Function MakeConcatenatedGenerator

cpp/src/arrow/util/async_generator.h:1513–1515

/// MergedGenerator does)
template <typename T>
AsyncGenerator<T> MakeConcatenatedGenerator(AsyncGenerator<AsyncGenerator<T>> source) {
  return MergedGenerator<T>(std::move(source), 1);
}

/// \see MakeEnumeratedGenerator
template <typename T>