I'm desperately trying to expose a std::vector<bool>
class member to a Python class.
Here is my C++ class:
class Test
{
public:
std::vector<bool> test_fail;
std::vector<double> test_ok;
};
While the access and conversion of test_ok
of type double
(or int, float, ..) works, it does not for bool
!
Here is my Cython class:
cdef class pyTest:
cdef Test* thisptr
cdef public vector[bool] test_fail
cdef public vector[double] test_ok
cdef __cinit__(self):
self.thisptr = new Test()
self.test_fail = self.thisptr.test_fail # compiles and works if commented
self.test_ok = self.thisptr.test_ok
cdef __dealloc__(self):
del self.thisptr
The error I get is :
Error compiling Cython file:
------------------------------------------------------------
...
cdef extern from *:
ctypedef bool X 'bool'
^
------------------------------------------------------------
vector.from_py:37:13: 'bool' is not a type identifier
I'm using python 2.7.6 and Cython 0.20.2 (also tried 0.20.1).
I also tried with properties but it does not work either.
Addendum: I do have the from libcpp cimport bool
at the top of my pyx file, as well as the vector import.
What's wrong ?? I believe this might be a bug. Anyone knows how to circumvent this ? Thanks.
In order to define
boolean
objects in cython, they need to be defined asbint
. According to here:The bint of "boolean int" object is compiled to a c int, but get coerced to and from Cython as booleans.I have found a valid workaround, although it may not be optimal.
I have replaced the members types of the
pytest
class with python lists.The conversion is now done implicitely, as described in the documentation: http://docs.cython.org/src/userguide/wrapping_CPlusPlus.html#standard-library
So now, my class looks like this:
There's some extra C++ support you need to do. At the top of your .pyx file, add
I'd take a look inside that to find the other things you might need, like std::string and STL containers