[C++-sig] Re: implicitly_convertible and char*

[Dusty Leary]

full source code:
================================================
#define BOOST_PYTHON_STATIC_LIB

#include <boost/python.hpp>
using namespace boost::python;

struct X {
    std::string v;
    X(const std::string& s) : v(s) {}
    operator char*() const { return (char*)v.c_str(); }
};

void test_x(X& x) {
    char* x_string = x;
    printf("test_x: %s\n", x_string);
}

void test_string(char* s) {
    printf("test_string: %s\n", s);
}

BOOST_PYTHON_MODULE(test_string) {
    class_<X>("X", init<const std::string&>());
    def("test_x", test_x);
    def("test_string", test_string);
    implicitly_convertible<X, char*>();
}
================================================

interpreter:

>>> import test_string
>>> x = test_string.X("foo")
>>> test_string.test_x(x)
test_x: foo
>>> test_string.test_string("blah")
test_string: blah
>>> test_string.test_string(x)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
Boost.Python.ArgumentError: Python argument types in
    test_string.test_string(X)
did not match C++ signature:
    test_string(char *)




On Sun, 27 Jun 2004 20:39:56 -0400, David Abrahams
<dave at boost-consulting.com> wrote:
> 
> 
> Dusty Leary <dleary at gmail.com> writes:
> 
> > The implicitly_convertible sample at
> > http://boost.org/libs/python/doc/v2/implicit.html#implicitly_convertible-spec
> > works fine for me.
> >
> > However, changing "int" to "char*" makes it stop working.  Compiles
> > fine, won't invoke at runtime.
> >
> >>From the traceback:
> >
> > Boost.Python.ArgumentError: Python argument types in
> >     __testmodule__.test_string(X)
> > did not match C++ signature:
> >     test_string(char *)
> >
> > I am using MSVC7.1
> >
> > Any info?
> 
> Full source code of your example?
> Perhaps the problem is that X isn't actually convertible to char*?
> 
> --
> Dave Abrahams
> Boost Consulting
> http://www.boost-consulting.com
> 
> _______________________________________________
> C++-sig mailing list
> C++-sig at python.org
> http://mail.python.org/mailman/listinfo/c++-sig
>