diff --git a/cpp/doxygen/developer_guide/DEVELOPER_GUIDE.md b/cpp/doxygen/developer_guide/DEVELOPER_GUIDE.md index 311539efbfc..1c1052487f2 100644 --- a/cpp/doxygen/developer_guide/DEVELOPER_GUIDE.md +++ b/cpp/doxygen/developer_guide/DEVELOPER_GUIDE.md @@ -1483,6 +1483,17 @@ struct, and therefore `cudf::struct_view` is the data type of a `cudf::column` o `cudf::type_dispatcher` dispatches to the `struct_view` data type when invoked on a `STRUCT` column. +# Empty Columns + +The libcudf columns support empty, typed content. These columns have no data and no validity mask. +Empty strings or lists columns may or may not contain a child offsets column. +It is undefined behavior (UB) to access the offsets child of an empty strings or lists column. +Nested columns like lists and structs may require other children columns to provide the +nested structure of the empty types. + +Use `cudf::make_empty_column()` to create fixed-width and strings columns. +Use `cudf::empty_like()` to create an empty column from an existing `cudf::column_view`. + # cuIO: file reading and writing cuIO is a component of libcudf that provides GPU-accelerated reading and writing of data file