The latest introduction of MDS conjecture, from a french sicentistla: Introduction-The Singleton Bound Singleton Bound. k< n-d+1, for any [n, k, d] code Proof Any 2 codewords disagree in the first n-d+l coordinates somewhere, so there are gn-d+i i

继承mono的单例和不继承mono的两种单例基类，不继承mono的单例基类使用加锁双重判定的懒汉式实现；需要设置为单例的类可直接继承使用