One other thing that would be great that sometimes people use the preprocessor for is having the names variables/enums as runtime strings. Like, if you have an enum and a function to get the string representation for debug purposes (i.e. the name of the enum as represented inside the source code):
you can use various preprocessor tricks to implement getEnumName such that you don't have to change it when adding more cases to the enum. This would be much better implemented with some compiler intrinsic/operator like `nameof(val)` that returned a string. C# does something similar with its `nameof`.
Hey, even an article written by Walter, that's a fun coincidence! :)
This is slightly different than the form I've seen it, but same idea: in the version I've seen, you have a special file that's like "enums.txt" with contents like (warning, not tested):
X(red)
X(green)
X(blue)
and then you write:
typedef enum {
#define X(x) x
#include "enums.txt"
#undef X
} color;
const char* getColorName(color c) {
switch (c) {
#define X(x) case x: return #x;
#include "enums.txt"
#undef X
}
}
Same idea, just using an #include instead of listing them in a macro. Thinking about it, it's sort-of a compile time "visitor pattern".
