Michele De Stefano wrote:
there is a much easier way to treat a FILE* as a C++ stream. The easy
way is to use my open source library (mds-utils,
http://code.google.com/p/mds-utils/).
Elegant use of boost::iostreams if I may say so. I've been looking for
some usecases for some boost.python modifications I've been playing with
so I tried incorporating your FileObj. Seems to work well. One can
wrap a function that takes a std::ostream& like this:
using mds_utils::python::FileObj;
// c++ function we're wrapping
void sayhello(std::ostream& os)
{
os << "*** hello ***\n";
}
//
// function object that converts object& and implements
// result_of protocol
//
struct conv {
typedef FileObj result_type;
result_type operator()(object& obj)
{
return FileObj(obj);
}
};
BOOST_PYTHON_MODULE(mod)
{
def("sayhello", as<void(conv(object&))>( &sayhello ));
// arg converter ^^^^^^^^^^^^^
};
In this case python sees "sayhello" as taking a bp::object.
The as<> might need some clarification.... It takes a function type
argument. Above, the argument is the type of a function that returns
void, which takes one argument, which is a function that returns conv
and takes one argument of type object&. In general, for a unary
function 'fn' returning type R it is:
as<R(T(U))>(&fn)
where T(U) means "convert the python object to C++ type U, then create a
temporary object T and use it to create result_of<T(U)>::type, then
convert that type to R and return to python". This is a little
boost::proto-ish. Maybe also a little like a C++1x concept map. You
could also provide a generic 'conv' struct, I skipped this so as not to
confuse things.
-t
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