As with all those C++ base types, unfortunately they are giving you
only rough size guarantees. For Lumiera, I defined short hand names
some time ago, notably because the explicit long X and short X qualifiers
do not work with ''constructor syntax'' for direct conversions.
But I choose the name `f128` at that time -- which might raise ill-guided
expectations, since the `long double` is not that long on relevant linux 64bit
platforms; it can just hold 64bit of mantissa at least however.
As replacement, I'll use `lflo` now, because it has also 4 letters,
looks somewhat weird (and thus catches attention) and points into the
right direction. I considered `lfloat` as alternative, but that looks
too much like `float`, visually...