Function type_check

crates/vm/src/builtins/union.rs:205–215

(arg: PyObjectRef, vm: &VirtualMachine)

}

fn type_check(arg: PyObjectRef, vm: &VirtualMachine) -> PyResult<PyObjectRef> {
    // Fast path to avoid calling into typing.py
    if is_unionable(arg.clone(), vm) {
        return Ok(arg);
    }
    let message_str: PyObjectRef = vm
        .ctx
        .new_str("Union[arg, ...]: each arg must be a type.")
        .into();
    call_typing_func_object(vm, "_type_check", (arg, message_str))
}

fn has_union_operands(a: PyObjectRef, b: PyObjectRef, vm: &VirtualMachine) -> bool {
    let union_type = vm.ctx.types.union_type;