Re: [boost] regression test feature requests

From: Ed Brey (brey_at_[hidden])
Date: 2001-01-23 14:45:57

From: "Jens Maurer" <Jens.Maurer_at_[hidden]>
>
> > In that case, the results at stdout are perfectly informative; I don't
> > really need an .html result. Could we just skip it?
>
> Difficult.  All of regression.cpp depends on having a valid ostream,
> and there is no "nullstream" or similar.  And ofstream("/dev/null") is
> not portable.

Sounds like a call for a boost library (or library portion).  Seems like
an easy one, since the base stream buffer class does nothing by default.
The simple version of a nullstream is just this:

class nullstreambuf: public std::streambuf {};
nullstreambuf nullbuf;
std::iostream nullstream(&nullbuf);

In more detail, we would really need to cater to istream/ostream specifics
and templated types, and to separate interface from implementation, so the
boost library would look more like this:

// nullstream.hpp
template<typename E>
 class basic_nullstreambuf: public std::basic_streambuf<E> {};
typedef basic_nullstreambuf<char> nullstreambuf;
typedef basic_nullstreambuf<wchar_t> wnullstreambuf;

extern nullstreambuf nullbuf;
extern std::iostream nullstream;
extern std::istream nullistream;
extern std::ostream nullostream;

extern wnullstreambuf wnullbuf;
extern std::wiostream wnullstream;
extern std::wistream wnullistream;
extern std::wostream wnullostream;

// nullstream.cpp
nullstreambuf nullbuf;
std::iostream nullstream(&nullbuf);
std::istream nullistream(&nullbuf);
std::ostream nullostream(&nullbuf);

wnullstreambuf wnullbuf;
std::wiostream wnullstream(&wnullbuf);
std::wistream wnullistream(&wnullbuf);
std::wostream wnullostream(&wnullbuf);

An example usage would be like this:

if (filename) {  // if output file specified:
    ifstream filestream(filename);
    do_work(filestream);
} else  // No output file:
    do_work(boost::nullstream);