This distribution contains code from L<CryptX> and L<LibTomCrypt|https://www.libtom.net/LibTomCrypt/>,
bundled according to their own licensing terms (which are also permissive).
+=begin markdown
+
+[![Linux](https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/linux.yml/badge.svg)](https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/linux.yml)
+[![macOS](https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/macos.yml/badge.svg)](https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/macos.yml)
+[![Windows](https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/windows.yml/badge.svg)](https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/windows.yml)
+
+=end markdown
+
+=begin HTML
+
+<a title="Linux" href="https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/linux.yml"><img src="https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/linux.yml/badge.svg"></a>
+<a title="macOS" href="https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/macos.yml"><img src="https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/macos.yml/badge.svg"></a>
+<a title="Windows" href="https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/windows.yml"><img src="https://github.com/chazmcgarvey/File-KDBX-XS/actions/workflows/windows.yml/badge.svg"></a>
+
+=end HTML
+
+=func CowREFCNT
+
+Get the copy-on-write (COW) reference count of a scalar, or C<undef> if the perl does not support scalar COW
+or if the scalar is not COW.
+
+See also L<B::COW/"cowrefcnt( PV )">.
+
+=for Pod::Coverage kdf_aes_transform_half
+
=cut