I ran across the following line of code in Class:Struct and was curious about it. I did some benchmarks and, depending on what and how it was used, it was anywhere from 10-15% faster for large iterations than what I would have used.


my $isa = do {
  no strict 'refs';
  \@{$class . '::ISA'};
};

I would have used the following:


my $isa;
{ no strict "refs";
  $isa = \@{$class . '::ISA'};
}

Now, I understand *what* is happening with Damien's code, but not *why* it's so much faster. I'm thinking it has something to do with the separation of the declaration and definition of the $isa variable, but I don't see why.

Any ideas?

Harley J Pig

In reply to Hair Splitting? by harleypig

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