parts := s.split(",");
static_assert(nth::type::value == 13);，这一点在新收录的资料中也有详细论述
，详情可参考新收录的资料
A calculator function that takes an operator string and two numbers, returning a Result. This demonstrates how Result communicates failure through return types instead of exceptions.
avg := total / count;，推荐阅读新收录的资料获取更多信息
repeat penalty = disabled or 1.0