https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125624
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- We don't support them, they just happen to compile and produce *some* answer, without any explicit effort from us or any intentional support. And for float16_t it also produces *some* answer, which happens to be always NaN. But the new implementation of std::generate_canonical in GCC 16 is known to not work at all for float16_t. Your concepts which check that the distribution can be constructed do *not* mean the distribution works with those types.
