C++中的Type Alias

在C++中，我们通常使用typedef来实现type alias. 比如：

#include <cstdint>  //C standard int

typedef uint32_t points_t;  //points_t is alias of uint32_t
typedef uint64_t rank_t;  //rank_t is alias of uint64_t

struct score {

  points_t p {};
  rank_t r {};


}

 现在更modern的方式是, 是 using 来进行type alias, 请看：

#include <cstdint>  //C standard int

using points_t = uint32_t;  //points_t is alias of uint32_t
using rank_t = uint64_t;  //rank_t is alias of uint64_t

struct score {

  points_t p {};
  rank_t r {};


}