pitrou commented on code in PR #41373: URL: https://github.com/apache/arrow/pull/41373#discussion_r1626140322
########## cpp/src/arrow/util/gather_internal.h: ########## @@ -0,0 +1,287 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#pragma once + +#include <cassert> +#include <cstddef> +#include <cstdint> +#include "arrow/array/data.h" +#include "arrow/util/bit_block_counter.h" +#include "arrow/util/bit_run_reader.h" +#include "arrow/util/bit_util.h" +#include "arrow/util/bitmap_ops.h" +#include "arrow/util/macros.h" + +// Implementation helpers for kernels that need to load/gather fixed-width +// data from multiple, arbitrary indices. +// +// https://en.wikipedia.org/wiki/Gather/scatter_(vector_addressing) + +namespace arrow::internal { +inline namespace gather_internal { Review Comment: > Many STL classes live in inline namespaces like this so they can fully disappear at the code that uses them. I guess I don't understand why using an inline namespace would open up more optimization opportunities. Do you have a reference that explains this? Or is it just a side effect of whatever compiler version you're using? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
