My most frequent uses of if seem to be:

# Loading either "mro" or "MRO::Compat" depending
# on Perl version...
#
use if $] >= 5.010, 'mro';
use if $] <  5.010, 'MRO::Compat';

# Load UNIVERSAL::DOES for Perl prior to 5.10.
#
use if $] < 5.010, 'UNIVERSAL::DOES';

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It's pretty easy to emulate it anyway:

# Loading either "mro" or "MRO::Compat" depending
# on Perl version...
#
BEGIN {
  if ($] >= 5.010) { require mro;         mro->import }
  else             { require MRO::Compat; MRO::Compat->import }
};

# Load UNIVERSAL::DOES for Perl prior to 5.10.
#
BEGIN {
  require 'UNIVERSAL::DOES' if $] < 5.010;
};

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CPAN also has unless.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

In reply to Re: How do you use the if pragma? by tobyink
in thread How do you use the if pragma? by qazwart

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