IronPython compatibility issue - explicit interface implementation #22
Description
🐞 Description of the bug
Explicit interface implementation is a feature of C# that allows a class to implement an interface but hide the implementation of users of the class, unless they explictly cast to the interface.
📝 Steps to reproduce
The following code leads to the exception AttributeError: 'NamedObject' object has no attribute 'Id'
namespace TestInheritance {
public interface IObject {
int Id { get; }
}
public class NamedObject : IObject {
private int _objectId;
private string _name;
public NamedObject(string name, int objectId) {
_objectId = objectId;
_name = name;
}
public string Name => _name;
#if PUBLIC_INHERITANCE
public int Id => _objectId;
#else
int IObject.Id => _objectId;
#endif
}
class Program {
static void Main(string[] args) {
var pyCode = @"
import TestInheritance
o = TestInheritance.NamedObject("hello", 1)
print(o.Id)";
Runtime.PythonDLL = "libpython3.9.dylib";
PythonEngine.Initialize();
using (Py.GIL()) {
PythonEngine.Exec(pyCode);
}
PythonEngine.Shutdown();
}
}
}
If the define #PUBLIC_INHERITANCE is set, the exception goes away. The current behavior is correct, according to how explicit interface implementation is meant to work in C#. However, IronPython allows python to call explicit interfaces without casting. This means that python scripts written for IronPython will not work for CPython. ansys-pythonnet should have an opt-in to support such calls without making it the default.