Function strings_to_kvm

r/src/schema.cpp:132–137

}

std::shared_ptr<arrow::KeyValueMetadata> strings_to_kvm(cpp11::strings metadata) {
  auto values = cpp11::as_cpp<std::vector<std::string>>(metadata);
  auto names = cpp11::as_cpp<std::vector<std::string>>(metadata.attr("names"));

  return std::make_shared<arrow::KeyValueMetadata>(std::move(names), std::move(values));
}

// [[arrow::export]]
std::shared_ptr<arrow::Schema> Schema__WithMetadata(