It shouldn't do, unless your smart match operands also happen to be objects that override bitwise-or. (For example, Math::BigInt does.)

The match($a, $b) function really is saner though. And faster for that matter. (Though the real smartmatch operator beats each hands down!)

use v5.18;
use match::simple -all;
use Benchmark qw( cmpthese );

$::A = 3;
$::B = [1 .. 5];

cmpthese(-1, {
    'match' => q[ match($::A, $::B) ],
    'M'     => q[ $::A |M| $::B ],
    '~~'    => q[ no warnings 'experimental::smartmatch'; $::A ~~ $::B
+ ],
});

__END__
           Rate      M  match     ~~
M       11487/s     --   -69%   -99%
match   36540/s   218%     --   -97%
~~    1420284/s 12265%  3787%     --
[download]

Anybody willing to provide a patch for an XS implementation of match::simple::match() would be likely to have it accepted. ;-)