Function gcoap_obs_send

pub unsafe extern "C" fn gcoap_obs_send(
    buf: *const u8,
    len: size_t,
    resource: *const coap_resource_t,
) -> size_t

@brief Sends a buffer containing a CoAP Observe notification to the observer registered for a resource

Assumes a single observer for a resource.

@param[in] buf Buffer containing the PDU @param[in] len Length of the buffer @param[in] resource Resource to send

@return length of the packet @return 0 if cannot send