#!/usr/bin/perl -w

package mypackage;
use Data::Alias;

our $local_varnames = 'qw( $a $b $c )';
our $len_local_varnames;

{
# prefer-> $len_local_varnames=  wantarray (eval"($local_varnames)"); OR
#    $len_local_varnames= 0+eval"($local_varnames)";

    $len_local_varname = eval "local @_=($local_varnames)";

}

printf "len_local_varnames=%d\n",$len_local_varnames;