Function nanocoap_cache_key_options_generate

pub unsafe extern "C" fn nanocoap_cache_key_options_generate(
    req: *const coap_pkt_t,
    cache_key: *mut c_void,
)

@brief Generates a cache key based on only the options in @p req

@param[in] req The request to generate the cache key from @param[out] cache_key The generated cache key of SHA256_DIGEST_LENGTH bytes