[Boost-users] [lexical_cast][1.33.0] Changed behavior from 1.32.0?

18 Nov 2005

      We've noticed some changed behavior in a module that's using lexical_cast, 
having gone from 1.32.0 to 1.33.0.  I tracked it down to this change:

1.32.0:
bool operator>>(InputStreamable &output)
{
    return !is_pointer<InputStreamable>::value &&
           stream >> output &&
            (stream >> std::ws).eof();
}

1.33.0:
bool operator>>(InputStreamable &output)
{
    return !is_pointer<InputStreamable>::value &&
           stream >> output &&
                       stream.get() ==
#if defined(__GNUC__) && (__GNUC__<3) && defined(BOOST_NO_STD_WSTRING)
// GCC 2.9x lacks std::char_traits<>::eof().
// We use BOOST_NO_STD_WSTRING to filter out STLport and libstdc++-v3
// configurations, which do provide std::char_traits<>::eof().
                           EOF;
#else
                           std::char_traits::eof();
#endif
}

It turns out that we are passing a string containing a number with a 
trailing space.  The 1.32.0 version of lexical_cast did not mind the 
trailing space, but the 1.33.0 version throws a bad_lexical_cast 
exception.  I found that if I change this:
                       stream.get() ==
to this:
                       (stream >> std::ws).get() ==

that my issue goes away, but the workaround for compilers without the 
eof() function still works....  Would it be possilbe to add this into 
1.34.0, or is this undesirable behavior?

--------------------------------
John Wismar
john.wismar@autozone.com

[Boost-users] [lexical_cast][1.33.0] Changed behavior from 1.32.0?

john.wismar＠autozone.com