[BUG] enum class initializer throws NameError

[vyasr]

Describe the bug

In C++ initialization of an enum class should value initialize (at least in the case of an empty initializer list, I haven't dug too deeply into what should happen if given a real value). Cython compiles such code but then throws a NameError at runtime.

Code to reproduce the behaviour:

# distutils: language = c++


cdef enum class my_enum(int):
    a = 1
    b = 2


def f():
    my_enum()

This code compiles correctly, but at runtime I get:

(main) dt08% python -c 'import definitions; definitions.f()'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "definitions.pyx", line 10, in definitions.f
    my_enum()
NameError: name 'my_enum' is not defined

Expected behaviour

I think throwing an error during compilation would be an acceptable outcome here, if normal value initialization is not possible (especially if the non-empty initializer list case is actually UB; I haven't looked deeply enough yet to say either way).

OS

Linux

Python version

3.11.4

Cython version

3.0.0

Additional context

No response

[vyasr]

CC @shwina