Hi

I'm considering using the smart macht operator for argument constraints at the start of a sub.

I have to admit that ~~ still confuses me a lot

is the following code correct to check if

1. the argument is a simple scalar (that is no ref) 2. and element of the given set (here a b c)?

sub tst {
  %arg = @_;
  
  warn "wrong argument" unless
    "$arg{x}" ~~ [qw/a b c/] ;
}

[download]

so e.g. tst(x => "a"); is ok.

the explicit stringification (quotes) of "$arg{x}" is necessary to avoid tst(x => [qw/a b c/]); to be legal.

Any comments? Any better idioms for checking arguments?

Cheers Rolf

In reply to Smart matching for argument constraints by LanX

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