguish whitespace characters.
+   *
+   *  Example:
+   *  @code
+   *     MyClass   mc;
+   *
+   *     std::cin >> std::ws >> mc;
+   *  @endcode
+   *  will skip leading whitespace before calling operator>> on cin and your
+   *  object.  Note that the same effect can be achieved by creating a
+   *  std::basic_istream::sentry inside your definition of operator>>.
+  */
   template<typename _CharT, typename _Traits>
     basic_istream<_CharT, _Traits>& 
     ws(basic_istream<_CharT, _Traits>& __is);