! Aware to Perl: Use of "$$<digit>" to mean "${$}<digit>" is deprecated

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Use of "$$<digit>" to mean "${$}<digit>" is deprecated

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Use of "$$" to mean "${$}" is deprecated

(D) Perl versions before 5.004 misinterpreted any type marker followed by ``$'' and a digit. For example, ``$$0'' was incorrectly taken to mean ``${$}0'' instead of ``${$0}''. This bug is (mostly) fixed in Perl 5.004.

However, the developers of Perl 5.004 could not fix this bug completely, because at least two widely-used modules depend on the old meaning of ``$$0'' in a string. So Perl 5.004 still interprets ``$$<digit>'' in the old (broken) way inside strings; but it generates this message as a warning. And in Perl 5.005, this special treatment will cease.

Source: what's new for perl5.004
what's new for perl5.004
Copyright: Larry Wall, et al.

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