use strict;
use warnings;
use Data::Types ':whole';

for (0, -1, 17, 1.25, 1e6, 062, 0xDEADBEEF, 4.0, 5.)
{
    printf "%10s: %s\n", $_, is_whole($_) ? 'yes' : 'no';
}

##</code><code>##

23:51 >perl 989_SoPW.pl
         0: yes
        -1: no
        17: yes
      1.25: no
   1000000: yes
        50: yes
3735928559: yes
         4: yes
         5: yes

23:51 >

##</code><code>##

/^\+?\d+$/
  ^