diff --git a/CHANGELOG.md b/CHANGELOG.md
index 170472c0..8813f116 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Change Log
 
-## [0.5.0-pre]
+## [0.5.0]
 - New schema type aliases: int8, uint8, int16, uint16, int32, uint32,
   int64, uint64, float32, float64.
 - Low-level: access multiple user frames in builder via handles.
diff --git a/README.md b/README.md
index a0390bbe..ec28cb07 100644
--- a/README.md
+++ b/README.md
@@ -3,12 +3,6 @@ Windows: [![Windows Build Status](https://ci.appveyor.com/api/projects/status/gi
 
 # FlatCC FlatBuffers in C for C
 
-_NOTE: ongoing work towards version 0.5.0 features might cause minor
-breakage. For full backwards compatibility use the v0.4.3 tag.
-If you work with JSON parsing, you may want to patch v0.4.3 with commit
-[1cb266](https://github.com/dvidelabs/flatcc/commit/1cb2664dcd104b2051d410955018cb255370302e)
-which only affects code generation, not the runtime library._
-
 `flatcc` has no external dependencies except for build and compiler
 tools, and the C runtime library. With concurrent Ninja builds, a small
 client project can build flatcc with libraries, generate schema code,
@@ -234,21 +228,21 @@ fi
 
 ## Status
 
-v0.5.0 is in development on master branch primarily to reach feature
-parity with Googles flatc schema parser as of end 2017. These new
-features are union vectors and mixed type unions that can include
-tables, structs and strings, and type aliases for int8, uint8, int16,
-uint16, int32, uint32, int64, uint64, float32, float64 types in the
-schema. Support for base64(url) JSON encoded [ubyte] vectors has been
-added which will also be added to Googles flatc tool in a future
-release. In addition the following changes have been added: Runtime
-builder library support for `aligned_alloc/free`. Handling of unions is
-slightly incompatible with previous releases as covered in the
-documentation. v0.5.0 fixes a bug that could cause a JSON parser to
-reject some valid symbols for some schemas and also fixes a non-critical
-JSON scoping issue with symbolic union names and a bug verifying buffers
-with a struct as root. Low-level custom frame support has been improved
-in the builder library which is useful for complex parsing scenarios.
+Release 0.5.0 aims to reach feature parity with C++ FlatBuffers as of
+end 2017. These new features are union vectors and mixed type unions
+that can include tables, structs and strings, and type aliases for int8,
+uint8, int16, uint16, int32, uint32, int64, uint64, float32, float64
+types in the schema. Support for base64(url) JSON encoded [ubyte]
+vectors has been added which will also be added to Googles flatc tool in
+a future release. In addition the following changes have been added:
+Runtime builder library support for `aligned_alloc/free`. Handling of
+unions is slightly incompatible with previous releases as covered in the
+documentation and the changelog. v0.5.0 fixes a bug that could cause a
+JSON parser to reject some valid symbols for some schemas and also fixes
+a non-critical JSON scoping issue with symbolic union names and a bug
+verifying buffers with a struct as root. Low-level custom frame support
+has been improved in the builder library which is useful for complex
+parsing scenarios.
 
 
 Main features supported as of 0.5.0
@@ -271,9 +265,9 @@ Main features supported as of 0.5.0
 - flexible configuration of malloc alternatives and runtime
   aligned_alloc/free support in builder library.
 - feature parity with C++ FlatBuffers schema features added in 2017
-  union vectors and mixed type unions of strings, structs, and tables.
-- base64(url) encoded binary data in JSON, soon to also be supported by
-  Googles flatc JSON parser.
+  adding support for union vectors and mixed type unions of strings,
+  structs, and tables, and type aliases for uint8, ..., float64.
+- base64(url) encoded binary data in JSON.
 
 
 Supported platforms (as covered by CI release tests on ci-more branch):
diff --git a/include/flatcc/flatcc_version.h b/include/flatcc/flatcc_version.h
index 25ae3634..cd644a72 100644
--- a/include/flatcc/flatcc_version.h
+++ b/include/flatcc/flatcc_version.h
@@ -1,6 +1,6 @@
-#define FLATCC_VERSION_TEXT "0.5.0-pre"
+#define FLATCC_VERSION_TEXT "0.5.0"
 #define FLATCC_VERSION_MAJOR 0
 #define FLATCC_VERSION_MINOR 5
 #define FLATCC_VERSION_PATCH 0
 /* 1 or 0 */
-#define FLATCC_VERSION_RELEASED 0
+#define FLATCC_VERSION_RELEASED 1
diff --git a/include/flatcc/reflection/flatbuffers_common_builder.h b/include/flatcc/reflection/flatbuffers_common_builder.h
index 08cd4185..d8c94afa 100644
--- a/include/flatcc/reflection/flatbuffers_common_builder.h
+++ b/include/flatcc/reflection/flatbuffers_common_builder.h
@@ -1,7 +1,7 @@
 #ifndef FLATBUFFERS_COMMON_BUILDER_H
 #define FLATBUFFERS_COMMON_BUILDER_H
 
-/* Generated by flatcc 0.4.3 FlatBuffers schema compiler for C by dvide.com */
+/* Generated by flatcc 0.5.0 FlatBuffers schema compiler for C by dvide.com */
 
 /* Common FlatBuffers build functionality for C. */
 
@@ -13,6 +13,8 @@
 typedef flatcc_builder_t flatbuffers_builder_t;
 typedef flatcc_builder_ref_t flatbuffers_ref_t;
 typedef flatcc_builder_ref_t flatbuffers_vec_ref_t;
+typedef flatcc_builder_union_ref_t flatbuffers_union_ref_t;
+typedef flatcc_builder_union_vec_ref_t flatbuffers_union_vec_ref_t;
 /* integer return code (ref and ptr always fail on 0) */
 #define flatbuffers_failed(x) ((x) < 0)
 typedef flatbuffers_ref_t flatbuffers_root_t;
@@ -85,7 +87,15 @@ static inline NS ## buffer_ref_t N ## _create_as_typed_root(NS ## builder_t *B _
   N ## _create(B __ ## N ## _call_args), A, 0); }\
 static inline NS ## buffer_ref_t N ## _create_as_typed_root_with_size(NS ## builder_t *B __ ## N ## _formal_args)\
 { return flatcc_builder_create_buffer(B, TFID, 0,\
-  N ## _create(B __ ## N ## _call_args), A, flatcc_builder_with_size); }
+  N ## _create(B __ ## N ## _call_args), A, flatcc_builder_with_size); }\
+static inline NS ## buffer_ref_t N ## _clone_as_root(NS ## builder_t *B, N ## _struct_t p)\
+{ return flatcc_builder_create_buffer(B, FID, 0, N ## _clone(B, p), A, 0); }\
+static inline NS ## buffer_ref_t N ## _clone_as_root_with_size(NS ## builder_t *B, N ## _struct_t p)\
+{ return flatcc_builder_create_buffer(B, FID, 0, N ## _clone(B, p), A, flatcc_builder_with_size); }\
+static inline NS ## buffer_ref_t N ## _clone_as_typed_root(NS ## builder_t *B, N ## _struct_t p)\
+{ return flatcc_builder_create_buffer(B, TFID, 0, N ## _clone(B, p), A, 0); }\
+static inline NS ## buffer_ref_t N ## _clone_as_typed_root_with_size(NS ## builder_t *B, N ## _struct_t p)\
+{ return flatcc_builder_create_buffer(B, TFID, 0, N ## _clone(B, p), A, flatcc_builder_with_size); }
 
 #define __flatbuffers_build_nested_table_root(NS, N, TN, FID, TFID)\
 static inline int N ## _start_as_root(NS ## builder_t *B)\
@@ -169,6 +179,29 @@ static inline N ## _vec_ref_t N ## _vec_slice(NS ## builder_t *B, N ##_vec_t vec
   return flatcc_builder_create_vector(B, N ## __const_ptr_add(vec, index), len, S, A, FLATBUFFERS_COUNT_MAX(S)); }\
 __flatbuffers_build_vector_ops(NS, N ## _vec, N, N, T)
 
+#define __flatbuffers_build_union_vector_ops(NS, V, N, TN)\
+static inline TN ## _union_ref_t *V ## _extend(NS ## builder_t *B, size_t len)\
+{ return flatcc_builder_extend_union_vector(B, len); }\
+static inline TN ## _union_ref_t *V ## _append(NS ## builder_t *B, const TN ## _union_ref_t *data, size_t len)\
+{ return flatcc_builder_append_union_vector(B, data, len); }\
+static inline int V ## _truncate(NS ## builder_t *B, size_t len)\
+{ return flatcc_builder_truncate_union_vector(B, len); }\
+static inline TN ## _union_ref_t *V ## _edit(NS ## builder_t *B)\
+{ return flatcc_builder_union_vector_edit(B); }\
+static inline size_t V ## _reserved_len(NS ## builder_t *B)\
+{ return flatcc_builder_union_vector_count(B); }\
+static inline TN ## _union_ref_t *V ## _push(NS ## builder_t *B, const TN ## _union_ref_t ref)\
+{ return flatcc_builder_union_vector_push(B, ref); }
+
+#define __flatbuffers_build_union_vector(NS, N)\
+static inline int N ## _vec_start(NS ## builder_t *B)\
+{ return flatcc_builder_start_union_vector(B); }\
+static inline N ## _union_vec_ref_t N ## _vec_end(NS ## builder_t *B)\
+{ return flatcc_builder_end_union_vector(B); }\
+static inline N ## _union_vec_ref_t N ## _vec_create(NS ## builder_t *B, const N ## _union_ref_t *data, size_t len)\
+{ return flatcc_builder_create_union_vector(B, data, len); }\
+__flatbuffers_build_union_vector_ops(NS, N ## _vec, N, N)
+
 #define __flatbuffers_build_string_vector_ops(NS, N)\
 static inline int N ## _push_start(NS ## builder_t *B)\
 { return NS ## string_start(B); }\
@@ -279,7 +312,7 @@ static inline N ## _t *N ##_to_pe(N ## _t *p)\
 { if (!NS ## is_native_pe()) { N ## _copy_to_pe(p, p); }; return p; }\
 static inline N ## _t *N ##_from_pe(N ## _t *p)\
 { if (!NS ## is_native_pe()) { N ## _copy_from_pe(p, p); }; return p; }\
-static inline N ## _t *N ## _clear(N ## _t *p) { return memset(p, 0, N ## __size()); }
+static inline N ## _t *N ## _clear(N ## _t *p) { return (N ## _t *)memset(p, 0, N ## __size()); }
 
 /* Depends on generated copy/assign_to/from_pe functions, and the type. */
 #define __flatbuffers_build_struct(NS, N, S, A, FID, TFID)\
@@ -288,13 +321,16 @@ typedef NS ## ref_t N ## _ref_t;\
 static inline N ## _t *N ## _start(NS ## builder_t *B)\
 { return (N ## _t *)flatcc_builder_start_struct(B, S, A); }\
 static inline N ## _ref_t N ## _end(NS ## builder_t *B)\
-{ if (!NS ## is_native_pe()) { N ## _to_pe(flatcc_builder_struct_edit(B)); }\
+{ if (!NS ## is_native_pe()) { N ## _to_pe((N ## _t *)flatcc_builder_struct_edit(B)); }\
   return flatcc_builder_end_struct(B); }\
 static inline N ## _ref_t N ## _end_pe(NS ## builder_t *B)\
 { return flatcc_builder_end_struct(B); }\
 static inline N ## _ref_t N ## _create(NS ## builder_t *B __ ## N ## _formal_args)\
 { N ## _t *_p = N ## _start(B); if (!_p) return 0; N ##_assign_to_pe(_p __ ## N ## _call_args);\
   return N ## _end_pe(B); }\
+static inline N ## _ref_t N ## _clone(NS ## builder_t *B, N ## _struct_t p)\
+{ N ## _t *_p = N ## _start(B); if (!_p) return 0;\
+  N ## _copy(_p, p); return N ##_end_pe(B); }\
 __flatbuffers_build_vector(NS, N, N ## _t, S, A)\
 __flatbuffers_build_struct_root(NS, N, A, FID, TFID)
 
@@ -321,24 +357,52 @@ static inline TN ## _ref_t N ## _create(NS ## builder_t *B __ ## TN ##_formal_ar
 
 #define __flatbuffers_build_union_field(ID, NS, N, TN)\
 static inline int N ## _add(NS ## builder_t *B, TN ## _union_ref_t uref)\
-{ NS ## ref_t *_p; TN ## _union_type_t *_pt; if (uref.type == TN ## _NONE) return 0; if (uref._member == 0) return -1;\
-  if (!(_pt = (TN ## _union_type_t *)flatcc_builder_table_add(B, ID - 1, sizeof(*_pt), sizeof(_pt))) ||\
-  !(_p = flatcc_builder_table_add_offset(B, ID))) return -1; *_pt = uref.type; *_p = uref._member; return 0; }\
+{ NS ## ref_t *_p; TN ## _union_type_t *_pt; if (uref.type == TN ## _NONE) return 0; if (uref.member == 0) return -1;\
+  if (!(_pt = (TN ## _union_type_t *)flatcc_builder_table_add(B, ID - 1, sizeof(*_pt), sizeof(*_pt))) ||\
+  !(_p = flatcc_builder_table_add_offset(B, ID))) return -1; *_pt = uref.type; *_p = uref.member; return 0; }\
 static inline int N ## _add_type(NS ## builder_t *B, TN ## _union_type_t type)\
 { TN ## _union_type_t *_pt; if (type == TN ## _NONE) return 0; return (_pt = (TN ## _union_type_t *)flatcc_builder_table_add(B, ID - 1,\
   sizeof(*_pt), sizeof(*_pt))) ? ((*_pt = type), 0) : -1; }\
 static inline int N ## _add_member(NS ## builder_t *B, TN ## _union_ref_t uref)\
 { NS ## ref_t *p; if (uref.type == TN ## _NONE) return 0; return (p = flatcc_builder_table_add_offset(B, ID)) ?\
-  ((*p = uref._member), 0) : -1; }
+  ((*p = uref.member), 0) : -1; }
 
 /* M is the union member name and T is its type, i.e. the qualified name. */
-#define __flatbuffers_build_union_member_field(NS, N, NU, M, T)\
+#define __flatbuffers_build_union_table_member_field(NS, N, NU, M, T)\
 static inline int N ## _ ## M ## _add(NS ## builder_t *B, T ## _ref_t ref)\
 { return N ## _add(B, NU ## _as_ ## M (ref)); }\
 static inline int N ## _ ## M ## _start(NS ## builder_t *B)\
 { return T ## _start(B); }\
 static inline int N ## _ ## M ## _end(NS ## builder_t *B)\
-{ return N ## _ ## M ## _add(B, T ## _end(B)); }
+{ T ## _ref_t ref = T ## _end(B);\
+  return ref ? N ## _ ## M ## _add(B, ref) : -1; }\
+static inline int N ## _ ## M ## _create(NS ## builder_t *B __ ## T ##_formal_args)\
+{ T ## _ref_t ref = T ## _create(B __ ## T ## _call_args);\
+  return ref ? N ## _add(B, NU ## _as_ ## M(ref)) : -1; }
+
+/* M is the union member name and T is its type, i.e. the qualified name. */
+#define __flatbuffers_build_union_struct_member_field(NS, N, NU, M, T)\
+static inline int N ## _ ## M ## _add(NS ## builder_t *B, T ## _ref_t ref)\
+{ return N ## _add(B, NU ## _as_ ## M (ref)); }\
+static inline T ## _t *N ## _ ## M ## _start(NS ## builder_t *B)\
+{ return T ## _start(B); }\
+static inline int N ## _ ## M ## _end(NS ## builder_t *B)\
+{ T ## _ref_t ref = T ## _end(B);\
+  return ref ? N ## _ ## M ## _add(B, ref) : -1; }\
+static inline int N ## _ ## M ## _create(NS ## builder_t *B __ ## T ##_formal_args)\
+{ T ## _ref_t ref = T ## _create(B __ ## T ## _call_args);\
+  return ref ? N ## _add(B, NU ## _as_ ## M(ref)) : -1; }\
+static inline int N ## _ ## M ## _end_pe(NS ## builder_t *B)\
+{ T ## _ref_t ref = T ## _end_pe(B);\
+  return ref ? N ## _add(B, NU ## _as_ ## M(ref)) : -1; }\
+static inline int N ## _ ## M ## _clone(NS ## builder_t *B, T ## _struct_t p)\
+{ T ## _ref_t ref = T ## _clone(B, p);\
+  return ref ? N ## _add(B, NU ## _as_ ## M(ref)) : -1; }
+
+#define __flatbuffers_build_union_string_member_field(NS, N, NU, M)\
+static inline int N ## _ ## M ## _add(NS ## builder_t *B, NS ## string_ref_t ref)\
+{ return N ## _add(B, NU ## _as_ ## M (ref)); }\
+__flatbuffers_build_string_field_ops(NS, N ## _ ## M)
 
 /* NS: common namespace, ID: table field id (not offset), TN: name of type T,
  * S: sizeof of scalar type, A: alignment of type T, default value V of type T. */
@@ -348,13 +412,13 @@ static inline int N ## _add(NS ## builder_t *B, const T v)\
   TN ## _assign_to_pe(_p, v); return 0; }\
 static inline int N ## _force_add(NS ## builder_t *B, const T v)\
 { T *_p; if (!(_p = (T *)flatcc_builder_table_add(B, ID, S, A))) return -1;\
-  TN ## _assign_to_pe(_p, v); return 0; }\
+  TN ## _assign_to_pe(_p, v); return 0; }
 
 #define __flatbuffers_build_struct_field(ID, NS, N, TN, S, A)\
 static inline TN ## _t *N ## _start(NS ## builder_t *B)\
 { return (TN ## _t *)flatcc_builder_table_add(B, ID, S, A); }\
 static inline int N ## _end(NS ## builder_t *B)\
-{ if (!NS ## is_native_pe()) { TN ## _to_pe(flatcc_builder_table_edit(B, S)); } return 0; }\
+{ if (!NS ## is_native_pe()) { TN ## _to_pe((TN ## _t *)flatcc_builder_table_edit(B, S)); } return 0; }\
 static inline int N ## _end_pe(NS ## builder_t *B) { return 0; }\
 static inline int N ## _create(NS ## builder_t *B __ ## TN ## _formal_args)\
 { TN ## _t *_p = N ## _start(B); if (!_p) return 0; TN ##_assign_to_pe(_p __ ## TN ## _call_args);\
@@ -394,9 +458,7 @@ static inline int N ## _create(NS ## builder_t *B, const TN ## _ref_t *data, siz
 { return N ## _add(B, flatcc_builder_create_offset_vector(B, data, len)); }\
 __flatbuffers_build_offset_vector_ops(NS, N, N, TN)
 
-#define __flatbuffers_build_string_field(ID, NS, N)\
-static inline int N ## _add(NS ## builder_t *B, NS ## string_ref_t ref)\
-{ NS ## string_ref_t *_p; return (ref && (_p = flatcc_builder_table_add_offset(B, ID))) ? ((*_p = ref), 0) : -1; }\
+#define __flatbuffers_build_string_field_ops(NS, N)\
 static inline int N ## _start(NS ## builder_t *B)\
 { return flatcc_builder_start_string(B); }\
 static inline int N ## _end(NS ## builder_t *B)\
@@ -413,10 +475,66 @@ static inline int N ## _slice(NS ## builder_t *B, NS ## string_t string, size_t
 { return N ## _add(B, NS ## string_slice(B, string, index, len)); }\
 __flatbuffers_build_string_ops(NS, N)
 
+#define __flatbuffers_build_string_field(ID, NS, N)\
+static inline int N ## _add(NS ## builder_t *B, NS ## string_ref_t ref)\
+{ NS ## string_ref_t *_p; return (ref && (_p = flatcc_builder_table_add_offset(B, ID))) ? ((*_p = ref), 0) : -1; }\
+__flatbuffers_build_string_field_ops(NS, N)
+
 #define __flatbuffers_build_table_vector_field(ID, NS, N, TN)\
 __flatbuffers_build_offset_vector_field(ID, NS, N, TN)\
 __flatbuffers_build_table_vector_ops(NS, N, TN)
 
+#define __flatbuffers_build_union_vector_field(ID, NS, N, TN)\
+static inline int N ## _add(NS ## builder_t *B, TN ## _union_vec_ref_t uvref)\
+{ NS ## vec_ref_t *_p; if (!uvref.types || !uvref.members) return uvref.types == uvref.members ? 0 : -1;\
+  if (!(_p = flatcc_builder_table_add_offset(B, ID - 1))) return -1; *_p = uvref.types;\
+  if (!(_p = flatcc_builder_table_add_offset(B, ID))) return -1; *_p = uvref.members; return 0; }\
+static inline int N ## _start(NS ## builder_t *B)\
+{ return flatcc_builder_start_union_vector(B); }\
+static inline int N ## _end(NS ## builder_t *B)\
+{ return N ## _add(B, flatcc_builder_end_union_vector(B)); }\
+static inline int N ## _create(NS ## builder_t *B, const TN ## _union_ref_t *data, size_t len)\
+{ return N ## _add(B, flatcc_builder_create_union_vector(B, data, len)); }\
+__flatbuffers_build_union_vector_ops(NS, N, N, TN)
+
+#define __flatbuffers_build_union_table_vector_member_field(NS, N, NU, M, T)\
+static inline int N ## _ ## M ## _push_start(NS ## builder_t *B)\
+{ return T ## _start(B); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_end(NS ## builder_t *B)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M (T ## _end(B))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push(NS ## builder_t *B, T ## _ref_t ref)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M (ref)); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_create(NS ## builder_t *B __ ## T ##_formal_args)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(T ## _create(B __ ## T ## _call_args))); }
+
+#define __flatbuffers_build_union_struct_vector_member_field(NS, N, NU, M, T)\
+static inline T ## _t *N ## _ ## M ## _push_start(NS ## builder_t *B)\
+{ return T ## _start(B); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_end(NS ## builder_t *B)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M (T ## _end(B))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push(NS ## builder_t *B, T ## _ref_t ref)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M (ref)); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_create(NS ## builder_t *B __ ## T ##_formal_args)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(T ## _create(B __ ## T ## _call_args))); }
+
+#define __flatbuffers_build_union_string_vector_member_field(NS, N, NU, M)\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push(NS ## builder_t *B, NS ## string_ref_t ref)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M (ref)); }\
+static inline int N ## _ ## M ## _push_start(NS ## builder_t *B)\
+{ return NS ## string_start(B); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_end(NS ## builder_t *B)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(NS ## string_end(B))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_create(NS ## builder_t *B, const char *s, size_t len)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(NS ## string_create(B, s, len))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_create_str(NS ## builder_t *B, const char *s)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(NS ## string_create_str(B, s))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_create_strn(NS ## builder_t *B, const char *s, size_t max_len)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(NS ## string_create_strn(B, s, max_len))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_clone(NS ## builder_t *B, NS ## string_t string)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(NS ## string_clone(B, string))); }\
+static inline NU ## _union_ref_t *N ## _ ## M ## _push_slice(NS ## builder_t *B, NS ## string_t string, size_t index, size_t len)\
+{ return NU ## _vec_push(B, NU ## _as_ ## M(NS ## string_slice(B, string, index, len))); }
+
 #define __flatbuffers_build_string_vector_field(ID, NS, N)\
 __flatbuffers_build_offset_vector_field(ID, NS, N, NS ## string)\
 __flatbuffers_build_string_vector_ops(NS, N)
diff --git a/include/flatcc/reflection/flatbuffers_common_reader.h b/include/flatcc/reflection/flatbuffers_common_reader.h
index 54e23ee2..96d3b626 100644
--- a/include/flatcc/reflection/flatbuffers_common_reader.h
+++ b/include/flatcc/reflection/flatbuffers_common_reader.h
@@ -1,7 +1,7 @@
 #ifndef FLATBUFFERS_COMMON_READER_H
 #define FLATBUFFERS_COMMON_READER_H
 
-/* Generated by flatcc 0.4.3 FlatBuffers schema compiler for C by dvide.com */
+/* Generated by flatcc 0.5.0 FlatBuffers schema compiler for C by dvide.com */
 
 /* Common FlatBuffers read functionality for C. */
 
@@ -24,18 +24,6 @@ flatbuffers_voffset_t offset = 0;\
     }\
 }
 #define __flatbuffers_field_present(ID, t) { __flatbuffers_read_vt(ID, offset, t) return offset != 0; }
-#define __flatbuffers_union_type_field(ID, t)\
-{\
-    __flatbuffers_read_vt(ID, offset, t)\
-    return offset ? __flatbuffers_read_scalar_at_byteoffset(__flatbuffers_utype, t, offset) : 0;\
-}
-#define __flatbuffers_define_union_field(ID, N, NK, r)\
-static inline flatbuffers_utype_t N ## _ ## NK ## _type(N ## _table_t t)\
-__flatbuffers_union_type_field(((ID) - 1), t)\
-static inline flatbuffers_generic_t N ## _ ## NK(N ## _table_t t)\
-__flatbuffers_table_field(flatbuffers_generic_t, ID, t, r)\
-static inline int N ## _ ## NK ## _is_present(N ## _table_t t)\
-__flatbuffers_field_present(ID, t)
 #define __flatbuffers_define_scalar_field(ID, N, NK, TK, T, V)\
 static inline T N ## _ ## NK (N ## _table_t t)\
 { __flatbuffers_read_vt(ID, offset, t)\
@@ -120,6 +108,69 @@ __flatbuffers_vec_len(vec)
 static inline flatbuffers_string_t flatbuffers_string_vec_at(flatbuffers_string_vec_t vec, size_t i)
 __flatbuffers_offset_vec_at(flatbuffers_string_t, vec, i, sizeof(vec[0]))
 typedef const void *flatbuffers_generic_t;
+static inline flatbuffers_string_t flatbuffers_string_cast_from_generic(const flatbuffers_generic_t p)\
+{ return p ? ((const char *)p) + __flatbuffers_uoffset__size() : 0; }
+typedef const flatbuffers_uoffset_t *flatbuffers_generic_vec_t;
+typedef flatbuffers_uoffset_t *flatbuffers_generic_table_mutable_vec_t;
+static inline size_t flatbuffers_generic_vec_len(flatbuffers_generic_vec_t vec)
+__flatbuffers_vec_len(vec)
+static inline flatbuffers_generic_t flatbuffers_generic_vec_at(flatbuffers_generic_vec_t vec, size_t i)
+__flatbuffers_offset_vec_at(flatbuffers_generic_t, vec, i, 0)\
+static inline flatbuffers_generic_t flatbuffers_generic_vec_at_as_string(flatbuffers_generic_vec_t vec, size_t i)
+__flatbuffers_offset_vec_at(flatbuffers_generic_t, vec, i, sizeof(vec[0]))\
+typedef struct flatbuffers_union {
+    flatbuffers_union_type_t type;
+    flatbuffers_generic_t member;
+} flatbuffers_union_t;
+typedef struct flatbuffers_union_vec {
+    const flatbuffers_union_type_t *type;
+    const flatbuffers_uoffset_t *member;
+} flatbuffers_union_vec_t;
+#define __flatbuffers_union_type_field(ID, t)\
+{\
+    __flatbuffers_read_vt(ID, offset, t)\
+    return offset ? __flatbuffers_read_scalar_at_byteoffset(__flatbuffers_utype, t, offset) : 0;\
+}
+static inline flatbuffers_string_t flatbuffers_string_cast_from_union(const flatbuffers_union_t u)\
+{ return flatbuffers_string_cast_from_generic(u.member); }
+#define __flatbuffers_define_union_field(NS, ID, N, NK, T, r)\
+static inline T ## _union_type_t N ## _ ## NK ## _type(N ## _table_t t)\
+__## NS ## union_type_field(((ID) - 1), t)\
+static inline NS ## generic_t N ## _ ## NK(N ## _table_t t)\
+__## NS ## table_field(NS ## generic_t, ID, t, r)\
+static inline int N ## _ ## NK ## _is_present(N ## _table_t t)\
+__## NS ## field_present(ID, t)\
+static inline T ## _union_t N ## _ ## NK ## _union(N ## _table_t t)\
+{ T ## _union_t u = { 0, 0 }; u.type = N ## _ ## NK ## _type(t);\
+  if (u.type == 0) return u; u.member = N ## _ ## NK (t); return u; }\
+static inline NS ## string_t N ## _ ## NK ## _as_string(N ## _table_t t)\
+{ return NS ## string_cast_from_generic(N ## _ ## NK(t)); }\
+
+#define __flatbuffers_define_union_vector_ops(NS, T)\
+static inline size_t T ## _union_vec_len(T ## _union_vec_t uv)\
+{ return NS ## vec_len(uv.type); }\
+static inline T ## _union_t T ## _union_vec_at(T ## _union_vec_t uv, size_t i)\
+{ T ## _union_t u = { 0, 0 }; size_t n = NS ## vec_len(uv.type);\
+  assert(n > (i) && "index out of range"); u.type = uv.type[i];\
+  /* Unknown type is treated as NONE for schema evolution. */\
+  if (u.type == 0) return u;\
+  u.member = NS ## generic_vec_at(uv.member, i); return u; }\
+static inline NS ## string_t T ## _union_vec_at_as_string(T ## _union_vec_t uv, size_t i)\
+{ return NS ## generic_vec_at_as_string(uv.member, i); }\
+
+#define __flatbuffers_define_union_vector(NS, T)\
+typedef NS ## union_vec_t T ## _union_vec_t;\
+__## NS ## define_union_vector_ops(NS, T)
+#define __flatbuffers_define_union(NS, T)\
+typedef NS ## union_t T ## _union_t;\
+__## NS ## define_union_vector(NS, T)
+#define __flatbuffers_define_union_vector_field(NS, ID, N, NK, T, r)\
+__## NS ## define_vector_field(ID - 1, N, NK ## _type, T ## _vec_t, r)\
+__## NS ## define_vector_field(ID, N, NK, flatbuffers_generic_vec_t, r)\
+static inline T ## _union_vec_t N ## _ ## NK ## _union(N ## _table_t t)\
+{ T ## _union_vec_t uv; uv.type = N ## _ ## NK ## _type(t); uv.member = N ## _ ## NK(t);\
+  assert(NS ## vec_len(uv.type) == NS ## vec_len(uv.member)\
+  && "union vector type length mismatch"); return uv; }
 #include <string.h>
 static size_t flatbuffers_not_found = (size_t)-1;
 static size_t flatbuffers_end = (size_t)-1;
@@ -352,6 +403,7 @@ __flatbuffers_define_scalar_vector(flatbuffers_uint64, uint64_t)
 __flatbuffers_define_scalar_vector(flatbuffers_int64, int64_t)
 __flatbuffers_define_scalar_vector(flatbuffers_float, float)
 __flatbuffers_define_scalar_vector(flatbuffers_double, double)
+__flatbuffers_define_scalar_vector(flatbuffers_union_type, flatbuffers_union_type_t)
 static inline size_t flatbuffers_string_vec_find(flatbuffers_string_vec_t vec, const char *s)
 __flatbuffers_find_by_string_field(__flatbuffers_identity, vec, flatbuffers_string_vec_at, flatbuffers_string_vec_len, s)
 static inline size_t flatbuffers_string_vec_find_n(flatbuffers_string_vec_t vec, const char *s, size_t n)
diff --git a/include/flatcc/reflection/reflection_builder.h b/include/flatcc/reflection/reflection_builder.h
index 33642733..531561ef 100644
--- a/include/flatcc/reflection/reflection_builder.h
+++ b/include/flatcc/reflection/reflection_builder.h
@@ -1,7 +1,7 @@
 #ifndef REFLECTION_BUILDER_H
 #define REFLECTION_BUILDER_H
 
-/* Generated by flatcc 0.4.3 FlatBuffers schema compiler for C by dvide.com */
+/* Generated by flatcc 0.5.0 FlatBuffers schema compiler for C by dvide.com */
 
 #ifndef REFLECTION_READER_H
 #include "reflection_reader.h"
diff --git a/include/flatcc/reflection/reflection_reader.h b/include/flatcc/reflection/reflection_reader.h
index 616480cd..c726a502 100644
--- a/include/flatcc/reflection/reflection_reader.h
+++ b/include/flatcc/reflection/reflection_reader.h
@@ -1,7 +1,7 @@
 #ifndef REFLECTION_READER_H
 #define REFLECTION_READER_H
 
-/* Generated by flatcc 0.4.3 FlatBuffers schema compiler for C by dvide.com */
+/* Generated by flatcc 0.5.0 FlatBuffers schema compiler for C by dvide.com */
 
 #ifndef FLATBUFFERS_COMMON_READER_H
 #include "flatbuffers_common_reader.h"
@@ -36,6 +36,36 @@ typedef flatbuffers_uoffset_t *reflection_Object_mutable_vec_t;
 typedef const struct reflection_Schema_table *reflection_Schema_table_t;
 typedef const flatbuffers_uoffset_t *reflection_Schema_vec_t;
 typedef flatbuffers_uoffset_t *reflection_Schema_mutable_vec_t;
+#ifndef reflection_Type_identifier
+#define reflection_Type_identifier flatbuffers_identifier
+#endif
+#define reflection_Type_type_hash ((flatbuffers_thash_t)0x44c8fe5e)
+#define reflection_Type_type_identifier "\x5e\xfe\xc8\x44"
+#ifndef reflection_EnumVal_identifier
+#define reflection_EnumVal_identifier flatbuffers_identifier
+#endif
+#define reflection_EnumVal_type_hash ((flatbuffers_thash_t)0x9531c946)
+#define reflection_EnumVal_type_identifier "\x46\xc9\x31\x95"
+#ifndef reflection_Enum_identifier
+#define reflection_Enum_identifier flatbuffers_identifier
+#endif
+#define reflection_Enum_type_hash ((flatbuffers_thash_t)0xacffa90f)
+#define reflection_Enum_type_identifier "\x0f\xa9\xff\xac"
+#ifndef reflection_Field_identifier
+#define reflection_Field_identifier flatbuffers_identifier
+#endif
+#define reflection_Field_type_hash ((flatbuffers_thash_t)0x9f7e408a)
+#define reflection_Field_type_identifier "\x8a\x40\x7e\x9f"
+#ifndef reflection_Object_identifier
+#define reflection_Object_identifier flatbuffers_identifier
+#endif
+#define reflection_Object_type_hash ((flatbuffers_thash_t)0xb09729bd)
+#define reflection_Object_type_identifier "\xbd\x29\x97\xb0"
+#ifndef reflection_Schema_identifier
+#define reflection_Schema_identifier flatbuffers_identifier
+#endif
+#define reflection_Schema_type_hash ((flatbuffers_thash_t)0xfaf93779)
+#define reflection_Schema_type_identifier "\x79\x37\xf9\xfa"
 
 typedef int8_t reflection_BaseType_enum_t;
 __flatbuffers_define_integer_type(reflection_BaseType, reflection_BaseType_enum_t, 8)
@@ -81,15 +111,34 @@ static inline const char *reflection_BaseType_name(reflection_BaseType_enum_t va
     }
 }
 
+static inline int reflection_BaseType_is_known_value(reflection_BaseType_enum_t value)
+{
+    switch (value) {
+    case reflection_BaseType_None: return 1;
+    case reflection_BaseType_UType: return 1;
+    case reflection_BaseType_Bool: return 1;
+    case reflection_BaseType_Byte: return 1;
+    case reflection_BaseType_UByte: return 1;
+    case reflection_BaseType_Short: return 1;
+    case reflection_BaseType_UShort: return 1;
+    case reflection_BaseType_Int: return 1;
+    case reflection_BaseType_UInt: return 1;
+    case reflection_BaseType_Long: return 1;
+    case reflection_BaseType_ULong: return 1;
+    case reflection_BaseType_Float: return 1;
+    case reflection_BaseType_Double: return 1;
+    case reflection_BaseType_String: return 1;
+    case reflection_BaseType_Vector: return 1;
+    case reflection_BaseType_Obj: return 1;
+    case reflection_BaseType_Union: return 1;
+    default: return 0;
+    }
+}
+
 
 
 struct reflection_Type_table { uint8_t unused__; };
 
-#ifndef reflection_Type_identifier
-#define reflection_Type_identifier flatbuffers_identifier
-#endif
-#define reflection_Type_type_hash ((flatbuffers_thash_t)0x44c8fe5e)
-#define reflection_Type_type_identifier "\x5e\xfe\xc8\x44"
 static inline size_t reflection_Type_vec_len(reflection_Type_vec_t vec)
 __flatbuffers_vec_len(vec)
 static inline reflection_Type_table_t reflection_Type_vec_at(reflection_Type_vec_t vec, size_t i)
@@ -102,11 +151,6 @@ __flatbuffers_define_scalar_field(2, reflection_Type, index, flatbuffers_int32,
 
 struct reflection_EnumVal_table { uint8_t unused__; };
 
-#ifndef reflection_EnumVal_identifier
-#define reflection_EnumVal_identifier flatbuffers_identifier
-#endif
-#define reflection_EnumVal_type_hash ((flatbuffers_thash_t)0x9531c946)
-#define reflection_EnumVal_type_identifier "\x46\xc9\x31\x95"
 static inline size_t reflection_EnumVal_vec_len(reflection_EnumVal_vec_t vec)
 __flatbuffers_vec_len(vec)
 static inline reflection_EnumVal_table_t reflection_EnumVal_vec_at(reflection_EnumVal_vec_t vec, size_t i)
@@ -125,11 +169,6 @@ __flatbuffers_define_table_field(2, reflection_EnumVal, object, reflection_Objec
 
 struct reflection_Enum_table { uint8_t unused__; };
 
-#ifndef reflection_Enum_identifier
-#define reflection_Enum_identifier flatbuffers_identifier
-#endif
-#define reflection_Enum_type_hash ((flatbuffers_thash_t)0xacffa90f)
-#define reflection_Enum_type_identifier "\x0f\xa9\xff\xac"
 static inline size_t reflection_Enum_vec_len(reflection_Enum_vec_t vec)
 __flatbuffers_vec_len(vec)
 static inline reflection_Enum_table_t reflection_Enum_vec_at(reflection_Enum_vec_t vec, size_t i)
@@ -148,11 +187,6 @@ __flatbuffers_define_table_field(3, reflection_Enum, underlying_type, reflection
 
 struct reflection_Field_table { uint8_t unused__; };
 
-#ifndef reflection_Field_identifier
-#define reflection_Field_identifier flatbuffers_identifier
-#endif
-#define reflection_Field_type_hash ((flatbuffers_thash_t)0x9f7e408a)
-#define reflection_Field_type_identifier "\x8a\x40\x7e\x9f"
 static inline size_t reflection_Field_vec_len(reflection_Field_vec_t vec)
 __flatbuffers_vec_len(vec)
 static inline reflection_Field_table_t reflection_Field_vec_at(reflection_Field_vec_t vec, size_t i)
@@ -176,11 +210,6 @@ __flatbuffers_define_scalar_field(8, reflection_Field, key, flatbuffers_bool, fl
 
 struct reflection_Object_table { uint8_t unused__; };
 
-#ifndef reflection_Object_identifier
-#define reflection_Object_identifier flatbuffers_identifier
-#endif
-#define reflection_Object_type_hash ((flatbuffers_thash_t)0xb09729bd)
-#define reflection_Object_type_identifier "\xbd\x29\x97\xb0"
 static inline size_t reflection_Object_vec_len(reflection_Object_vec_t vec)
 __flatbuffers_vec_len(vec)
 static inline reflection_Object_table_t reflection_Object_vec_at(reflection_Object_vec_t vec, size_t i)
@@ -200,11 +229,6 @@ __flatbuffers_define_scalar_field(4, reflection_Object, bytesize, flatbuffers_in
 
 struct reflection_Schema_table { uint8_t unused__; };
 
-#ifndef reflection_Schema_identifier
-#define reflection_Schema_identifier flatbuffers_identifier
-#endif
-#define reflection_Schema_type_hash ((flatbuffers_thash_t)0xfaf93779)
-#define reflection_Schema_type_identifier "\x79\x37\xf9\xfa"
 static inline size_t reflection_Schema_vec_len(reflection_Schema_vec_t vec)
 __flatbuffers_vec_len(vec)
 static inline reflection_Schema_table_t reflection_Schema_vec_at(reflection_Schema_vec_t vec, size_t i)
diff --git a/include/flatcc/reflection/reflection_verifier.h b/include/flatcc/reflection/reflection_verifier.h
index 649b82e2..8ee35867 100644
--- a/include/flatcc/reflection/reflection_verifier.h
+++ b/include/flatcc/reflection/reflection_verifier.h
@@ -1,7 +1,7 @@
 #ifndef REFLECTION_VERIFIER_H
 #define REFLECTION_VERIFIER_H
 
-/* Generated by flatcc 0.4.3 FlatBuffers schema compiler for C by dvide.com */
+/* Generated by flatcc 0.5.0 FlatBuffers schema compiler for C by dvide.com */
 
 #ifndef REFLECTION_READER_H
 #include "reflection_reader.h"