Is this elegant?

my @fields = map {s/\?'/'/g; $_} split /\+|(?<!\?)'/, $line;
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The split is on plus or apostrophes not preceded by a question mark. The map turns "?'" into just "'".

Update: It's probably clearer (and thus better) to say

my @fields = split /\+|(?<!\?)'/, $line;
s/\?'/'/g for @fields;
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