Adds support for decoding Timestamp to Time (#183)

ion/unmarshal.go

@@ -506,13 +506,20 @@ func (d *Decoder) decodeTimestampTo(v reflect.Value) error {
 
 	switch v.Kind() {
 	case reflect.Struct:
-		if v.Type() == timestampType {
+		switch v.Type() {
+		case timestampType:
 			if val != nil {
 				v.Set(reflect.ValueOf(*val))
 			}
 			return d.attachAnnotations(v)
+		case nativeTimeType:
+			if val != nil {
+				v.Set(reflect.ValueOf((*val).dateTime))
+			}
+			return d.attachAnnotations(v)
+		default:
+			return d.decodeToStructWithAnnotation(v, timestampType.Kind())
 		}
-		return d.decodeToStructWithAnnotation(v, timestampType.Kind())
 
 	case reflect.Interface:
 		if v.NumMethod() == 0 {

ion/unmarshal_test.go

@@ -422,10 +422,19 @@ func TestDecodeTimestampTo(t *testing.T) {
 		t.Run(str, func(t *testing.T) {
 			d := NewDecoder(NewReaderString(str))
 
-			var val Timestamp
-			require.NoError(t, d.DecodeTo(&val))
+			var timestampVal Timestamp
+			require.NoError(t, d.DecodeTo(&timestampVal))
 
-			assert.True(t, val.Equal(eval), "expected %v, got %v", eval, val)
+			assert.True(t, timestampVal.Equal(eval), "expected %v, got %v", eval, timestampVal)
+		})
+
+		t.Run(str, func(t *testing.T) {
+			d := NewDecoder(NewReaderString(str))
+
+			var timeVal time.Time
+			require.NoError(t, d.DecodeTo(&timeVal))
+
+			assert.True(t, timeVal.Equal(eval.dateTime), "expected %v, got %v", eval.dateTime, timeVal)
 		})
 	}
 	test("null", Timestamp{})