Method num_fields

cpp/src/arrow/type.cc:2309–2309

bool Schema::is_native_endian() const { return impl_->endianness_ == Endianness::Native; }

int Schema::num_fields() const { return static_cast<int>(impl_->fields_.size()); }

const std::shared_ptr<Field>& Schema::field(int i) const {
  DCHECK_GE(i, 0);