Re: basic_istream>> differences 2003 vs. 2005
maynard wrote:
So I am trying to promote legacy C++ (unmanaged) code from VS 2003 to
VS 2005. Data is read from a comma-delimited file (containing
integers) with basic_istream::operator>>(). It seems what worked in
VS 2003 is no longer working correctly in 2005 (I believe failbit is
getting set when it reads a comma). The only thing I can think is
that the 2003 version of operator>> handled commas differently than
the 2005 version does?
VS2005 actually implements a weird feature that is indeed mandated by the
C++ standard in that it should use the current locale's numpunct facet or
something like that (I don't really remember). You should be able to locate
P.J. Plauger's respons in ms.public.vc.stl if you search around a bit, he
offered an explanation there.
Anyway, since your fileformat is language-agnostic, the preferred way to
handle this is to simply use a neutral locale:
ifstream in(...);
in.imbue(std::locale::classic());
Parsing should then work as before. Of course, writing should do the same.
Is setting failbit when operator>> encounters something it can't parse
new to 2005?
No, that is not new at all, it is the way things always worked. However,
depending on the circumstances, it simply stops parsing like e.g. when it
encounters whitespace.
Uli
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