use List::Util qw[ first ];;
use List::MoreUtils qw[ first_value ];;

sub x{ say "<<<@_>>>"; return shift(); };;

$x = grep{ defined( x($_) ) } 1, undef,3;;
<<<1>>>
Use of uninitialized value in join or string at (eval 17) line 1, <STDIN> line 10.
<<<>>>
<<<3>>>

$x = first{ defined( x( $_ ) ) } 1, undef, 3;;
<<<1>>>

$x = first_value{ defined( x( $_ ) ) } 1, undef, 3;;
<<<1>>>