iwyu

Change-Id: I9d333587c00d83ef5ad84a5b7c5052ebd24adabe

cpp/README.md

@@ -126,6 +126,9 @@ interfaces in this library as needed.
 The CUDA toolchain used to build the library can be customized by using the
 `$CUDA_HOME` environment variable.
 
+This library is still in Alpha stages, and subject to API changes without
+deprecation warnings.
+
 ### API documentation
 
 To generate the (html) API documentation, run the following command in the apidoc

cpp/build-support/iwyu/mappings/arrow-misc.imp

@@ -24,9 +24,10 @@
   { symbol: ["uint8_t", private, "<cstdint>", public ] },
   { symbol: ["_Node_const_iterator", private, "<flatbuffers/flatbuffers.h>", public ] },
   { symbol: ["unordered_map<>::mapped_type", private, "<flatbuffers/flatbuffers.h>", public ] },
-  { symbol: ["__alloc_traits<>::value_type", private, "<vector>", public ] },
   { symbol: ["move", private, "<utility>", public ] },
   { symbol: ["pair", private, "<utility>", public ] },
   { symbol: ["errno", private, "<cerrno>", public ] },
-  { symbol: ["posix_memalign", private, "<cstdlib>", public ] }
+  { symbol: ["posix_memalign", private, "<cstdlib>", public ] },
+  { include: ["<ext/alloc_traits.h>", private, "<vector>", public ] },
+  { include: ["<string.h>", private, "<cstring>", public ] }
 ]

cpp/src/arrow/compute/cast.cc

@@ -18,15 +18,21 @@
 #include "arrow/compute/cast.h"
 
 #include <cstdint>
+#include <cstring>
 #include <functional>
 #include <limits>
 #include <memory>
 #include <sstream>
+#include <string>
 #include <type_traits>
 
 #include "arrow/array.h"
+#include "arrow/buffer.h"
+#include "arrow/type.h"
 #include "arrow/type_traits.h"
+#include "arrow/util/bit-util.h"
 #include "arrow/util/logging.h"
+#include "arrow/util/macros.h"
 
 #include "arrow/compute/context.h"
 #include "arrow/compute/kernel.h"
@@ -426,7 +432,7 @@ Status Cast(FunctionContext* ctx, const Array& array,
   std::unique_ptr<UnaryKernel> func;
   RETURN_NOT_OK(GetCastFunction(*array.type(), out_type, options, &func));
 
-  // Allocate memory for output
+  // Data structure for output
   auto out_data = std::make_shared<ArrayData>(out_type, array.length());
 
   RETURN_NOT_OK(func->Call(ctx, array, out_data.get()));

cpp/src/arrow/compute/cast.h

@@ -20,12 +20,13 @@
 
 #include <memory>
 
-#include "arrow/array.h"
+#include "arrow/status.h"
 #include "arrow/util/visibility.h"
 
 namespace arrow {
 
-using internal::ArrayData;
+class Array;
+class DataType;
 
 namespace compute {