diff --git a/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/cdr_stream.hpp b/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/cdr_stream.hpp
index 86302b19..865f60e6 100644
--- a/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/cdr_stream.hpp
+++ b/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/cdr_stream.hpp
@@ -432,6 +432,21 @@ class OMG_DDS_API cdr_stream {
      */
     virtual bool finish_member(const entity_properties_t &props, member_id_set &member_ids, bool is_set = true);
 
+    /**
+     * @brief
+     * Function declaration for finishing an existing member.
+     *
+     * This function is called by next_entity for each entity which is iterated over.
+     * Depending on the implementation and mode header length fields may be completed.
+     * This function can be overridden in cdr streaming implementations.
+     *
+     * @param[in] props Properties of the member to finish.
+     * @param[in] is_set Whether the entity represented by prop is present, if it is an optional entity.
+     *
+     * @return Whether the operation was completed succesfully.
+     */
+    virtual bool finish_member_unchecked(const entity_properties_t &props, bool is_set = true);
+
     /**
      * @brief
      * Function declaration for retrieving the next entity to be operated on by the streamer.
@@ -481,7 +496,20 @@ class OMG_DDS_API cdr_stream {
      *
      * @return Whether the struct is complete and correct.
      */
-    virtual bool finish_struct(const entity_properties_t &props, const member_id_set &member_ids);
+    virtual bool finish_struct(const entity_properties_t &props, const member_id_set &member_ids) {return check_struct_completeness(props, member_ids);}
+
+    /**
+     * @brief
+     * Function declaration for finishing a parameter list.
+     *
+     * This function is called by the generated functions for the entity, and will trigger the necessary actions on finishing the current struct.
+     * I.E. finishing headers, writing length fields.
+     *
+     * @param[in] props The entity whose members might be represented by a parameter list.
+     *
+     * @return Whether the struct is complete and correct.
+     */
+    virtual bool finish_struct_unchecked(const entity_properties_t &props) {(void)props; return true;}
 
     /**
      * @brief
@@ -941,6 +969,39 @@ bool max_string(S& str, const T& max_sz, size_t N)
   return true;
 }
 
+/**
+ * @brief
+ * Sequence of base types read function.
+ *
+ * This is called when a resize + memcpy is way less efficient than an assign,
+ * as this skips the default initialization of entities in the sequence.
+ *
+ * @param[in, out] str The stream being read from.
+ * @param[in] toread The sequence being read into.
+ * @param[in] N Number of base entities to read.
+ *
+ * @return Whether the operation was completed succesfully.
+ */
+template<typename S, template<typename,typename> class V, typename T, typename A, std::enable_if_t<std::is_base_of<cdr_stream, S>::value && std::is_arithmetic<T>::value && !std::is_same<T,bool>::value, bool> = true >
+bool read(S& str, V<T,A> &toread, size_t N)
+{
+  if (str.position() == SIZE_MAX
+   || !str.align(sizeof(T), false)
+   || !str.bytes_available(sizeof(T)*N))
+    return false;
+
+  auto ptr = reinterpret_cast<const T*>(str.get_cursor());
+  toread.assign(ptr, ptr+N);
+  str.incr_position(N*sizeof(T));
+
+  if (str.swap_endianness()) {
+    for (auto &e:toread)
+      byte_swap(&e);
+  }
+
+  return true;
+}
+
 }
 }
 }
diff --git a/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.hpp b/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.hpp
index 87d8283a..96916954 100644
--- a/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.hpp
+++ b/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.hpp
@@ -59,12 +59,11 @@ class OMG_DDS_API xcdr_v1_stream : public cdr_stream {
    * Determines whether a header is necessary for this entity through header_necessary, and if it is, completes the previous header.
    *
    * @param[in] prop Properties of the member to finish.
-   * @param[in] member_ids Container for the member ids of members succesfully streamed at this level
    * @param[in] is_set Whether the entity represented by prop is present, if it is an optional entity.
    *
    * @return Whether the operation was completed succesfully.
    */
-  bool finish_member(const entity_properties_t &prop, member_id_set &member_ids, bool is_set = true);
+  bool finish_member_unchecked(const entity_properties_t &prop, bool is_set = true);
 
   /**
    * @brief
@@ -99,11 +98,10 @@ class OMG_DDS_API xcdr_v1_stream : public cdr_stream {
    * Adds the final parameter list entry if necessary when writing to the stream.
    *
    * @param[in] props The property tree to get the next entity from.
-   * @param[in] member_ids Container for the member ids of members succesfully streamed at this level
    *
    * @return Whether the struct is complete and correct.
    */
-  bool finish_struct(const entity_properties_t &props, const member_id_set &member_ids);
+  bool finish_struct_unchecked(const entity_properties_t &props);
 
 private:
 
diff --git a/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.hpp b/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.hpp
index 34298195..511d400c 100644
--- a/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.hpp
+++ b/src/ddscxx/include/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.hpp
@@ -65,12 +65,11 @@ class OMG_DDS_API xcdr_v2_stream : public cdr_stream {
    * Determines whether a header is necessary for this entity through em_header_necessary, and if it is, completes the previous header.
    *
    * @param[in] prop Properties of the member to finish.
-   * @param[in] member_ids Container for the member ids of members succesfully streamed at this level
    * @param[in] is_set Whether the entity represented by prop is present, if it is an optional entity.
    *
    * @return Whether the operation was completed succesfully.
    */
-  bool finish_member(const entity_properties_t &prop, member_id_set &member_ids, bool is_set = true);
+  bool finish_member_unchecked(const entity_properties_t &prop, bool is_set = true);
 
   /**
    * @brief
@@ -123,6 +122,18 @@ class OMG_DDS_API xcdr_v2_stream : public cdr_stream {
    */
   bool finish_struct(const entity_properties_t &props, const member_id_set &member_ids);
 
+  /**
+   * @brief
+   * Finish the current struct.
+   *
+   * This function is called by the generated streaming functions, and will finish the current parameter list, if that is relevant for it.
+   *
+   * @param[in] props The entity whose members might be represented by a parameter list.
+   *
+   * @return Whether the struct is complete and correct.
+   */
+  bool finish_struct_unchecked(const entity_properties_t &props);
+
   /**
    * @brief
    * Function declaration for starting an array or sequence of non-primitive types.
diff --git a/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/cdr_stream.cpp b/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/cdr_stream.cpp
index 1d673c16..ad4e42bc 100644
--- a/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/cdr_stream.cpp
+++ b/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/cdr_stream.cpp
@@ -53,17 +53,6 @@ bool cdr_stream::align(size_t newalignment, bool add_zeroes)
   return true;
 }
 
-bool cdr_stream::finish_struct(const entity_properties_t &props, const member_id_set &member_ids)
-{
-  switch (m_mode) {
-    case stream_mode::read:
-      return check_struct_completeness(props, member_ids);
-      break;
-    default:
-      return true;
-  }
-}
-
 const entity_properties_t *cdr_stream::first_entity(const entity_properties_t *props)
 {
   const entity_properties_t *prop = props->first_member;
@@ -140,11 +129,19 @@ bool cdr_stream::check_struct_completeness(const entity_properties_t &props, con
 
 bool cdr_stream::finish_member(const entity_properties_t &props, member_id_set &member_ids, bool is_set)
 {
+  if (!finish_member_unchecked(props, is_set))
+    return false;
+
   if (is_set)
     member_ids.insert(props.m_id);
   return true;
 }
 
+bool cdr_stream::finish_member_unchecked(const entity_properties_t &, bool)
+{
+  return true;
+}
+
 }
 }
 }
diff --git a/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.cpp b/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.cpp
index c34032a1..e18325e1 100644
--- a/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.cpp
+++ b/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v1_ser.cpp
@@ -55,7 +55,7 @@ bool xcdr_v1_stream::start_member(const entity_properties_t &prop, bool is_set)
   return cdr_stream::start_member(prop, is_set);
 }
 
-bool xcdr_v1_stream::finish_member(const entity_properties_t &prop, member_id_set &member_ids, bool is_set)
+bool xcdr_v1_stream::finish_member_unchecked(const entity_properties_t &prop, bool is_set)
 {
   if (header_necessary(prop)) {
     switch (m_mode) {
@@ -73,7 +73,7 @@ bool xcdr_v1_stream::finish_member(const entity_properties_t &prop, member_id_se
   }
 
   pop_member_start();
-  return cdr_stream::finish_member(prop, member_ids, is_set);
+  return cdr_stream::finish_member_unchecked(prop, is_set);
 }
 
 const entity_properties_t* xcdr_v1_stream::next_entity(const entity_properties_t *prop)
@@ -288,7 +288,7 @@ bool xcdr_v1_stream::finish_write_header(const entity_properties_t &props)
   return true;
 }
 
-bool xcdr_v1_stream::finish_struct(const entity_properties_t &props, const member_id_set &member_ids)
+bool xcdr_v1_stream::finish_struct_unchecked(const entity_properties_t &props)
 {
   switch (m_mode) {
     case stream_mode::write:
@@ -300,11 +300,8 @@ bool xcdr_v1_stream::finish_struct(const entity_properties_t &props, const membe
       if (list_necessary(props))
         return move_final_list_entry();
       break;
-    case stream_mode::read:
-      return check_struct_completeness(props, member_ids);
-      break;
     default:
-      return false;
+      break;
   }
   return true;
 }
diff --git a/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.cpp b/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.cpp
index 31eac17b..9044a8df 100644
--- a/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.cpp
+++ b/src/ddscxx/src/org/eclipse/cyclonedds/core/cdr/extended_cdr_v2_ser.cpp
@@ -64,7 +64,7 @@ bool xcdr_v2_stream::start_member(const entity_properties_t &prop, bool is_set)
   return cdr_stream::start_member(prop, is_set);
 }
 
-bool xcdr_v2_stream::finish_member(const entity_properties_t &prop, member_id_set &member_ids, bool is_set)
+bool xcdr_v2_stream::finish_member_unchecked(const entity_properties_t &prop, bool is_set)
 {
   switch (m_mode) {
     case stream_mode::write:
@@ -83,7 +83,7 @@ bool xcdr_v2_stream::finish_member(const entity_properties_t &prop, member_id_se
 
   m_consecutives.pop();
   pop_member_start();
-  return cdr_stream::finish_member(prop, member_ids, is_set);
+  return cdr_stream::finish_member_unchecked(prop, is_set);
 }
 
 bool xcdr_v2_stream::write_d_header()
@@ -313,21 +313,19 @@ bool xcdr_v2_stream::start_struct(const entity_properties_t &props)
 
 bool xcdr_v2_stream::finish_struct(const entity_properties_t &props, const member_id_set &member_ids)
 {
-  switch (m_mode) {
-    case stream_mode::write:
-      if (d_header_necessary(props) && !finish_d_header())
-        return false;
-      break;
-    case stream_mode::read:
-      if (!check_struct_completeness(props, member_ids))
-        return false;
-      else if (d_header_necessary(props))
-        m_buffer_end.pop();
-      break;
-    default:
-      break;
-  }
+  if (!cdr_stream::finish_struct(props, member_ids))
+    return false;
+  else if (d_header_necessary(props))
+    m_buffer_end.pop();
+
+  return true;
+}
 
+bool xcdr_v2_stream::finish_struct_unchecked(const entity_properties_t &props)
+{
+  if (stream_mode::write == m_mode && d_header_necessary(props) && !finish_d_header())
+    return false;
+  
   return true;
 }
 
diff --git a/src/idlcxx/src/streamers.c b/src/idlcxx/src/streamers.c
index e86e878b..62c430cf 100644
--- a/src/idlcxx/src/streamers.c
+++ b/src/idlcxx/src/streamers.c
@@ -365,7 +365,8 @@ write_base_type_streaming_functions(
   const idl_type_spec_t* type_spec,
   const char* accessor,
   const char* read_accessor,
-  instance_location_t loc)
+  instance_location_t loc,
+  bool skip_reads)
 {
   const char* fmt =
     "      if (!{T}(streamer, %1$s))\n"
@@ -390,7 +391,7 @@ write_base_type_streaming_functions(
   }
 
   if (multi_putf(streams, CONST, fmt, accessor)
-   || multi_putf(streams, READ, rfmt, read_accessor))
+   || (!skip_reads && multi_putf(streams, READ, rfmt, read_accessor)))
     return IDL_RETCODE_NO_MEMORY;
 
   return IDL_RETCODE_OK;
@@ -402,24 +403,25 @@ write_streaming_functions(
   const idl_type_spec_t* type_spec,
   const char* accessor,
   const char* read_accessor,
-  instance_location_t loc)
+  instance_location_t loc,
+  bool skip_reads)
 {
   if (idl_is_alias(type_spec)) {
     const idl_typedef_t *td = idl_parent(type_spec);
     const idl_type_spec_t *ts = idl_type_spec(td);
     //if this is an alias for a bare type, just use the bare type
     if (!idl_is_array(td->declarators) && !idl_is_sequence(ts) && (idl_is_base_type(ts) || idl_is_string(ts)))
-      return write_streaming_functions(streams, ts, accessor, read_accessor, loc);
+      return write_streaming_functions(streams, ts, accessor, read_accessor, loc, skip_reads);
     else
       return write_typedef_streaming_functions(streams, type_spec, accessor, read_accessor);
   } else if (idl_is_forward(type_spec)) {
-    return write_streaming_functions(streams, idl_type_spec(type_spec), accessor, read_accessor, loc);
+    return write_streaming_functions(streams, idl_type_spec(type_spec), accessor, read_accessor, loc, skip_reads);
   } else if (idl_is_string(type_spec)) {
     return write_string_streaming_functions(streams, type_spec, accessor, read_accessor);
   } else if (idl_is_union(type_spec) || idl_is_struct(type_spec)) {
     return write_constructed_type_streaming_functions(streams, accessor, read_accessor);
   } else {
-    return write_base_type_streaming_functions(streams, type_spec, accessor, read_accessor, loc);
+    return write_base_type_streaming_functions(streams, type_spec, accessor, read_accessor, loc, skip_reads);
   }
 }
 
@@ -439,7 +441,8 @@ sequence_writes(const idl_pstate_t* pstate,
   size_t depth,
   const char* accessor,
   const char* read_accessor,
-  instance_location_t loc)
+  instance_location_t loc,
+  bool skip_reads)
 {
   const idl_type_spec_t *type_spec = seq->type_spec;
 
@@ -457,7 +460,7 @@ sequence_writes(const idl_pstate_t* pstate,
     if (IDL_PRINTA(&type, get_cpp11_type, type_spec, streams->generator) < 0
       || multi_putf(streams, MOVE | MAX, mfmt, type, depth)
       || multi_putf(streams, WRITE, sfmt, accessor, depth)
-      || multi_putf(streams, READ, sfmt, read_accessor, depth))
+      || (!skip_reads && multi_putf(streams, READ, sfmt, read_accessor, depth)))
         return IDL_RETCODE_NO_MEMORY;
 
     return IDL_RETCODE_OK;
@@ -483,7 +486,7 @@ sequence_writes(const idl_pstate_t* pstate,
     if (unroll_sequence (pstate, streams, (idl_sequence_t*)type_spec, depth + 1, new_accessor, new_read_accessor, loc))
       return IDL_RETCODE_NO_MEMORY;
   } else {
-    if (write_streaming_functions (streams, type_spec, new_accessor, new_read_accessor, loc))
+    if (write_streaming_functions (streams, type_spec, new_accessor, new_read_accessor, loc, skip_reads))
       return IDL_RETCODE_NO_MEMORY;
   }
 
@@ -513,7 +516,7 @@ unroll_sequence(const idl_pstate_t* pstate,
       "        return false;\n";
   static const char* fmt1 =
     "      {\n"
-    "      uint32_t se_%1$u = uint32_t(%2$s.size());\n";
+    "      uint32_t se_%1$u(static_cast<uint32_t>(%2$s.size()));\n";
   static const char* length_check =
     "      if (se_%1$u > %2$u &&\n"
     "          streamer.status(serialization_status::{T}_bound_exceeded))\n"
@@ -523,23 +526,35 @@ unroll_sequence(const idl_pstate_t* pstate,
     "        return false;\n";
   static const char* rfmt =
     "      %1$s.resize(se_%2$u);\n";
+  static const char* rfmt2 =
+    "      if (!read(streamer,%1$s,se_%2$u))\n"
+    "        return false;\n";
   static const char* mfmt =
     "      {\n"
     "      uint32_t se_%1$u = %2$u;\n";
+  static const char* rfmt3 =
+    "      {\n"
+    "      uint32_t se_%1$u(0);\n";
 
   const idl_type_spec_t *root_type_spec = idl_strip(seq->type_spec, IDL_STRIP_ALIASES | IDL_STRIP_FORWARD);
   if (multi_putf(streams, ALL, consec_start_fmt, idl_is_base_type(root_type_spec) && !idl_is_array(root_type_spec) ? "true" : "false"))
     return IDL_RETCODE_NO_MEMORY;
 
-  if (multi_putf(streams, READ, fmt1, depth, read_accessor)
+  bool skip_reads = !idl_is_sequence(seq->type_spec) && idl_is_base_type(root_type_spec) && !(idl_mask(root_type_spec) == IDL_BOOL);
+
+  if (multi_putf(streams, READ, rfmt3, depth)
    || multi_putf(streams, (WRITE | MOVE), fmt1, depth, accessor)
    || multi_putf(streams, MAX, mfmt, depth, maximum)
-   || (maximum && multi_putf(streams, NOMAX, length_check, depth, maximum))
    || multi_putf(streams, ALL, fmt2, depth)
-   || multi_putf(streams, READ, rfmt, read_accessor, depth))
+   || (maximum && multi_putf(streams, NOMAX, length_check, depth, maximum)))
     return IDL_RETCODE_NO_MEMORY;
 
-  if (sequence_writes(pstate, streams, seq, depth, accessor, read_accessor, loc))
+  if (!skip_reads && multi_putf(streams, READ, rfmt, read_accessor, depth))
+    return IDL_RETCODE_NO_MEMORY;
+  else if (skip_reads && multi_putf(streams, READ, rfmt2, read_accessor, depth))
+    return IDL_RETCODE_NO_MEMORY;
+
+  if (sequence_writes(pstate, streams, seq, depth, accessor, read_accessor, loc, skip_reads))
     return IDL_RETCODE_NO_MEMORY;
 
   //close sequence
@@ -655,7 +670,7 @@ process_entity(
     if (unroll_sequence(pstate, streams, (idl_sequence_t*)type_spec, 1, accessor, read_accessor, loc))
       return IDL_RETCODE_NO_MEMORY;
   } else {
-    if (write_streaming_functions(streams, type_spec, accessor, read_accessor, loc))
+    if (write_streaming_functions(streams, type_spec, accessor, read_accessor, loc, false))
       return IDL_RETCODE_NO_MEMORY;
   }
 
@@ -813,17 +828,29 @@ add_member_finish(
   const idl_declarator_t *decl,
   struct streams *streams)
 {
+  const void *_struct = idl_parent(idl_parent(decl));
+  bool is_final = idl_is_extensible(_struct, IDL_FINAL);
+
   if (is_optional(decl)) {
     instance_location_t loc = {.parent = "instance"};
     char *accessor = NULL;
     if (IDL_PRINTA(&accessor, get_instance_accessor, decl, &loc) < 0
      || multi_putf(streams, (WRITE|MOVE), "      }\n")
-     || multi_putf(streams, ALL,
-          "      if (!streamer.finish_member(*prop, member_ids, %1$s.has_value()))\n"
+     || multi_putf(streams, READ,
+          "      if (!streamer.finish_member%1$s(*prop%2$s, %3$s.has_value()))\n"
+          "        return false;\n", is_final ? "_unchecked" : "", is_final ? "" : ", member_ids", accessor)
+     || multi_putf(streams, (WRITE|MOVE),
+          "      if (!streamer.finish_member_unchecked(*prop, %1$s.has_value()))\n"
+          "        return false;\n", accessor)
+     || multi_putf(streams, MAX,
+          "      if (!streamer.finish_member_unchecked(*prop, true))\n"
           "        return false;\n", accessor))
       return IDL_RETCODE_NO_MEMORY;
   } else {
-    if (multi_putf(streams, ALL, "      if (!streamer.finish_member(*prop, member_ids))\n"
+    if (multi_putf(streams, READ,
+          "      if (!streamer.finish_member%1$s(*prop%2$s))\n"
+          "        return false;\n", is_final ? "_unchecked" : "", is_final ? "" : ", member_ids")
+     || multi_putf(streams, CONST, "      if (!streamer.finish_member_unchecked(*prop))\n"
                                  "        return false;\n"))
       return IDL_RETCODE_NO_MEMORY;
   }
@@ -1067,7 +1094,7 @@ print_constructed_type_open(struct streams *streams, const idl_node_t *node)
     "template<typename T, std::enable_if_t<std::is_base_of<cdr_stream, T>::value, bool> = true >\n"
     "bool {T}(T& streamer, {C}%1$s& instance, const entity_properties_t *props) {\n"
     "  (void)instance;\n"
-    "  member_id_set member_ids;\n";
+    "%2$s";
   static const char *pfmt1 =
     "template<>\n"
     "const propvec &get_type_props<%s>()%s";
@@ -1087,10 +1114,11 @@ print_constructed_type_open(struct streams *streams, const idl_node_t *node)
     "  if (!streamer.start_struct(*props))\n"
     "    return false;\n";
 
-
   const char *ext = NULL;
+  bool is_final = false;
   switch (get_extensibility(node)) {
     case IDL_FINAL:
+      is_final = true;
       ext = "ext_final";
       break;
     case IDL_APPENDABLE:
@@ -1103,7 +1131,8 @@ print_constructed_type_open(struct streams *streams, const idl_node_t *node)
       assert(0);
   }
 
-  if (multi_putf(streams, ALL, fmt, name)
+  if (multi_putf(streams, READ, fmt, name, is_final ? "" :  "  member_id_set member_ids;\n")
+   || multi_putf(streams, CONST, fmt, name, "")
    || putf(&streams->props, pfmt1, name, pfmt2)
    || idl_fprintf(streams->generator->header.handle, pfmt1, name, ";\n\n") < 0
    || multi_putf(streams, ALL, sfmt)
@@ -1133,7 +1162,7 @@ print_constructed_type_close(
   const void* node)
 {
   const char *fmt =
-    "  return streamer.finish_struct(*props, member_ids);\n"
+    "  return streamer.finish_struct%1$s(*props%2$s);\n"
     "}\n\n";
   static const char *pfmt =
     "\n  entity_properties_t::finish(props, keylist);\n"
@@ -1158,7 +1187,9 @@ print_constructed_type_close(
     ptr++;
   }
 
-  if (multi_putf(streams, ALL, fmt)
+  bool is_final = idl_is_extensible(node, IDL_FINAL);
+  if (multi_putf(streams, CONST, fmt, "_unchecked", "")
+   || multi_putf(streams, READ, fmt, is_final ? "_unchecked" : "", is_final ? "" : ", member_ids")
    || putf(&streams->props, pfmt)
    || idl_fprintf(streams->generator->header.handle, pfmt2, newname, fullname) < 0)
     return IDL_RETCODE_NO_MEMORY;
@@ -1384,7 +1415,7 @@ process_typedef_decl(
     "template<typename T, std::enable_if_t<std::is_base_of<cdr_stream, T>::value, bool> = true >\n"
     "bool {T}_%1$s(T& streamer, {C}%2$s& instance) {\n"
     "  (void)instance;\n"
-    "  member_id_set member_ids;\n";
+    "%3$s";
   char* name = NULL;
   if (IDL_PRINTA(&name, get_cpp11_name_typedef, declarator, streams->generator) < 0)
     return IDL_RETCODE_NO_MEMORY;
@@ -1398,7 +1429,8 @@ process_typedef_decl(
     ts = ((const idl_sequence_t*)ts)->type_spec;
   }
 
-  if (multi_putf(streams, ALL, fmt, name, fullname))
+  if (multi_putf(streams, READ, fmt, name, fullname, "  member_id_set member_ids;\n")
+   || multi_putf(streams, CONST, fmt, name, fullname, ""))
     return IDL_RETCODE_NO_MEMORY;
 
   if (!idl_is_base_type(ts) && !idl_is_enum(ts) && !idl_is_string(ts) && !idl_is_alias(ts)) {