我应该争取一个成员职责单一的成员功能还是最小化成员变量的数量？

Question

I have a class called SolarPosition that has many member functions. I currently have a member function called CalculateSolarAzimuthAndAltitude which is a prime candidate for refactoring.

I found that the only way to refactor it to CalculateSolarAzimuth and CalculateSolarAltitude was to add an additional ten member variables, as some preliminary calculations are used by both functions.

Should I be happy with a member function with two responsibilities, or are multiple transient member variables a reasonable sacrifice in order to split it up?

Answer 1

My suggestion is to split up responsibilities into to two member functions. If that introduce ten addition transient variables, you can define a struct to group them together and define member from that struct in the SolarPosition class. that will improve readability as well.

If you still want to keep SolarPosition class much cleaner by hiding internal data variables from the class declaration, refer pimpl-idiom. for more information visit: Is the pImpl idiom really used in practice?

Answer 2

If you have that many additional variables to add, I suspect that you have an additional class hiding in your SolarPosition class. Think about extracting that class and go on from there.