[C++-sig] Re: Construct for c++ class with reference

[Neal D. Becker]

David Abrahams wrote:

> "Neal D. Becker" <ndbecker2 at verizon.net> writes:
> 
>> How should I wrap this (simplified example):
>>
>> struct X {
>>   X (int& _x) : x (_x) {}
>>   int& x;
>> };
> 
> References to builtins are a difficult case.  If it were a class you
> could use a read_write property.  Python ints are immutable, so you
> have to decide how you'd like to see this translated.  What do you
> want the Python interface to be?
> 

Actually, I wanted to use this with a class.  This code is meant to wrap
boost random number stuff.  I acutally found an answer by asking pyste. 
This code seems to work:

  class_<boost_normal_wrap> ("normal", init<const boost_normal_wrap&>())
    .def (init<rng_t&, double>())
    .def ("Compute", &boost_normal_wrap::Compute)
    ;

I got runtime error if I tried it like this (from memory, hope I got this
correct):

  class_<boost_normal_wrap> ("normal", init<rng_t&, double>())
    .def ("Compute", &boost_normal_wrap::Compute)
    ;

I don't acually know why #1 works and #2 doesn't.

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