Cannot give Option function argument a default value but still pass None explicitly

[birkenfeld]

Using 0.10. Extension module code:

use pyo3::prelude::*;
use pyo3::wrap_pyfunction;

#[pymodule]
fn test(_py: Python, m: &PyModule) -> PyResult<()> {
    m.add_wrapped(wrap_pyfunction!(testfn))
}

#[pyfunction(arg="true")]
fn testfn(arg: Option<bool>) {
    println!("{:?}", arg);
}

Test in interpreter:

>>> import test
>>> test.testfn()
Some(true)
>>> test.testfn(True)
Some(true)
>>> test.testfn(False)
Some(false)
>>> test.testfn(None)
Some(true)

There is no way to make the argument None anymore...

[davidhewitt]

Thanks, see #936