Re: [boost] gcc: timer patch, and ios_base workarounds

From: Greg Chicares (chicares_at_[hidden])
Date: 2001-04-15 20:19:53

Jens Maurer wrote:
> 
> Greg Chicares wrote:
> 
> > Patch two: [edited for brevity]
> > +   namespace std { class ios_base : public ios{}; }
> 
> This is not good if it's repeated in several header files and
> thus multiple definitions of ios_base are encountered.

Thank you; I hadn't perceived that problem...yet.

> > Is this preferable to the workaround
> >   std::istream::fmtflags f_;      // old GNU c++ lib has no ios_base
> > in random.hpp?
> 
> This work-around is entirely conformant with both old and new
> iostreams.  Therefore, I believe this workaround (albeit a bit
> strange to the eye) is acceptable, and superior to messing around
> with defining ios_base.  It's an implementation-level
> workaround anyway, so interfaces are not affected.

Then I propose the following changes:

*** boost/progress.hpp
-     std::ios_base::fmtflags old_flags = _os.setf( std::ios_base::fixed,
-                                                  std::ios_base::floatfield );
+     // old GNU c++ lib has no ios_base
+     std::istream::fmtflags old_flags = _os.setf( std::istream::fixed,
+                                                  std::istream::floatfield );

With this change (and use of <boost/limits.hpp> instead of <limits>
in timer.hpp as previously discussed), gcc-2.95.2 now passes the
timer test. The only other compiler I have to test with is borland
C++ 5.5; it still passes too.

*** libs/regex/src/cpp_regex_traits.cpp
  [see attachment: run 'patch < diffs' to apply; tested with gnu patch 2.5]

The library builds with gcc-2.95.2 . I'm not sure how to run the
tests; I did build the 'r2' binary in libs/regex/demo/regress,
and running it gives
  ./r2 tests.txt
  871 lines, 629 tests completed in file tests.txt
but I can't readily see how to interpret this.

*** libs/random/nondet_random.html
No change proposed. The language
  The pseudo-device should never signal an error or end-of-file.
  Otherwise, std::ios_base::failure is thrown.
                  ^^^^^^^^
remains valid; how the 'failure' member is found for a nonconforming
compiler is an implementation detail that doesn't belong in the
html documentation.


*** /boost/boost_1_21_1x/libs/regex/src/cpp_regex_traits.cpp	Wed Mar 14 11:11:56 2001
--- ./cpp_regex_traits.cpp	Sun Apr 15 20:22:36 2001
***************
*** 89,94 ****
  protected:
     std::basic_streambuf<charT, traits>* setbuf(char_type* s, streamsize n);
!    typename parser_buf<charT, traits>::pos_type seekpos(pos_type sp, ::std::ios_base::openmode which);
!    typename parser_buf<charT, traits>::pos_type seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which);
  private:
     parser_buf& operator=(const parser_buf&);
--- 89,94 ----
  protected:
     std::basic_streambuf<charT, traits>* setbuf(char_type* s, streamsize n);
!    typename parser_buf<charT, traits>::pos_type seekpos(pos_type sp, ::std::istream::openmode which);
!    typename parser_buf<charT, traits>::pos_type seekoff(off_type off, ::std::istream::seekdir way, ::std::istream::openmode which);
  private:
     parser_buf& operator=(const parser_buf&);
***************
*** 106,112 ****
  template<class charT, class traits>
  typename parser_buf<charT, traits>::pos_type
! parser_buf<charT, traits>::seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which)
  {
!    if(which & ::std::ios_base::out)
        return pos_type(off_type(-1));
     int size = this->egptr() - this->eback();
--- 106,112 ----
  template<class charT, class traits>
  typename parser_buf<charT, traits>::pos_type
! parser_buf<charT, traits>::seekoff(off_type off, ::std::istream::seekdir way, ::std::istream::openmode which)
  {
!    if(which & ::std::istream::out)
        return pos_type(off_type(-1));
     int size = this->egptr() - this->eback();
***************
*** 115,129 ****
     switch(way)
     {
!    case ::std::ios_base::beg:
        if((off < 0) || (off > size))
           return pos_type(off_type(-1));
        else
           this->setg(g, g + off, g + size);
!    case ::std::ios_base::end:
        if((off < 0) || (off > size))
           return pos_type(off_type(-1));
        else
           this->setg(g, g + size - off, g + size);
!    case ::std::ios_base::cur:
     {
        int newpos = pos + off;
--- 115,129 ----
     switch(way)
     {
!    case ::std::istream::beg:
        if((off < 0) || (off > size))
           return pos_type(off_type(-1));
        else
           this->setg(g, g + off, g + size);
!    case ::std::istream::end:
        if((off < 0) || (off > size))
           return pos_type(off_type(-1));
        else
           this->setg(g, g + size - off, g + size);
!    case ::std::istream::cur:
     {
        int newpos = pos + off;
***************
*** 139,145 ****
  template<class charT, class traits>
  typename parser_buf<charT, traits>::pos_type
! parser_buf<charT, traits>::seekpos(pos_type sp, ::std::ios_base::openmode which)
  {
!    if(which & ::std::ios_base::out)
        return pos_type(off_type(-1));
     int size = this->egptr() - this->eback();
--- 139,145 ----
  template<class charT, class traits>
  typename parser_buf<charT, traits>::pos_type
! parser_buf<charT, traits>::seekpos(pos_type sp, ::std::istream::openmode which)
  {
!    if(which & ::std::istream::out)
        return pos_type(off_type(-1));
     int size = this->egptr() - this->eback();