Function swap

Exercises/Modules/Chapter 11/Soln11_03/words.sorting.cpp:4–9

Additional helpers for word::sort(Words&) */

/* Additional helpers for word::sort(Words&) */
void swap(words::Words& words, size_t first, size_t second)
{
  auto temp{ words[first] };
  words[first] = words[second];
  words[second] = temp;
}

void sort(words::Words& words, size_t start, size_t end);