GH-47500: [C++] Add QualifierAlignment to clang-format options (#47501)

Use the [QualifierAlignment](https://clang.llvm.org/docs/ClangFormatStyleOptions.html#qualifieralignment) clang-format option to make our code style more uniform.

* GitHub Issue: #47500

Authored-by: Antoine Pitrou <[email protected]>
Signed-off-by: Antoine Pitrou <[email protected]>

Author: pitrou

.clang-format

@@ -20,3 +20,4 @@ ColumnLimit: 90
 DerivePointerAlignment: false
 IncludeBlocks: Preserve
 IndentPPDirectives: AfterHash
+QualifierAlignment: Left

cpp/examples/parquet/low_level_api/encryption_reader_writer_all_crypto_options.cc

@@ -420,7 +420,7 @@ void InteropTestReadEncryptedParquetFiles(std::string root_path) {
   for (unsigned example_id = 0; example_id < vector_of_decryption_configurations.size();
        ++example_id) {
     PrintDecryptionConfiguration(example_id + 1);
-    for (auto const& file : files_in_directory) {
+    for (const auto& file : files_in_directory) {
       std::string exception_msg = "";
       if (!FileNameEndsWith(file, "parquet.encrypted"))  // Skip non encrypted files
         continue;

cpp/src/arrow/array/builder_nested.cc

@@ -48,7 +48,7 @@ template class BaseListViewBuilder<LargeListViewType>;
 // MapBuilder
 
 MapBuilder::MapBuilder(MemoryPool* pool, const std::shared_ptr<ArrayBuilder>& key_builder,
-                       std::shared_ptr<ArrayBuilder> const& item_builder,
+                       const std::shared_ptr<ArrayBuilder>& item_builder,
                        const std::shared_ptr<DataType>& type)
     : ArrayBuilder(pool), key_builder_(key_builder), item_builder_(item_builder) {
   auto map_type = internal::checked_cast<const MapType*>(type.get());

cpp/src/arrow/array/builder_nested.h

@@ -51,7 +51,7 @@ class VarLengthListLikeBuilder : public ArrayBuilder {
   /// Use this constructor to incrementally build the value array along with offsets and
   /// null bitmap.
   VarLengthListLikeBuilder(MemoryPool* pool,
-                           std::shared_ptr<ArrayBuilder> const& value_builder,
+                           const std::shared_ptr<ArrayBuilder>& value_builder,
                            const std::shared_ptr<DataType>& type,
                            int64_t alignment = kDefaultBufferAlignment)
       : ArrayBuilder(pool, alignment),
@@ -60,7 +60,7 @@ class VarLengthListLikeBuilder : public ArrayBuilder {
         value_field_(type->field(0)->WithType(NULLPTR)) {}
 
   VarLengthListLikeBuilder(MemoryPool* pool,
-                           std::shared_ptr<ArrayBuilder> const& value_builder,
+                           const std::shared_ptr<ArrayBuilder>& value_builder,
                            int64_t alignment = kDefaultBufferAlignment)
       : VarLengthListLikeBuilder(pool, value_builder,
                                  std::make_shared<TYPE>(value_builder->type()),
@@ -647,13 +647,13 @@ class ARROW_EXPORT FixedSizeListBuilder : public ArrayBuilder {
   /// Use this constructor to define the built array's type explicitly. If value_builder
   /// has indeterminate type, this builder will also.
   FixedSizeListBuilder(MemoryPool* pool,
-                       std::shared_ptr<ArrayBuilder> const& value_builder,
+                       const std::shared_ptr<ArrayBuilder>& value_builder,
                        int32_t list_size);
 
   /// Use this constructor to infer the built array's type. If value_builder has
   /// indeterminate type, this builder will also.
   FixedSizeListBuilder(MemoryPool* pool,
-                       std::shared_ptr<ArrayBuilder> const& value_builder,
+                       const std::shared_ptr<ArrayBuilder>& value_builder,
                        const std::shared_ptr<DataType>& type);
 
   Status Resize(int64_t capacity) override;

cpp/src/arrow/compute/api_aggregate.h

@@ -48,7 +48,7 @@ class ExecContext;
 class ARROW_EXPORT ScalarAggregateOptions : public FunctionOptions {
  public:
   explicit ScalarAggregateOptions(bool skip_nulls = true, uint32_t min_count = 1);
-  static constexpr char const kTypeName[] = "ScalarAggregateOptions";
+  static constexpr const char kTypeName[] = "ScalarAggregateOptions";
   static ScalarAggregateOptions Defaults() { return ScalarAggregateOptions{}; }
 
   /// If true (the default), null values are ignored. Otherwise, if any value is null,
@@ -72,7 +72,7 @@ class ARROW_EXPORT CountOptions : public FunctionOptions {
     ALL,
   };
   explicit CountOptions(CountMode mode = CountMode::ONLY_VALID);
-  static constexpr char const kTypeName[] = "CountOptions";
+  static constexpr const char kTypeName[] = "CountOptions";
   static CountOptions Defaults() { return CountOptions{}; }
 
   CountMode mode;
@@ -85,7 +85,7 @@ class ARROW_EXPORT CountOptions : public FunctionOptions {
 class ARROW_EXPORT ModeOptions : public FunctionOptions {
  public:
   explicit ModeOptions(int64_t n = 1, bool skip_nulls = true, uint32_t min_count = 0);
-  static constexpr char const kTypeName[] = "ModeOptions";
+  static constexpr const char kTypeName[] = "ModeOptions";
   static ModeOptions Defaults() { return ModeOptions{}; }
 
   int64_t n = 1;
@@ -103,7 +103,7 @@ class ARROW_EXPORT ModeOptions : public FunctionOptions {
 class ARROW_EXPORT VarianceOptions : public FunctionOptions {
  public:
   explicit VarianceOptions(int ddof = 0, bool skip_nulls = true, uint32_t min_count = 0);
-  static constexpr char const kTypeName[] = "VarianceOptions";
+  static constexpr const char kTypeName[] = "VarianceOptions";
   static VarianceOptions Defaults() { return VarianceOptions{}; }
 
   int ddof = 0;
@@ -119,7 +119,7 @@ class ARROW_EXPORT SkewOptions : public FunctionOptions {
  public:
   explicit SkewOptions(bool skip_nulls = true, bool biased = true,
                        uint32_t min_count = 0);
-  static constexpr char const kTypeName[] = "SkewOptions";
+  static constexpr const char kTypeName[] = "SkewOptions";
   static SkewOptions Defaults() { return SkewOptions{}; }
 
   /// If true (the default), null values are ignored. Otherwise, if any value is null,
@@ -154,7 +154,7 @@ class ARROW_EXPORT QuantileOptions : public FunctionOptions {
                            enum Interpolation interpolation = LINEAR,
                            bool skip_nulls = true, uint32_t min_count = 0);
 
-  static constexpr char const kTypeName[] = "QuantileOptions";
+  static constexpr const char kTypeName[] = "QuantileOptions";
   static QuantileOptions Defaults() { return QuantileOptions{}; }
 
   /// probability level of quantile must be between 0 and 1 inclusive
@@ -178,7 +178,7 @@ class ARROW_EXPORT TDigestOptions : public FunctionOptions {
   explicit TDigestOptions(std::vector<double> q, uint32_t delta = 100,
                           uint32_t buffer_size = 500, bool skip_nulls = true,
                           uint32_t min_count = 0);
-  static constexpr char const kTypeName[] = "TDigestOptions";
+  static constexpr const char kTypeName[] = "TDigestOptions";
   static TDigestOptions Defaults() { return TDigestOptions{}; }
 
   /// probability level of quantile must be between 0 and 1 inclusive
@@ -268,7 +268,7 @@ class ARROW_EXPORT PivotWiderOptions : public FunctionOptions {
                              UnexpectedKeyBehavior unexpected_key_behavior = kIgnore);
   // Default constructor for serialization
   PivotWiderOptions();
-  static constexpr char const kTypeName[] = "PivotWiderOptions";
+  static constexpr const char kTypeName[] = "PivotWiderOptions";
   static PivotWiderOptions Defaults() { return PivotWiderOptions{}; }
 
   /// The values expected in the pivot key column
@@ -283,7 +283,7 @@ class ARROW_EXPORT IndexOptions : public FunctionOptions {
   explicit IndexOptions(std::shared_ptr<Scalar> value);
   // Default constructor for serialization
   IndexOptions();
-  static constexpr char const kTypeName[] = "IndexOptions";
+  static constexpr const char kTypeName[] = "IndexOptions";
 
   std::shared_ptr<Scalar> value;
 };