add docstring and LICENSE/NOTICE notes

Signed-off-by: Junwang Zhao <[email protected]>

Author: zhjwpku

LICENSE

@@ -267,3 +267,17 @@ https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp
 
 MurmurHash3 was written by Austin Appleby, and is placed in the public
 domain. The author disclaims copyright to this source code.
+
+--------------------------------------------------------------------------------
+
+The file src/iceberg/util/checked_cast.h contains code adapted from
+
+https://github.com/apache/arrow/blob/main/cpp/src/arrow/util/checked_cast.h
+
+The file src/iceberg/util/visit_type.h contains code adapted from
+
+https://github.com/apache/arrow/blob/main/cpp/src/arrow/visit_type_inline.h
+
+Copyright: 2016-2025 The Apache Software Foundation.
+Home page: https://arrow.apache.org/
+License: https://www.apache.org/licenses/LICENSE-2.0

NOTICE

@@ -12,3 +12,7 @@ This product includes code from smhasher
  * MurmurHash3 was written by Austin Appleby, and is placed in the public
  * domain. The author hereby disclaims copyright to this source code.
  * https://github.com/aappleby/smhasher
+
+This product includes code from Apache Arrow
+ * Copyright 2016-2025 The Apache Software Foundation
+ * https://github.com/apache/arrow

src/iceberg/util/checked_cast.h

@@ -19,6 +19,11 @@
 
 #pragma once
 
+/// \file iceberg/util/checked_cast.h
+/// \brief Checked cast functions for dynamic_cast and static_cast.
+/// Adapted from Apache Arrow
+/// https://github.com/apache/arrow/blob/main/cpp/src/arrow/util/checked_cast.h
+
 #include <memory>
 #include <type_traits>
 #include <utility>

src/iceberg/util/visit_type.h

@@ -19,15 +19,17 @@
 
 #pragma once
 
+/// \file iceberg/util/visit_type.h
+/// \brief Visitor pattern for Iceberg types
+/// Adapted from Apache Arrow
+/// https://github.com/apache/arrow/blob/main/cpp/src/arrow/visit_type_inline.h
+
 #include "iceberg/result.h"
 #include "iceberg/type.h"
 #include "iceberg/util/checked_cast.h"
 #include "iceberg/util/unreachable.h"
 #include "iceberg/util/visitor_generate.h"
 
-// Adapted from Apache Arrow
-// https://github.com/apache/arrow/blob/main/cpp/src/arrow/visit_type_inline.h
-
 namespace iceberg {
 
 #define TYPE_VISIT_INLINE(TYPE_CLASS)                                   \

test/CMakeLists.txt

@@ -58,7 +58,8 @@ target_link_libraries(json_serde_test PRIVATE iceberg_static GTest::gtest_main
 add_test(NAME json_serde_test COMMAND json_serde_test)
 
 add_executable(util_test)
-target_sources(util_test PRIVATE expected_test.cc formatter_test.cc config_test.cc visit_type_test.cc)
+target_sources(util_test PRIVATE expected_test.cc formatter_test.cc config_test.cc
+                                 visit_type_test.cc)
 target_link_libraries(util_test PRIVATE iceberg_static GTest::gtest_main GTest::gmock)
 add_test(NAME util_test COMMAND util_test)