Doc. No.:   WG21/N0954R1=X3J16/96-0136R1
                                Date:       8 Jul 1996
                                Project:    C++ Standard Library
                                Reply to:   Nathan Myers
                                           <ncm@cantrip.org>

Iostream Resolutions (Myers) (Revision 1)
-----------------------------------------

The following are proposed resolutions for iostreams issues.

---------------

** Part:   001
** Issue:  27-001

** Proposed Resolution

In 27.6.1.1 [lib.istream] and 27.6.1.3 [lib.istream.unformatted],
replace the member getline with two members:

  istream_type& getline(char_type*, streamsize, char_type delim);
  istream_type& getline(char_type* p, streamsize n);

The latter member is to be described as:

  Returns: getline(p,n,widen('\n'));

---------------

** Part:   002
** Issue:  27-001

** Discussion

The need for a conversion of a char value to the character encoding in 
use for a stream is not restricted to newline.  Members for this purpose
would be useful to all users of iostream templates.

** Proposed Resolution

In 27.4.4 [lib.ios] and 27.4.4.2 [lib.basic.ios.members], add the
two members defined to call the corresponding member of the ctype locale 
facet in the stream: 

  char narrow(char_type c, char dfault) const;

  Returns: use_facet< ctype<char_type> >(getloc()).narrow(c,dfault)

  char_type widen(char c) const;

  Returns: use_facet< ctype<char_type> >(getloc()).widen(c)

---------------

** Part:   003
** Issue:  27-301
** Proposed Resolution

Add to introductory material in Clause 27 the statement:

  No function defined in any clause of this Standard, except for 
  ios_base::imbue itself, causes any standard member imbue to be called.  
  If any non-standard function calls imbue as a result of calling a 
  standard function (e.g.  if called via a standard virtual function 
  interface), the effect is undefined.

---------------

** Part:   004
** Issue:  27-904

** Discussion

In Santa Cruz we reinstated the bidirectional iostreams, but failed
to specify forward declarations for them in iosfwd.

** Proposed Resolution

Replace "Header <iosfwd> synopsis" by:

namespace {

  template <class charT> struct char_traits;
  template <> struct char_traits<char>;
  template <> struct char_traits<wchar_t>;
  
  template <class charT, class traits = char_traits<charT> > 
    class basic_ios;
  
  template <class charT, class traits = char_traits<charT> >
    class basic_streambuf;
  template <class charT, class traits = char_traits<charT> >
    class basic_istream;
  template <class charT, class traits = char_traits<charT> >
    class basic_ostream;
  
  template <class charT, class traits = char_traits<charT> >
    class basic_stringbuf;
  template <class charT, class traits = char_traits<charT> >
    class basic_istringstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_ostringstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_stringstream;
    
  template <class charT, class traits = char_traits<charT> >
    class basic_filebuf;
  template <class charT, class traits = char_traits<charT> >
    class basic_ifstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_ofstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_fstream;
  
  template <class charT, class traits = char_traits<charT> >
    class istreambuf_iterator;
  template <class charT, class traits = char_traits<charT> >
    class ostreambuf_iterator;
  
  typedef basic_ios<char>		ios;
  
  typedef basic_streambuf<char>		streambuf;
  typedef basic_istream<char>		istream;
  typedef basic_ostream<char>		ostream;
  typedef basic_iostream<char>		iostream;
  
  typedef basic_stringbuf<char>		stringbuf;
  typedef basic_istringstream<char>	istringstream;
  typedef basic_ostringstream<char>	ostringstream;
  typedef basic_stringstream<char>	stringstream;
  
  typedef basic_filebuf<char>		filebuf;
  typedef basic_ifstream<char>		ifstream;
  typedef basic_ofstream<char>		ofstream;
  typedef basic_fstream<char>		fstream;
  
  typedef basic_ios<wchar_t>		wios;
  
  typedef basic_streambuf<wchar_t>	wstreambuf;
  typedef basic_istream<wchar_t>		wistream;
  typedef basic_ostream<wchar_t>		wostream;
  typedef basic_iostream<wchar_t>		wiostream;
  
  typedef basic_stringbuf<wchar_t>	wstringbuf;
  typedef basic_istringstream<wchar_t>	wistringstream;
  typedef basic_ostringstream<wchar_t>	wostringstream;
  typedef basic_stringstream<wchar_t>	wstringstream;
  
  typedef basic_filebuf<wchar_t>		wfilebuf;
  typedef basic_ifstream<wchar_t>		wifstream;
  typedef basic_ofstream<wchar_t>		wofstream;
  typedef basic_fstream<wchar_t>		wfstream;
  
  typedef [implementation-defined]	streampos;
  typedef [implementation-defined]	wstreampos;
};

streampos and wstreampos are defined to be the same types as 
char_traits<char> and char_traits<wchar>, respectively.

---------------

** Part:   005
** Issue:  27-906
** Proposed Resolution

In each class template defined in Clauses 21 and 27 that take a
traits parameter, add the public member typedef:

  typedef traits traits_type;

---------------

** Part:   006
** Issue:  27-911

** Discussion

The traditional function in AT&T iostreams was sync_with_stdio(), because
it defaulted to unsynchronized.  We prefer for simplicity that it default
to synchronized (and possibly slow), with the means available to attain
greater speed at a cost in complexity.

** Proposed Resolution

Add to 27.4.3 [lib.ios.base] the public static member function of
ios_base:

  bool sync_with_stdio(bool sync = true);

  Returns: true, the first time it is called; otherwise, returns true
    if and only if the standard streams were still synchronized at the 
    time of the call.
  Effects: if any input or output operation has occurred using the 
    standard streams prior to the call, the effect is implementation-
    defined.  Otherwise, called with a false argument, it allows the 
    standard streams to operate independently of the standard C streams
    [footnote: with a possible performance improvement]; called with a 
    true argument it restores synchronization.


---------------

** Part:   006
** Issue:  22-057

The Library Working Group addressed the remaining portion of 
locale issue number 22-057 by approving the suggested change.

** Proposed Resolution:

In 22.1 [lib.locales], 22.2.6.1 [lib.locale.money.get], 22.2.6.1.1
[lib.locale.money.get.members], 22.2.6.2 [lib.locale.money.put], 
22.2.6.1.1 [lib.locale.money.put.members], and in the second and 
third tables under 22.1.1.1.1 [lib.locale.category], eliminate the 
parameter of type bool in templates money_get<> and money_put<>.  
In the tables, eliminate one of each resulting duplicate entry.  
In members get and do_get of money_get<>, and in put and do_put of 
money_put<> function, add an argument declared "bool intl" before 
the ios_base& argument.  This argument is passed along from the
non-virtual to the corresponding virtual member.

In the semantics for the do_get and do_put members, require that
if the "intl" parameter is true, the function uses members of the 
facet moneypunct<charT,true>, and if false uses members of the
facet moneypunct<charT,false>.