Function increment

test/format-test.cc:174–182

Increment a number in a string.

// Increment a number in a string.
void increment(char* s) {
  for (int i = static_cast<int>(std::strlen(s)) - 1; i >= 0; --i) {
    if (s[i] != '9') {
      ++s[i];
      break;
    }
    s[i] = '0';
  }
}

TEST(util_test, increment) {
  char s[10] = "123";