Not quite.

$ perl -wle'print 0 + sub { my @v; !!@v }->()'
0

$ perl -wle'print 0 + sub { my @v; @v ? 1 : "" }->()'
Argument "" isn't numeric in addition (+) at -e line 1.
0
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And it doesn't return zero for false either.

$ perl -wle'print "" . sub { my @v; !!@v }->()'


$ perl -wle'print "" . sub { my @v; @v ? 1 : 0 }->()'
0
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False is actually dualvar(0, '')