utx::make_unsigned_t is used to get an unsigned integral type from a known ingral type.
That is, it gets utx::ux32 from utx::ix32, utx::ux32; gets utx::u32from utx::i32, utx::u32; ..., etc.
utx::make_unsigned_t never gets utx::overflow_type from an integral type, although it has such as check.
However, utx::make_unsigned_t gets utx::overflow_type, if the source type is not integral type.
utx::make_unsigned_t related - utx::make_unsigned_basic_t, utx::make_unsigned_uct_t
using target_type = utx::make_unsigned_t<source_inegral_type>;