cmake_modules/orc.diff:1

• Adding this static_assert in the template destructor changes DataBuffer<T> into an ill-formed type for any non-trivially-copyable T as soon as the destructor is instantiated, which is a significant API/behavior change. If DataBuffer is intended to be restricted, enforce the constraint at the class level (and consider removing manual element-destruction loops for trivially-copyable types); otherwise, keep supporting non-trivial T by avoiding raw buffer reallocation/copy patterns that require trivial copyability.

diff --git a/c++/include/orc/MemoryPool.hh b/c++/include/orc/MemoryPool.hh

cmake_modules/orc.diff:1

• setData computes element counts as bufSize / sizeof(T), but the parameter name bufSize is ambiguous (bytes vs element count). If callers pass an element count (common for T* APIs), currentSize_/currentCapacity_ will be wrong. Consider changing the API to either (a) accept an element count explicitly (e.g., num_elems), or (b) rename to buffer_bytes and document that it must be byte-size; then ensure all callers match that contract.

diff --git a/c++/include/orc/MemoryPool.hh b/c++/include/orc/MemoryPool.hh

cmake_modules/orc.diff:1

• In the move constructor, the moved-from object is only reset when buffer.ownBuffer_ is true. When ownBuffer_ is false, the moved-from object keeps pointing at the external buffer with the original size/capacity, which is an unusual move semantic and can easily lead to accidental reuse of the moved-from buffer view. Consider resetting buffer.buf_ and sizes unconditionally in the move constructor while keeping ownBuffer_ = false semantics for ownership/freeing.

diff --git a/c++/include/orc/MemoryPool.hh b/c++/include/orc/MemoryPool.hh

cmake_modules/orc.diff:1

• This adds a new pure-virtual method to the public orc::Reader interface, which is a source/ABI breaking change for any external implementations of Reader. If backward compatibility matters for your ORC integration, prefer providing a non-pure virtual with a default implementation (e.g., returning {}) or introducing this as an optional capability on ReaderImpl rather than a required interface method.

diff --git a/c++/include/orc/MemoryPool.hh b/c++/include/orc/MemoryPool.hh

cmake_modules/orc.diff:1

• read_ranges is built from ranges without reserving capacity. Since the final size is known (ranges.size()), add read_ranges.reserve(ranges.size()) before the loop to avoid repeated reallocations when many ranges are returned.

diff --git a/c++/include/orc/MemoryPool.hh b/c++/include/orc/MemoryPool.hh

cmake_modules/arrow.diff:1

• Adding a new pure-virtual method to parquet::arrow::FileWriter is an ABI- and source-breaking change for any downstream custom FileWriter implementations. If compatibility with external implementations is required, consider providing a default non-pure virtual implementation (e.g., returning 0) or adding this via a separate interface/utility rather than changing the base contract.

diff --git a/cpp/src/parquet/arrow/schema.cc b/cpp/src/parquet/arrow/schema.cc