Function coap_opt_put_string_with_len

pub unsafe extern "C" fn coap_opt_put_string_with_len(
    buf: *mut u8,
    lastonum: u16,
    optnum: u16,
    string: *const c_char,
    len: size_t,
    separator: c_char,
) -> size_t

@brief Encode the given string as multi-part option into buffer

@param[out] buf buffer to write to @param[in] lastonum number of previous option (for delta calculation), or 0 if first option @param[in] optnum option number to use @param[in] string string to encode as option @param[in] len length of the string @param[in] separator character used in @p string to separate parts

@return number of bytes written to @p buf