traveling time computation

• 走时计算

traveling time computation的用法和样例：

例句

1. Constant expressions, whose operands are all simple type constants, are evaluated at compilation time.
   编译时计算操作数均为简单类型常数的常数表达式。
2. The values in the new column are the values that were computed at the time the statement was executed.
   新列中的值是在执行该语句时计算出的值。