Support pointers of wrapping structs

convert.go

@@ -8,9 +8,11 @@ import (
 	"time"
 )
 
-const maxUint = ^uint(0)
-const maxInt = int(maxUint >> 1)
-const minInt = -maxInt - 1
+const (
+	maxUint = ^uint(0)
+	maxInt  = int(maxUint >> 1)
+	minInt  = -maxInt - 1
+)
 
 // underlyingNumberType gets the underlying type that can be converted to Int2, Int4, Int8, Float4, or Float8
 func underlyingNumberType(val interface{}) (interface{}, bool) {
@@ -432,6 +434,23 @@ func GetAssignToDstType(dst interface{}) (interface{}, bool) {
 		}
 	}
 
+	if dstVal.Kind() == reflect.Struct {
+		if dstVal.Type().NumField() == 1 && dstVal.Type().Field(0).Anonymous {
+			dstPtr = dstVal.Field(0).Addr()
+			nested := dstVal.Type().Field(0).Type
+			if nested.Kind() == reflect.Array {
+				if baseElemType, ok := kindTypes[nested.Elem().Kind()]; ok {
+					baseArrayType := reflect.PtrTo(reflect.ArrayOf(nested.Len(), baseElemType))
+					nextDst := dstPtr.Convert(baseArrayType)
+					return nextDst.Interface(), dstPtr.Type() != nextDst.Type()
+				}
+			}
+			if _, ok := kindTypes[nested.Kind()]; ok && dstPtr.CanInterface() {
+				return dstPtr.Interface(), true
+			}
+		}
+	}
+
 	return nil, false
 }
 

uuid_test.go

@@ -16,6 +16,10 @@ func TestUUIDTranscode(t *testing.T) {
 	})
 }
 
+type SomeUUIDWrapper struct {
+	SomeUUIDType
+}
+
 type SomeUUIDType [16]byte
 
 func TestUUIDSet(t *testing.T) {
@@ -127,6 +131,20 @@ func TestUUIDAssignTo(t *testing.T) {
 		}
 	}
 
+	{
+		src := pgtype.UUID{Bytes: [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}, Status: pgtype.Present}
+		var dst SomeUUIDWrapper
+		expected := [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+
+		err := src.AssignTo(&dst)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if dst.SomeUUIDType != expected {
+			t.Errorf("expected %v to assign %v, but result was %v", src, expected, dst)
+		}
+	}
 }
 
 func TestUUID_MarshalJSON(t *testing.T) {