fix bug in consts code

gen.go

@@ -42,6 +42,9 @@ func doTemplate(w io.Writer, info interface{}, templ string) error {
 				}
 				return fmt.Sprintf("%d", val)
 			},
+			"Deref": func(sp *string) string {
+				return *sp
+			},
 		}).Parse(templ))
 
 	return t.Execute(w, info)
@@ -309,7 +312,7 @@ func emitCborMarshalStringField(w io.Writer, f Field) error {
 
 	if f.Const != nil {
 		return doTemplate(w, f, `
-	{{ MajorType "cw" "cbg.MajTextString" (print "len(" .Name ")") }}
+	{{ MajorType "cw" "cbg.MajTextString" (print "len(\""  (Deref .Const)  "\")") }}
 	if _, err := io.WriteString(w, string("{{ .Const }}")); err != nil {
 		return err
 	}

testing/roundtrip_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"math/rand"
 	"reflect"
@@ -388,4 +389,24 @@ func TestOmitEmpty(t *testing.T) {
 	testValueRoundtrip(t, &et, &recepticle)
 }
 
+func TestConstRoundtrip(t *testing.T) {
+	tcf := &TestConstField{
+		Thing: 16223,
+	}
+
+	buf := new(bytes.Buffer)
+	if err := tcf.MarshalCBOR(buf); err != nil {
+		t.Fatal(err)
+	}
+
+	fmt.Printf("%x\n", buf.Bytes())
+
+	var out TestConstField
+	if err := out.UnmarshalCBOR(buf); err != nil {
+		t.Fatal(err)
+	}
+
+	fmt.Println(out)
+}
+
 //TODO same for strings