sub shuffleEm {
    ( shuffle 1 .. $range )[ 0 .. $uSize ];
}

##</code><code>##

cmpthese( -1, {
    grepGen  => sub{ @grep  = grepGen();  },
    mapGen   => sub{ @map   = mapGen();   },
    smartGen => sub{ @smart = smartGen(); },
    shuffleEm=> sub{ @shuffled = shuffleEm() },
} );

##</code><code>##

C:\test>junk
             Rate   grepGen    mapGen  smartGen shuffleEm
grepGen    35.3/s        --      -51%      -97%     -100%
mapGen     72.6/s      106%        --      -94%     -100%
smartGen   1250/s     3439%     1621%        --      -95%
shuffleEm 26859/s    75977%    36902%     2049%        --