As I already said, accepting undef as valid argument is such a special and rare case that it should be covered by another approach. (see footnotes in OP)

Here using ternaries is far more explicit and shows that a special argument undef is accepted.

my $a = exists $arg{a} ? $arg{a} : 'else case';

But I agree that it's better to name the error die('Undefined argument!') instead of 'Missing argument' to avoid such misunderstandings.

Cheers Rolf

In reply to Re^2: RFC: New style for argument check in subs by LanX
in thread RFC: New style for argument check in subs by LanX

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