\b works for me, even with Hebrew: 
#! /usr/bin/perl
use warnings;
use strict;
use utf8;
my $string = 'שָׁלוֹם';
print $string =~ /\bש/, "\n";

(I had to use <pre> instead of <code> to make UTF-8 work.)

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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In reply to Re^3: \b in Unicode regex by choroba
in thread \b in Unicode regex by Arik123

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