Summary: B::COW additional B helpers to check COW status

Description:
B::COW provides some naive additional B helpers to check the COW status of
one SvPV.

COW or Copy On Write introduction
A COWed SvPV is sharing its string (the PV) with other SvPVs. It's a
(kind of) Read Only C string, that would be Copied On Write (COW).

More than one SV can share the same PV, but when one PV need to alter
it, it would perform a copy of it, decrease the COWREFCNT counter.

URL: https://metacpan.org/release/B-COW
License: GPLv1+ or Artistic

Maintainer: tv