I read the linked page, but this still feels like a bug to me. Or at least a wart. Like I said, the order sensitivity I can live with, because that only effects me. But the int vs bool problem is really obnoxious. C++ can tell an int from a bool, Python can tell an int from a bool, but library between them is discarding this information.
I agree that the best solution (from a purely technical view point) would be to rename the functions in the underlying c++ library, but I do not have control over that library and they have good reason to serve c++ users first and to resist interface breaking changes. From a UI viewpoint, the function is called foo. It foos the data that you pass to it. Having functions foo_int and foo_bool is not good style in either c++ or python. The problem seems to be that a bool implicitly cast to an int AND an int implicitly cast to a bool. If one of these could be blocked, then there would be some order that would make things work. -----Original Message----- From: cplusplus-sig-bounces+matthew.scouten=tradingtechnologies....@python.org [mailto:cplusplus-sig-bounces+matthew.scouten=tradingtechnologies....@python.org] On Behalf Of Roman Yakovenko Sent: Monday, March 16, 2009 12:00 PM To: Development of Python/C++ integration Subject: Re: [C++-sig] strange behavior with respect to numeric and Booleanoverloads 2009/3/16 Matthew Scouten (TT) <matthew.scou...@tradingtechnologies.com>: > So here is some strange behavior I ran across with BP. A take a look at this > example code: > > > > busybox.cpp: > > > > #include "stdafx.h" > > > > std::string foo_int (int arg) { return std::string("foo(int) > Called"); } > > std::string foo_double(double arg) { return std::string("foo(double) > Called"); } > > std::string foo_bool (bool arg) { return std::string("foo(bool) > Called"); } > > BOOST_PYTHON_MODULE(busybox) > > { > > bp::def("foo", foo_double); > > bp::def("foo", foo_bool); > > bp::def("foo", foo_int); > > > > } > > ... > > Now the order sensitivity is annoying, but I can figure out how to make it > work right, and then comment the dickens out of the code. The real killer is > that there does not seem to be any way to force BP to differentiate between > a bool and an int. The only thing that has worked is to apply a name skew > (ie: bp::def("foo_bool", foo_bool);). This works, but the users carp at me > for changing the interface from the underlying library. > > > > Is there a better work around? Yes: 1. rename your functions 2. introduce a function in Python, which selects "the right" function, based on argument type. > Is this a bug? Take a look on the following doc: http://www.language-binding.net/pyplusplus/documentation/functions/registration_order.html HTH -- Roman Yakovenko C++ Python language binding http://www.language-binding.net/ _______________________________________________ Cplusplus-sig mailing list Cplusplus-sig@python.org http://mail.python.org/mailman/listinfo/cplusplus-sig _______________________________________________ Cplusplus-sig mailing list Cplusplus-sig@python.org http://mail.python.org/mailman/listinfo/cplusplus-sig
