[C++-sig] undefined symbols with def_readonly

[Neal Becker]

Roman Yakovenko wrote:

> On Thu, Apr 10, 2008 at 4:35 PM, Stefan Seefeld <seefeld at sympatico.ca>
> wrote:
>> Neal Becker wrote:
>>
>>  > Surprisingly, this still doesn't work:
>>  > ...
>>  >     .setattr ("TAIL_BITS", turbo_enc_1_15::TAIL_BITS)
>>  >
>>  > ImportError: ../mod/turbo_enc_1_15.so: undefined symbol:
>>  > _ZN14turbo_enc_1_159TAIL_BITSE
>>
>>  And this:
>>
>>  int const tail_bits = turbo_enc_1_15::TAIL_BITS;
>>
>>  ...
>>  .setattr("TAIL_BITS", tail_bits)
>>
>>  ?
>>
>>  Note that the class_<>::setattr() method still takes a reference of its
>>  second argument, which, if the compiler doesn't optimize it away, emits
>>  a symbol reference. So, introducing this local 'tail_bits' variable has
>>  basically the same effect as defining turbo_enc_1_15::TAIL_BITS. The
>>  latter would obviously be the more proper solution to your problem, but
>>  if you don't want or can't do that, such a local variable may be a
>>  viable workaround. (Not sure how portable it is, though.)
> 
> May be you should try some other way:
> 
> using boost::python;
> scope().attr("TAIL_BITS") = object(TAIL_BITS);
> 

Will this make it an class variable?