Re: Streams eof() and good()

From:
James Kanze <james.kanze@gmail.com>
Newsgroups:
comp.lang.c++
Date:
19 Apr 2007 10:26:32 -0700
Message-ID:
<1177003592.284089.73160@n59g2000hsh.googlegroups.com>
On Apr 19, 4:19 pm, Zeppe
<zeppe.remove.all.this.long.comm...@email.it> wrote:

Adrian wrote:

This code below produces "GOOD" on one platform and "EOF" on the
other.

I expect it to produce "EOF" as the second read would hit the end of
the stream.

Which result is correct?


Implementation defined, but in practice, I find it difficult to
believe that a correct implementation would not set eof.

#include <iostream>
#include <sstream>

int main(int argc, char *argv[])
{
  std::stringstream strm("5 4");

  int x;

  strm >> x;
  strm >> x;
  if(strm.good())
  {
    std::cout << "GOOD\n";
  }
  if(strm.eof())
  {
    std::cout << "EOF\n";
  }
  return 0;
}


It should be GOOD. What is the platform in which you are obtaining EOF?


According to what? I would expect EOF, but I don't think the
standard guarantees it.

The real question is what he is actually trying to do. In
practice, ios::good() is of no use what so ever, and ios::eof()
only after input has failed.

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