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Idiom #270 Test for quiet or signaling NaN

Given a floating point number r1 classify it as follows:
If it is a signaling NaN, print "This is a signaling NaN."
If it is a quiet NaN, print "This s a quiet NaN."
If it is not a NaN, print "This is a number."

if (r1.isNaN) {
  print("This is a quiet NaN.");
} else {
  print("This is a number.");
}
use, intrinsic:: ieee_arithmetic
  character (len=:), allocatable :: msg
  if (ieee_support_nan(r1)) then
     if (ieee_class(r1) == ieee_quiet_nan) then
        msg = "This s a quiet NaN."
     else if (ieee_class(r1) == ieee_signaling_nan) then
        msg = "This is a signaling NaN."
     else
        msg = "This is a number."
     end if
  else
     msg = "NaNs are not supported."
  end if
  write (*,'(A)') msg
uses sysutils;
  if r1.IsNan then
  begin
   if (TDoubleRec(r1).Data and $4000000000000000) = $4000000000000000 then
     writeln('This is a quiet NaN')
   else
     writeln('This is a signalling NaN');
  end
  else
    writeln('This is a number: ',r1);
import math
if math.isnan(r1):
    print('This is a quiet NaN.')
else:
    print('This is a number.')

New implementation...
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tkoenig