erlang: Add a more detailed spec for thrift_protocol:read

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@990976 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/erl/include/thrift_protocol.hrl b/lib/erl/include/thrift_protocol.hrl
index 201bade..f85f455 100644
--- a/lib/erl/include/thrift_protocol.hrl
+++ b/lib/erl/include/thrift_protocol.hrl
@@ -57,6 +57,10 @@
                         | double
                         | string
                         .
+-type tprot_cont_tag() :: {list, _Type}
+                        | {map, _KType, _VType}
+                        | {set, _Type}
+                        .
 
 
 -endif.