How to obtain pointer to data in nb::bytes object?

[jeffective]

I am wrapping this function:

int ecx_SDOwrite(ecx_contextt *context, uint16 Slave, uint16 Index, uint8 SubIndex,
                 boolean CA, int psize, const void *p, int Timeout);

How do I get a void* to the data in a nb::bytes object?

// p is a void pointer to the memory storing the bytes
// how do i obtain a pointer to the data in nb::bytes ?

auto SDOwrite(uint16 Slave, uint16 Index, uint8 SubIndex, boolean CA, nb::bytes data, int Timeout_us){
        
        // how do i get p? 
        return ecx_SDOwrite(&this->context, Slave, Index, SubIndex, CA, data.size(), p, Timeout_us);
    }

[jeffective]

i guess i could cast to a c string but then I have an extra null byte

[jeffective]

and the bytes cannot contain any null bytes

[nurpax]

I think it's ok for bytes to contain \0 chars in Python. I'm passing bytes values to through to my bindings and it works. This was changed recently:

18376ff

I didn't check how to go the other way though.

[jeffective]

Going to use a bind_vector of uint8_t instead and access it with .data() and .size()
https://nanobind.readthedocs.io/en/latest/api_extra.html#stl-vector-bindings