C++库函数收集

1. 数值类型极限值

std::numeric_limits<double>::max();

2. 随机数发生函数
   2.1 均匀分布

The  drand48() and erand48() functions return nonnegative double-preci‐
       sion floating-point values  uniformly  distributed  over  the  interval
       [0.0, 1.0).