Func arg

Question

what if i want to use default value of first arg?
for example
int sum(a=5,b=3);
main()
{
sum(xxx,5);
}
what should i write(where xxx) if i forgot default value of a?

Answer 1

honestly, you should just add that in a comment
or maybe check to make sure the default value is really necessary and that the order they are written makes sense