.. contents ::
+Nanopb-0.3.2 (2015-01-24)
+=========================
+
+Add support for OneOfs
+----------------------
+**Rationale:** Previously nanopb did not support the *oneof* construct in
+*.proto* files. Those fields were generated as regular *optional* fields.
+
+**Changes:** OneOfs are now generated as C unions. Callback fields are not
+supported inside oneof and generator gives an error.
+
+**Required actions:** The generator option *no_unions* can be used to restore old
+behaviour and to allow callbacks to be used. To use unions, one change is
+needed: use *which_xxxx* field to detect which field is present, instead
+of *has_xxxx*. Compare the value against *MyStruct_myfield_tag*.
+
+**Error indications:** Generator error: "Callback fields inside of oneof are
+not supported". Compiler error: "Message" has no member named "has_xxxx".
+
Nanopb-0.3.0 (2014-08-26)
=========================
as *void\**. This allowed passing of any data, but made it unnecessarily
complex to return a pointer from callback.
-**Changes:** The callback function parameter was changed to *void\**.
+**Changes:** The callback function parameter was changed to *void\*\**.
**Required actions:** You can continue using the old callback style by
defining *PB_OLD_CALLBACK_STYLE*. Recommended action is to:
- * Change the callback signatures to contain *void\** for decoders and
+ * Change the callback signatures to contain *void\*\** for decoders and
*void \* const \** for encoders.
* Change the callback function body to use *\*arg* instead of *arg*.