[C++-sig] make_constructor strangeness

[Neal Becker]

I noticed that the following didn't work:

  pyclass
    .def(init<size_type>())
    .def("__init__", make_constructor(vector_from_object<value_type>))

where size_type is some size (probably size_t), value_type could be double
or std::complex<double>, and vector_from_object has sig:
template<typename T>
inline vector<T>* vector_from_object (object& newobject) {
 
It seems if I try to construct an object using an argument of type int, the
init<size_type> is being ignored (silently), and the call goes to
vector_from_object.

I guess you can't dispatch an overload to a function that takes "object". 
Problem is, it seems to act unpredictably, and fails silently.

Unpredictably, because I used the same code for the case where value_type
was double, and also when it was std::complex<double>, and the two acted
differently.  The complex called with an int did call the first
constructor, while the double one called the second.  AFAICT, there were no
other significant differences between the two cases.