How to catch NaNs with gnat3.14p

["Alexander Boucke" <alexb@lufmech.rwth-aachen.de>]

Hello!

One of the announced features of gnat3.14p is the ability to raise contraint
error, when NaN or Inf occures. But how to do it? I was not able to find
something about this in the documentation. And the following program just
behaves as with gnat3.13p:

with ada.text_io; use ada.text_io;
procedure nan is
   float1, float2 : float := 0.0;
   a_nan : float;
begin
   a_nan := float1/float2;
   if not a_nan'valid then
      put_line("A NaN occured " & a_nan'img);
   else
      put_line(a_nan'img);
   end if;
end nan;

compiling (gnatmake -gnato nan) yields the output:
> ./nan
A NaN occured NaN********
>

Did I miss something?

Regards,
Alexander