Re: VS2005 C++ Express basic_istream::get(buf, size, delim) bug

From:
"Igor Tandetnik" <itandetnik@mvps.org>
Newsgroups:
microsoft.public.vc.language
Date:
Tue, 3 Oct 2006 14:50:54 -0400
Message-ID:
<ewzlczx5GHA.2288@TK2MSFTNGP05.phx.gbl>
Terry G <tjgolubi@netins.net> wrote:

Is this a compiler bug? Does your C++ compiler produce the same
results? terry

=========================================================
File: try_get.cpp
=========================================================
#include <iostream>
#include <limits>

int main() {
 static char Line[1024];
 while (std::cin.get(Line, sizeof(Line), '\n')) {
   std::cin.ignore(std::numeric_limits<int>::max(), '\n');
   std::cout << ':' << Line << std::endl;
 }
} // main
=========================================================
Compiling: cl -EHsc try_get.cpp
Running: try_get < try_get.cpp
yields:
=========================================================
:#include <iostream>
:#include <limits>
=========================================================
Compiling: g++ try_get.cpp
Running: a < try_get.cpp
Yields:
=========================================================
:#include <iostream>
:#include <limits>

int main() {
 static char Line[1024];
 while (std::cin.get(Line, sizeof(Line), '\n')) {
   std::cin.ignore(std::numeric_limits<int>::max(), '\n');
   std::cout << ':' << Line << std::endl;
 }

:} // main


g++ is wrong. C++ standard about basic_istream::get : "27.6.1.3/8 If the
function stores no characters, it calls setstate(failbit)." Once failbit
is set, the stream object would evaluate to false in boolean context.
That's why the loop should terminate on an empty line.
--
With best wishes,
    Igor Tandetnik

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