Programming Perl, 4th Edition

if

use if CONDITION, MODULE => IMPORTS;

use if $^O =~ /MSWin/, "Win32::File";

use if $^V >= 5.010, parent => qw(Mojolicious::UserAgent);
use if $^V <  5.010, base   => qw(LWP::UserAgent);

The if pragma controls the loading of a module based on some condition. This pragma doesn’t handle loading modules with a minimum version. Specify an import list after the module name.