Contemplating it a little bit more myself the past days, I came up with the following reasons:
Simplicity
The way it's written by merlyn is simpler to understand. It is in fact pseudo-code, not real code.

Already an object
The input may already consist of a reference or an object: no need to take a further reference in that case.

Alias / Copy On Write
Perl shouldn't have to copy the contents of $_. You could consider it a bug that it does so now. I'm pretty sure this innefficiency won't exist in Perl 6.

Liz

In reply to Re: ${Schwartzian transform} ? by liz
in thread ${Schwartzian transform} ? by liz

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