third_party/benchmark/test/link_main_test.cc

#include "benchmark/benchmark.h"

void BM_empty(benchmark::State& state) {
  for (auto _ : state) {
    auto iterations = static_cast<double>(state.iterations()) *
                      static_cast<double>(state.iterations());
    benchmark::DoNotOptimize(iterations);
  }
}
BENCHMARK(BM_empty);