Move and rename SizedInt to type_traits

AntoinePrv · AntoinePrv · commit 3ea4dd3de5bd · 2025-06-24T09:18:11.000+02:00
diff --git a/cpp/src/arrow/util/byte_stream_split_internal.h b/cpp/src/arrow/util/byte_stream_split_internal.h
@@ -20,6 +20,7 @@
 #include "arrow/util/endian.h"
 #include "arrow/util/simd.h"
 #include "arrow/util/small_vector.h"
+#include "arrow/util/type_traits.h"
 #include "arrow/util/ubsan.h"
 
 #include <algorithm>
@@ -112,56 +113,33 @@ void ByteStreamSplitDecodeSimd128(const uint8_t* data, int width, int64_t num_va
   }
 }
 
-template <int kNumBytes>
-struct grouped_bytes_impl;
-
-template <>
-struct grouped_bytes_impl<1> {
-  using type = int8_t;
-};
-
-template <>
-struct grouped_bytes_impl<2> {
-  using type = int16_t;
-};
-
-template <>
-struct grouped_bytes_impl<4> {
-  using type = int32_t;
-};
-
-template <>
-struct grouped_bytes_impl<8> {
-  using type = int64_t;
-};
-
-// Map a number of bytes to a type
-template <int kNumBytes>
-using grouped_bytes_t = typename grouped_bytes_impl<kNumBytes>::type;
-
 // Like xsimd::zip_lo, but zip groups of kNumBytes at once.
 template <int kNumBytes, int kBatchSize = 16,
           typename Batch = xsimd::make_sized_batch_t<int8_t, kBatchSize>>
 auto zip_lo_n(Batch const& a, Batch const& b) -> Batch {
+  using arrow::internal::SizedInt;
+
   if constexpr (kNumBytes == kBatchSize) {
     return a;
   } else {
     return xsimd::bitwise_cast<int8_t>(
-        xsimd::zip_lo(xsimd::bitwise_cast<grouped_bytes_t<kNumBytes>>(a),
-                      xsimd::bitwise_cast<grouped_bytes_t<kNumBytes>>(b)));
+        xsimd::zip_lo(xsimd::bitwise_cast<SizedInt<kNumBytes>>(a),
+                      xsimd::bitwise_cast<SizedInt<kNumBytes>>(b)));
   }
 }
 
 // Like xsimd::zip_hi, but zip groups of kNumBytes at once.
 template <int kNumBytes, int kBatchSize = 16,
           typename Batch = xsimd::make_sized_batch_t<int8_t, kBatchSize>>
 auto zip_hi_n(Batch const& a, Batch const& b) -> Batch {
+  using arrow::internal::SizedInt;
+
   if constexpr (kNumBytes == kBatchSize) {
     return b;
   } else {
     return xsimd::bitwise_cast<int8_t>(
-        xsimd::zip_hi(xsimd::bitwise_cast<grouped_bytes_t<kNumBytes>>(a),
-                      xsimd::bitwise_cast<grouped_bytes_t<kNumBytes>>(b)));
+        xsimd::zip_hi(xsimd::bitwise_cast<SizedInt<kNumBytes>>(a),
+                      xsimd::bitwise_cast<SizedInt<kNumBytes>>(b)));
   }
 }
 
diff --git a/cpp/src/arrow/util/type_traits.h b/cpp/src/arrow/util/type_traits.h
@@ -42,5 +42,32 @@ template <typename T>
 struct is_null_pointer : std::is_same<std::nullptr_t, typename std::remove_cv<T>::type> {
 };
 
+template <int kNumBytes>
+struct SizedIntImpl;
+
+template <>
+struct SizedIntImpl<1> {
+  using type = int8_t;
+};
+
+template <>
+struct SizedIntImpl<2> {
+  using type = int16_t;
+};
+
+template <>
+struct SizedIntImpl<4> {
+  using type = int32_t;
+};
+
+template <>
+struct SizedIntImpl<8> {
+  using type = int64_t;
+};
+
+// Map a number of bytes to a type
+template <int kNumBytes>
+using SizedInt = typename SizedIntImpl<kNumBytes>::type;
+
 }  // namespace internal
 }  // namespace arrow
