We've been discussing a paper on this (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2466.pdf) at recent meetings and it's been fairly well-received each time, but not adopted for C2x as of yet.
The generic heterogeneous operations also avoid the identifier blowup. The only real argument against them that I see is that they are not easily implementable in C itself, but that's nothing new for the standard library (and should be a non-goal, in my not-a-committee-member opinion).
Obviously, I'm not privy to the committee discussions around this, so there may be good reasons for the choice, but it worries me a lot to see that document.
Hi Stephen, thank you for bringing this to our attention. David Svoboda and I are now working to revise the proposal to add a supplemental proposal to support operations on heterogeneous types. We are leaning toward proposing a three-argument syntax, where the 3rd argument specifies the return type, like:
ckd_add(a, b, T)
ckd_add(a, b)
>once you have the heterogeneous operations, is there any reason to keep the others around
The two-argument form is shorter, but perhaps that isn't a strong enough reason to keep it. Also, requiring a redundant 3rd argument can provide an opportunity for mistakes to happen if it gets out of sync with the type of first two arguments.
As for the non-generic functions (e.g., ckd_int_add, ckd_ulong_add, etc.), we are considering removing them in favor of having only the generic function-like macros.