Testing with units in C++

strong.cpp

#include <iostream>
#include <vector>

#include "units.h"

using namespace units::literals;
using namespace units;

typedef units::length::meter_t Meters;
typedef units::length::foot_t Feet;

Meters foo(Meters m) { return m + Meters{2}; }

int main(int argc, char *argv[])
{
  std::vector<Feet> feet;
  for (size_t i = 0; i < (1 << 23); i++)
  {
    feet.push_back(Feet{static_cast<double>(i)});
  }

  Meters sum = 0_m;
  for (size_t i = 0; i < feet.size(); i++)
  {
    sum += foo(feet[i]);
  }

  std::cout << sum;
}

weak.cpp

#include <iostream>
#include <vector>

typedef double Meters;
typedef double Feet;

Meters foo(Meters m) { return m + Meters{2}; }

int main(int argc, char *argv[])
{
  std::vector<Feet> feet;
  for (size_t i = 0; i < (1 << 23); i++)
  {
    feet.push_back(Feet{static_cast<double>(i)});
  }

  Meters sum = 0;
  for (size_t i = 0; i < feet.size(); i++)
  {
    sum += foo(feet[i] * 0.3048);
  }

  std::cout << sum;
}

The units.h file is found here: https://github.com/nholthaus/units/blob/master/include/units.h

Compiling with clang++ --std=c++17 -o3 and profiling with Instruments on macOS results in 987ms run time for the strongly typed code and 429ms for the weakly typed code.