I was reading this C11's _Generic example on Wikipedia:
#define cbrt(X) _Generic((X), long double: cbrtl, \
default: cbrt, \
float: cbrtf)(X)
It seems pretty clear how to use it for functions with only one parameter, but I can't see a way to write functions with two (or more) generic parameters with this system. How could it be possible?
I would have tried some things if some compiler supported this feature but I could not find one either, so I was unable to find any idea on how to do that.
Obviously there is no "generic" rule for this, it really depends on the use case. But one typical use case would be to use the standard promotions to determine a common "supertype"
#define pow(X, Y) _Generic((X)+(Y), long double: powl, \
default: pow, \
float: powf)((X), (Y))
If X and Y wouldn't agree in type when calling this macro, the narrow one would automatically be promoted to the wider one.