generic way to print out variable name in c++

Question

given a class

struct {
  int a1;
  bool a2;
  ...
  char* a500;
  ...
  char a10000;      
}

I want to print or stream out

Answer 1

The watch macro is one of the most useful tricks ever.

#define watch(x) cout << (#x) << " is " << (x) << endl

If you’re debugging your code, watch(variable); will print the name of the variable and its value. (It’s possible because it's built during preprocessing time.)