PBP is not a book to be followed without thinking. constant has its uses (the main feature is compile time evaluation and inlining), Readonly has other uses. See e.g. What is the difference between the constant construct in Perl and the Readonly construct in Perl? for an old discussion on the same topic.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re: Readonly vs ReadonlyX by choroba
in thread Readonly vs ReadonlyX by rlauer

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