We will extend the source code of the previous recipe with a minor change in src/sum_integers.cpp, where we will add a function - sum_integers_unused:

#include "sum_integers.hpp"

#include <vector>

int sum_integers(const std::vector<int> integers) {
  auto sum = 0;
  for (auto i : integers) {
    sum += i;
  }
  return sum;
}

int sum_integers_unused(const std::vector<int> integers) {
  auto sum = 0;
  for (auto i : integers) {
    sum += i;
  }
  return sum;
}

Our goal is to detect this unused code with a test coverage analysis, by using gcov (https://gcc.gnu.org/onlinedocs/gcc/Gcov.html). Apart from the preceding modification, we will use the unmodified sources of the previous recipe.