I believe 

my $is_valid = utf8::decode($_);

[download]
is cheaper than 
use Encode qw( decode );
my $is_valid = eval '$_ = decode("utf-8", $_, FB_CROAK); 1';

[download]

It's definitely simpler (and you don't even need to load any modules!)

Note that "utf8" is not the same thing "utf-8". "utf8" is the name of Perl's internal encoding. It differs from "utf-8". You definitely want to use "utf-8" when validating (if not always).

I also fixed the bug where decoding the string "0" would be considered a validation error.

In reply to Re^2: unicode normalization layer by ikegami
in thread unicode normalization layer by DrWhy

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