From 8e349ae2eadbeb031ba01e7d1a98d6c5130ba7e3 Mon Sep 17 00:00:00 2001
From: Lorenz Brun <lorenz@brun.one>
Date: Sat, 30 Nov 2024 01:05:11 +0100
Subject: [PATCH 2/2] expr: add Dynamic for family-dependent evaluation

This is used with a wrapper to implement easy dual-stack programming.
---
 expr/dynamic.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 expr/dynamic.go

diff --git a/expr/dynamic.go b/expr/dynamic.go
new file mode 100644
index 0000000..c7ee5e1
--- /dev/null
+++ b/expr/dynamic.go
@@ -0,0 +1,19 @@
+package expr
+
+// Dynamic can be used to return an expression based on the address family
+// the expression is used in.
+type Dynamic struct {
+	Expr func(fam uint8) Any
+}
+
+func (d *Dynamic) marshal(fam byte) ([]byte, error) {
+	return d.Expr(fam).marshal(fam)
+}
+
+func (d *Dynamic) marshalData(fam byte) ([]byte, error) {
+	return d.Expr(fam).marshalData(fam)
+}
+
+func (d *Dynamic) unmarshal(fam byte, data []byte) error {
+	return d.Expr(fam).unmarshal(fam, data)
+}
-- 
2.47.0