Function unpack

crates/stdlib/src/pystruct.rs:124–131

(
        fmt: IntoStructFormatBytes,
        buffer: ArgBytesLike,
        vm: &VirtualMachine,
    )

    #[pyfunction]
    fn unpack(
        fmt: IntoStructFormatBytes,
        buffer: ArgBytesLike,
        vm: &VirtualMachine,
    ) -> PyResult<PyTupleRef> {
        let format_spec = fmt.format_spec(vm)?;
        buffer.with_ref(|buf| format_spec.unpack(buf, vm))
    }

    #[derive(FromArgs)]
    struct UpdateFromArgs {