Hi- As far as I can tell, the ISO C towupper will probably work correctly on UCS-4 characters created by Gnulib functions like u32_conv_from_enc. But, it seems that it isn't guaranteed to do so, since wint_t is not required to be UCS-4. (I don't have a counterexample: I'm just going from what I've read.)
If that is true, then it would be neat to have u32_toupper and u32_tolower functions. Thanks, Mike Gran
