G'day Bod,

"I've been looking at them more for curiosity than any need to use them."

They became experimental in 5.18.0 - see "perl5180delta". Of immediate interest to you, in that rather lengthy page, are probably these sections: "The smartmatch family of features are now experimental"; and, "New mechanism for experimental features".

Also look at the documentation for the pragmata: feature and experimental. The "Ordering matters" section in the latter holds the answer to your problem.

Here's a cutdown version of what you're doing: 

$ perl -E '
    use strict;
    use experimental "switch";
    use warnings;

    given (1) { say "Hello" }
'
given is experimental at -e line 6.
Hello

[download]

Taking the advice of the Ordering matters section, and the warning disappears: 

$ perl -E '
    use strict;
    use warnings;
    use experimental "switch";

    given (1) { say "Hello" }
'
Hello

[download]

— Ken

In reply to Re: Experimental warnings with given/when by kcott
in thread Experimental warnings with given/when by Bod

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