Howdy,
There's a minor incompatibility between the XS and PP versions of
Scalar::Util:
$ perl -MScalar::Util=looks_like_number -wle 'sub { &looks_like_number
&& print $_[0] }->(1)'
1
$ perl -MScalar::Util::PP=looks_like_number -wle 'sub
{ &looks_like_number && print $_[0] }->(1)'
Use of uninitialized value in print at -e line 1.
This is because the PP version shifts @_. Would be really swell if that
could be mended!