Function esp_idf_svc::sys::esp_netif_get_netif_impl_index

pub unsafe extern "C" fn esp_netif_get_netif_impl_index(
    esp_netif: *mut esp_netif_obj,
) -> i32

@brief Get net interface index from network stack implementation

@note This index could be used in setsockopt() to bind socket with multicast interface

@param[in] esp_netif Handle to esp-netif instance

@return implementation specific index of interface represented with supplied esp_netif