Yes, if the programmer knows the kind, he could just define the
appropriate parameter constant in a single place, and let that
definition propagate throughout the rest of the code in the usual way.
Also, there have been suggestions in the past to allow an optional
argument to selected_real_kind to specify the precision in bits rather
than decimal digits. That could be added at any time, in a backward
compatible way, once it is practically useful.
I realize in these discussions how many programmers do not appreciate
how well designed and how flexible the fortran kind system really is.
Compare to C for example, where each of these floating point kinds that
differ by one mantissa bit from each other is specified with some
obscure incantation of "short short long short long short...".
There are two modifications that might have been useful back when f90
first introduced this into the language. One is to have separate kind
values for different types, and the other would have been to have the
kind values be a type distinct from other integers. Either or both of
those things might have helped programmers eliminate coding errors. But
overall, it works very well in practice even as is, with almost
unlimited ability to expand and adapt in the future if/when these kinds
of floating point types become available.
$.02 -Ron Shepard