Function lazy_copy

cpp/src/arrow/util/range_benchmark.cc:82–92

std::copy with a lazy range as a source

// std::copy with a lazy range as a source
void lazy_copy(benchmark::State& state) {
  auto source = generate_junk(kSize);
  std::vector<int> target(kSize);
  auto lazy_range = internal::MakeLazyRange(
      [&source](int64_t index) { return source[index]; }, source.size());

  for (auto _ : state) {
    std::copy(lazy_range.begin(), lazy_range.end(), target.begin());
  }
  state.SetItemsProcessed(state.iterations() * kSize);
}

BENCHMARK(lazy_copy);