Re: libstdc++/9580: basic_filebuf<> with custom traits_type fails to link

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

The following reply was made to PR libstdc++/9580; it has been noted by GNATS.

From: Gabriel Dos Reis <gdr@integrable-solutions.net>
To: Paolo Carlini <pcarlini@unitus.it>
Cc: gcc-gnats@gcc.gnu.org, peturr02@ru.is, gcc-bugs@gcc.gnu.org
Subject: Re: libstdc++/9580: basic_filebuf<> with custom traits_type fails to link
Date: 13 Feb 2003 22:27:40 +0100

 Paolo Carlini <pcarlini@unitus.it> writes:
 
 | Gabriel Dos Reis wrote:
 | 
 | >This is something we should fix.  However I don't have necessary time
 | >next week to work on it. I'm sorry.
 | >
 | Well, so *I* will fix it ;)
 | 
 | Seriously, the PR is regression from 3.0.x, "due" to this checkin of
 | yours and
 
 Aha, I'm a silly boy :-(
 
 | Benjamin, apparently
 | (the problem is with std::basic_filebuf<char,
 | MyTraits>::_M_underflow_common(bool):
 | 
 | 2002-07-30  Benjamin Kosnik  <bkoz@redhat.com>
 |             Gabriel Dos Reis  <gdr@nerim.net>
 | 
 | ...
 | 
 |     * include/std/std_fstream.h: Declare _M_underflow_common
 |     specializations.
 |     * src/fstream.cc: New. Add _M_underflow_common specializations.
 |     * include/bits/fstream.tcc (filebuf::close): Use traits_type.
 |     (filebuf::_M_underflow_common(bool)): Remove generic version, as
 |     sys_ungetc and custom int_types don't get along.
 | 
 | ...
 | 
 | Can you please help me a bit understanding these Changelog entries?
 
 If I recall correctly, this change was made because of some
 differences in the way a narrow character stream based on
 char_traits<char> behaves and the way the general Traits may behave.
 At that point, I seem to recall that the goal was to have a general
 implementation  of that function plus the special case.  I'll have to
 go back and check my logs, unless Benjamin has a better recollection. 
 
 -- Gaby