use strict;
use warnings;

use Test::More tests => 1;

my $val = 3.14159;
my $oldval = $val;

my $newval = do {
    use B;
    if ( not B::SVf_POK & B::svref_2object( \$val )->FLAGS or
         -1 != index $val, 'e' ) {
        $val = sprintf '%.4f', $val;
        $val =~ s/\.?0+$//
    }
    "$val"
};

is "$oldval", "$newval";