Function safe_app::ffi::mutable_data::entries::mdata_keys_for_each

#[no_mangle]
pub unsafe extern "C" fn mdata_keys_for_each(
    app: *const App, 
    keys_h: MDataKeysHandle, 
    user_data: *mut c_void, 
    o_each_cb: unsafe extern "C" fn(_: *mut c_void, _: *const u8, _: usize), 
    o_done_cb: extern "C" fn(_: *mut c_void, _: FfiResult)
)

Iterate over the keys.

The o_each_cb callback is invoked once for each key, passing user data, pointer to key and key length.

The o_done_cb callback is invoked after the iteration is done, or in case of error.