Result iterator api

python/pyarrow/_dataset.pyx

@@ -565,7 +565,7 @@ cdef class ScanTask:
         iterator = move(GetResultValue(move(self.task.Scan())))
 
         while True:
-            iterator.Next(&record_batch)
+            record_batch = GetResultValue(iterator.Next())
             if record_batch.get() == nullptr:
                 raise StopIteration()
             else:
@@ -737,7 +737,7 @@ cdef class Scanner:
         iterator = move(GetResultValue(move(self.scanner.Scan())))
 
         while True:
-            iterator.Next(&task)
+            task = GetResultValue(iterator.Next())
             if task.get() == nullptr:
                 raise StopIteration()
             else:

python/pyarrow/includes/libarrow.pxd

@@ -1686,7 +1686,7 @@ cdef extern from 'arrow/util/compression.h' namespace 'arrow' nogil:
 
 cdef extern from 'arrow/util/iterator.h' namespace 'arrow' nogil:
     cdef cppclass CIterator" arrow::Iterator"[T]:
-        CStatus Next(T* out)
+        CResult[T] Next()
         CStatus Visit[Visitor](Visitor&& visitor)