C ++类/结构中的函数相关属性


struct Numbers {
  int a;
  int b;
  int c; // c == a+b

Numbers n1 {1, 2, 3}; // Ok.
Numbers n2 {1, 2, 4}; // Error! 

In my use case, a, b, c are constant, if that matters (so const int may be used).

All attributes will appear many times in class/struct methods, so the goal is to cache the value a+b. Addition is used as an example, the dependency function may be more complex.