##
my $i = 5;
func($i+0, $i, ++$i, $i+0); # 5 6 6 6 for me.
# ^^^^ ^^
# rvalue lvalue
##
##
my $i = 5;
func($i, ++i, $i+2); # 6 6 8 for me.
^^
lvalue
my $i = 5;
func($i+0, ++i, $i+2); # 5 6 8 for me.
^^^^
rvalue