# concat with null argument data expression

# empty configs are not accepted by Kea
default-lease-time 1800;

# null left argument
class "null-left" {
    match concat("", suffix(option host-name, 3));
}

subclass "null-left" "com" { }

# null right argument
class "null-right" {
    match concat(suffix(option host-name, 3), substring("foobar", 0, 0));
}

subclass "null-right" "org" { }