Well for example, consider the following code: 
for my $i (1..2) {
    print "match\n" if "x1" =~ /x${print "doing arg\n"; \1}/o;
}

[download]
On threaded perls it prints "doing arg" twice; on unthreaded, once.

Dave.

In reply to Re^15: Reusing a complex regexp in multiple spots, escaping the regexp by dave_the_m
in thread Reusing a complex regexp in multiple spots, escaping the regexp by ecm

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