benchmark string copy vs move ctor

string_copy_vs_move.cpp

#include <benchmark/benchmark.h>
#include <string>

static void Copy(benchmark::State& state) {
  // Code inside this loop is measured repeatedly
  for (auto _ : state) {
    std::string src("a very long string to defeat small string optimization");
    std::string dst{src};
    benchmark::DoNotOptimize(dst);
  }
}
BENCHMARK(Copy);

static void Move(benchmark::State& state) {
  for (auto _ : state) {
    std::string src("a very long string to defeat small string optimization");
    std::string dst{std::move(src)};
    benchmark::DoNotOptimize(dst);
  }
}
BENCHMARK(Move);