Function AddCommonCasts

cpp/src/arrow/compute/kernels/scalar_cast_internal.cc:289–310

}

void AddCommonCasts(Type::type out_type_id, OutputType out_ty, CastFunction* func) {
  // From null to this type
  ScalarKernel kernel;
  kernel.exec = CastFromNull;
  kernel.signature = KernelSignature::Make({null()}, out_ty);
  kernel.null_handling = NullHandling::COMPUTED_NO_PREALLOCATE;
  kernel.mem_allocation = MemAllocation::NO_PREALLOCATE;
  DCHECK_OK(func->AddKernel(Type::NA, std::move(kernel)));

  // From dictionary to this type
  if (CanCastFromDictionary(out_type_id)) {
    // Dictionary unpacking not implemented for boolean or nested types.
    DCHECK_OK(func->AddKernel(Type::DICTIONARY, {InputType(Type::DICTIONARY)}, out_ty,
                              UnpackDictionary, NullHandling::COMPUTED_NO_PREALLOCATE,
                              MemAllocation::NO_PREALLOCATE));
  }

  // From extension type to this type
  DCHECK_OK(func->AddKernel(Type::EXTENSION, {InputType(Type::EXTENSION)}, out_ty,
                            CastFromExtension, NullHandling::COMPUTED_NO_PREALLOCATE,
                            MemAllocation::NO_PREALLOCATE));
}

}  // namespace internal
}  // namespace compute