Damien Neil 82886da2b9 reflect/protoreflect: add {Message,List,Map}.IsValid
Various protoreflect methods can return an "empty, read-only" message,
list, or map value. Provide a method to test if a value is one of these.

Fixes golang/protobuf#966

Change-Id: I793d8426d6e2201755983c06f024412a7e09bc4c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/209018
Reviewed-by: Joe Tsai <joetsai@google.com>
2019-11-26 22:56:18 +00:00
..
2018-11-14 23:03:53 +00:00