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Date: Mon, 08 Apr 2002 23:07:00 -0000
Message-ID: <20020409060741.23909.qmail@sources.redhat.com>
To: gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org, kingleo@gmx.at,
  paolo@gcc.gnu.org
From: bkoz@gcc.gnu.org
Reply-To: bkoz@gcc.gnu.org, gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org,
  kingleo@gmx.at, paolo@gcc.gnu.org, gcc-gnats@gcc.gnu.org
Subject: Re: libstdc++/5180: seekp() on fstreams opened in read only mode
X-SW-Source: 2002-04/txt/msg00515.txt.bz2
List-Id: <gcc-prs.sourceware.org>

Synopsis: seekp() on fstreams opened in read only mode

State-Changed-From-To: feedback->closed
State-Changed-By: bkoz
State-Changed-When: Mon Apr  8 23:07:37 2002
State-Changed-Why:
    The infinte loop is user error, I'm afraid. A better way to write that loop would be:
    
      while (in.good())
        {
          string s;
          getline(in, s);
          cout << s << endl;;
        }
    
    Anyway.
    
    This bug report actually crosses the paths of two library bugs, so this is perhaps why you might see differing interpretations of this code with other compilers and toolchains. 
    
    To wit:
    
      fstream in(name, std::ios::in);
      in.seekp(0); 
      state = in.rdstate();
    
    will give different results. I think state should be failbit, and here's why:
    
        basic_ostream::seekp(pos_type __pos)
        // DR 136
        this->rdbuf()->pubseekpos(__pos, ios_base::out);
        
    then
    
      filebuf::seekpos
      // DR 171
    
    best,
    benjamin

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=5180