diff --git a/rosidl_generator_c/resource/msg__functions.c.em b/rosidl_generator_c/resource/msg__functions.c.em
index 5c72068cb..4f1406e83 100644
--- a/rosidl_generator_c/resource/msg__functions.c.em
+++ b/rosidl_generator_c/resource/msg__functions.c.em
@@ -275,6 +275,47 @@ bool
   return true;
 }
 
+bool
+@(message_typename)__copy(
+  const @(message_typename) * input,
+  @(message_typename) * output)
+{
+  if (!input || !output) {
+    return false;
+  }
+@[for member in message.structure.members]@
+  // @(member.name)
+@[  if isinstance(member.type, Array)]@
+  for (size_t i = 0; i < @(member.type.size); ++i) {
+@[     if isinstance(member.type.value_type, (AbstractGenericString, NamespacedType))]@
+    if (!@(basetype_to_c(member.type.value_type))__copy(
+        &(input->@(member.name)[i]), &(output->@(member.name)[i])))
+    {
+      return false;
+    }
+@[     else]@
+    output->@(member.name)[i] = input->@(member.name)[i];
+@[     end if]@
+  }
+@[  elif isinstance(member.type, AbstractSequence)]@
+  if (!@(idl_type_to_c(member.type))__copy(
+      &(input->@(member.name)), &(output->@(member.name))))
+  {
+    return false;
+  }
+@[  elif isinstance(member.type, (AbstractGenericString, NamespacedType))]@
+  if (!@(basetype_to_c(member.type))__copy(
+      &(input->@(member.name)), &(output->@(member.name))))
+  {
+    return false;
+  }
+@[  else]@
+  output->@(member.name) = input->@(member.name);
+@[  end if]@
+@[end for]@
+  return true;
+}
+
 @(message_typename) *
 @(message_typename)__create()
 {
@@ -403,3 +444,45 @@ bool
   }
   return true;
 }
+
+bool
+@(array_typename)__copy(
+  const @(array_typename) * input,
+  @(array_typename) * output)
+{
+  if (!input || !output) {
+    return false;
+  }
+  if (output->capacity < input->size) {
+    const size_t allocation_size =
+      input->size * sizeof(@(message_typename));
+    rcutils_allocator_t allocator = rcutils_get_default_allocator();
+    @(message_typename) * data =
+      (@(message_typename) *)allocator.reallocate(
+      output->data, allocation_size, allocator.state);
+    if (!data) {
+      return false;
+    }
+    for (size_t i = output->capacity; i < input->size; ++i) {
+      if (!@(message_typename)__init(&data[i])) {
+        /* free currently allocated and return false */
+        for (; i-- > output->capacity; ) {
+          @(message_typename)__fini(&data[i]);
+        }
+        allocator.deallocate(data, allocator.state);
+        return false;
+      }
+    }
+    output->data = data;
+    output->size = input->size;
+    output->capacity = input->size;
+  }
+  for (size_t i = 0; i < input->size; ++i) {
+    if (!@(message_typename)__copy(
+        &(input->data[i]), &(output->data[i])))
+    {
+      return false;
+    }
+  }
+  return true;
+}
diff --git a/rosidl_generator_c/resource/msg__functions.h.em b/rosidl_generator_c/resource/msg__functions.h.em
index 8fa5e8eb5..15cd8b42e 100644
--- a/rosidl_generator_c/resource/msg__functions.h.em
+++ b/rosidl_generator_c/resource/msg__functions.h.em
@@ -69,6 +69,23 @@ ROSIDL_GENERATOR_C_PUBLIC_@(package_name)
 bool
 @(message_typename)__are_equal(const @(message_typename) * lhs, const @(message_typename) * rhs);
 
+/// Copy a @(interface_path_to_string(interface_path)) message.
+/**
+ * This functions performs a deep copy, as opposed to the shallow copy that
+ * plain assignment yields.
+ *
+ * \param[in] input The source message pointer.
+ * \param[out] output The target message pointer, which must
+ *   have been initialized before calling this function.
+ * \return true if successful, or false if either pointer is null
+ *   or memory allocation fails.
+ */
+ROSIDL_GENERATOR_C_PUBLIC_@(package_name)
+bool
+@(message_typename)__copy(
+  const @(message_typename) * input,
+  @(message_typename) * output);
+
 @#######################################################################
 @# array functions
 @#######################################################################
@@ -131,3 +148,20 @@ void
 ROSIDL_GENERATOR_C_PUBLIC_@(package_name)
 bool
 @(array_typename)__are_equal(const @(array_typename) * lhs, const @(array_typename) * rhs);
+
+/// Copy an array of @(interface_path_to_string(interface_path)) messages.
+/**
+ * This functions performs a deep copy, as opposed to the shallow copy that
+ * plain assignment yields.
+ *
+ * \param[in] input The source array pointer.
+ * \param[out] output The target array pointer, which must
+ *   have been initialized before calling this function.
+ * \return true if successful, or false if either pointer
+ *   is null or memory allocation fails.
+ */
+ROSIDL_GENERATOR_C_PUBLIC_@(package_name)
+bool
+@(array_typename)__copy(
+  const @(array_typename) * input,
+  @(array_typename) * output);
diff --git a/rosidl_generator_c/test/test_interfaces.c b/rosidl_generator_c/test/test_interfaces.c
index 54688a176..ab79527e4 100644
--- a/rosidl_generator_c/test/test_interfaces.c
+++ b/rosidl_generator_c/test/test_interfaces.c
@@ -202,6 +202,14 @@ int test_basic_types(void)
   EXPECT_FALSE(rosidl_generator_c__msg__BasicTypes__are_equal(NULL, basic));
   EXPECT_TRUE(rosidl_generator_c__msg__BasicTypes__are_equal(basic, basic));
 
+  rosidl_generator_c__msg__BasicTypes * basic_copy = NULL;
+  basic_copy = rosidl_generator_c__msg__BasicTypes__create();
+  EXPECT_NE(basic_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__BasicTypes__are_equal(basic, basic_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__BasicTypes__copy(basic, basic_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__BasicTypes__are_equal(basic, basic_copy));
+  rosidl_generator_c__msg__BasicTypes__destroy(basic_copy);
+
   rosidl_generator_c__msg__BasicTypes__destroy(basic);
   return 0;
 }
@@ -250,6 +258,15 @@ int test_defaults()
   EXPECT_FALSE(rosidl_generator_c__msg__Defaults__are_equal(NULL, def));
   EXPECT_TRUE(rosidl_generator_c__msg__Defaults__are_equal(def, def));
 
+  rosidl_generator_c__msg__Defaults * def_copy = NULL;
+  def_copy = rosidl_generator_c__msg__Defaults__create();
+  EXPECT_NE(def_copy, NULL);
+  def->bool_value = false;  // mutate message to force a difference
+  EXPECT_FALSE(rosidl_generator_c__msg__Defaults__are_equal(def, def_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Defaults__copy(def, def_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Defaults__are_equal(def, def_copy));
+  rosidl_generator_c__msg__Defaults__destroy(def_copy);
+
   rosidl_generator_c__msg__Defaults__destroy(def);
   return 0;
 }
@@ -470,6 +487,14 @@ int test_bounded_sequences()
   EXPECT_FALSE(rosidl_generator_c__msg__BoundedSequences__are_equal(NULL, seq));
   EXPECT_TRUE(rosidl_generator_c__msg__BoundedSequences__are_equal(seq, seq));
 
+  rosidl_generator_c__msg__BoundedSequences * seq_copy = NULL;
+  seq_copy = rosidl_generator_c__msg__BoundedSequences__create();
+  EXPECT_NE(seq_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__BoundedSequences__are_equal(seq, seq_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__BoundedSequences__copy(seq, seq_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__BoundedSequences__are_equal(seq, seq_copy));
+  rosidl_generator_c__msg__BoundedSequences__destroy(seq_copy);
+
   rosidl_generator_c__msg__BoundedSequences__destroy(seq);
   return 0;
 }
@@ -691,6 +716,14 @@ int test_unbounded_sequences()
   EXPECT_FALSE(rosidl_generator_c__msg__UnboundedSequences__are_equal(NULL, seq));
   EXPECT_TRUE(rosidl_generator_c__msg__UnboundedSequences__are_equal(seq, seq));
 
+  rosidl_generator_c__msg__UnboundedSequences * seq_copy = NULL;
+  seq_copy = rosidl_generator_c__msg__UnboundedSequences__create();
+  EXPECT_NE(seq_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__UnboundedSequences__are_equal(seq, seq_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__UnboundedSequences__copy(seq, seq_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__UnboundedSequences__are_equal(seq, seq_copy));
+  rosidl_generator_c__msg__UnboundedSequences__destroy(seq_copy);
+
   rosidl_generator_c__msg__UnboundedSequences__destroy(seq);
   return 0;
 }
@@ -727,6 +760,14 @@ int test_strings()
   EXPECT_FALSE(rosidl_generator_c__msg__Strings__are_equal(NULL, str));
   EXPECT_TRUE(rosidl_generator_c__msg__Strings__are_equal(str, str));
 
+  rosidl_generator_c__msg__Strings * str_copy = NULL;
+  str_copy = rosidl_generator_c__msg__Strings__create();
+  EXPECT_NE(str_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__Strings__are_equal(str, str_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Strings__copy(str, str_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Strings__are_equal(str, str_copy));
+  rosidl_generator_c__msg__Strings__destroy(str_copy);
+
   rosidl_generator_c__msg__Strings__destroy(str);
   return 0;
 }
@@ -770,6 +811,14 @@ int test_nested()
   EXPECT_FALSE(rosidl_generator_c__msg__Nested__are_equal(NULL, nested));
   EXPECT_TRUE(rosidl_generator_c__msg__Nested__are_equal(nested, nested));
 
+  rosidl_generator_c__msg__Nested * nested_copy = NULL;
+  nested_copy = rosidl_generator_c__msg__Nested__create();
+  EXPECT_NE(nested_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__Nested__are_equal(nested, nested_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Nested__copy(nested, nested_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Nested__are_equal(nested, nested_copy));
+  rosidl_generator_c__msg__Nested__destroy(nested_copy);
+
   rosidl_generator_c__msg__Nested__destroy(nested);
   return 0;
 }
@@ -1014,6 +1063,14 @@ int test_multi_nested()
   EXPECT_FALSE(rosidl_generator_c__msg__MultiNested__are_equal(NULL, msg));
   EXPECT_TRUE(rosidl_generator_c__msg__MultiNested__are_equal(msg, msg));
 
+  rosidl_generator_c__msg__MultiNested * msg_copy = NULL;
+  msg_copy = rosidl_generator_c__msg__MultiNested__create();
+  EXPECT_NE(msg_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__MultiNested__are_equal(msg, msg_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__MultiNested__copy(msg, msg_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__MultiNested__are_equal(msg, msg_copy));
+  rosidl_generator_c__msg__MultiNested__destroy(msg_copy);
+
   rosidl_generator_c__msg__MultiNested__destroy(msg);
   return 0;
 }
@@ -1230,6 +1287,14 @@ int test_arrays()
   EXPECT_FALSE(rosidl_generator_c__msg__Arrays__are_equal(NULL, arr));
   EXPECT_TRUE(rosidl_generator_c__msg__Arrays__are_equal(arr, arr));
 
+  rosidl_generator_c__msg__Arrays * arr_copy = NULL;
+  arr_copy = rosidl_generator_c__msg__Arrays__create();
+  EXPECT_NE(arr_copy, NULL);
+  EXPECT_FALSE(rosidl_generator_c__msg__Arrays__are_equal(arr, arr_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Arrays__copy(arr, arr_copy));
+  EXPECT_TRUE(rosidl_generator_c__msg__Arrays__are_equal(arr, arr_copy));
+  rosidl_generator_c__msg__Arrays__destroy(arr_copy);
+
   rosidl_generator_c__msg__Arrays__destroy(arr);
   return 0;
 }
diff --git a/rosidl_runtime_c/include/rosidl_runtime_c/primitives_sequence_functions.h b/rosidl_runtime_c/include/rosidl_runtime_c/primitives_sequence_functions.h
index 99f7f3ac0..4f8b1feaf 100644
--- a/rosidl_runtime_c/include/rosidl_runtime_c/primitives_sequence_functions.h
+++ b/rosidl_runtime_c/include/rosidl_runtime_c/primitives_sequence_functions.h
@@ -76,17 +76,36 @@ extern "C"
     const rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence * lhs, \
     const rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence * rhs);
 
+/**
+ * \def ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(STRUCT_NAME)
+ *
+ * \brief Copy the sequence.
+ *
+ * param input a pointer to the sequence to copy from
+ * param output a pointer to an initialized sequence to copy to
+ * return true if successful, false if either pointer is null or memory
+ *   allocation fails.
+ */
+#define ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(STRUCT_NAME) \
+  /** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(STRUCT_NAME) */ \
+  ROSIDL_GENERATOR_C_PUBLIC \
+  bool rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__copy( \
+    const rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence * input, \
+    rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence * output);
+
 /**
  * \def ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_FUNCTIONS(STRUCT_NAME)
  *
  * \brief See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_INIT(STRUCT_NAME),
- * #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_FINI(STRUCT_NAME), and
- * #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_EQ(STRUCT_NAME).
+ * #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_FINI(STRUCT_NAME),
+ * #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_EQ(STRUCT_NAME), and
+ * #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(STRUCT_NAME).
  */
 #define ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_FUNCTIONS(STRUCT_NAME) \
   ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_INIT(STRUCT_NAME) \
   ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_FINI(STRUCT_NAME) \
-  ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_EQ(STRUCT_NAME)
+  ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_EQ(STRUCT_NAME) \
+  ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(STRUCT_NAME)
 
 /**
  * \defgroup primitives_sequence_functions__basic_types Sequence functions for all basic types.
@@ -126,6 +145,11 @@ ROSIDL_GENERATOR_C_PUBLIC
 bool rosidl_runtime_c__bool__Sequence__are_equal(
   const rosidl_runtime_c__boolean__Sequence * lhs,
   const rosidl_runtime_c__boolean__Sequence * rhs);
+/** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(bool) */
+ROSIDL_GENERATOR_C_PUBLIC
+bool rosidl_runtime_c__bool__Sequence__copy(
+  const rosidl_runtime_c__boolean__Sequence * input,
+  rosidl_runtime_c__boolean__Sequence * output);
 
 /** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_INIT(byte) */
 ROSIDL_GENERATOR_C_PUBLIC
@@ -140,6 +164,11 @@ ROSIDL_GENERATOR_C_PUBLIC
 bool rosidl_runtime_c__byte__Sequence__are_equal(
   const rosidl_runtime_c__octet__Sequence * lhs,
   const rosidl_runtime_c__octet__Sequence * rhs);
+/** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(byte) */
+ROSIDL_GENERATOR_C_PUBLIC
+bool rosidl_runtime_c__byte__Sequence__copy(
+  const rosidl_runtime_c__octet__Sequence * input,
+  rosidl_runtime_c__octet__Sequence * output);
 
 /** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_INIT(float32) */
 ROSIDL_GENERATOR_C_PUBLIC
@@ -154,6 +183,11 @@ ROSIDL_GENERATOR_C_PUBLIC
 bool rosidl_runtime_c__float32__Sequence__are_equal(
   const rosidl_runtime_c__float__Sequence * lhs,
   const rosidl_runtime_c__float__Sequence * rhs);
+/** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(float32) */
+ROSIDL_GENERATOR_C_PUBLIC
+bool rosidl_runtime_c__float32__Sequence__copy(
+  const rosidl_runtime_c__float__Sequence * input,
+  rosidl_runtime_c__float__Sequence * output);
 
 /** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_INIT(float64) */
 ROSIDL_GENERATOR_C_PUBLIC
@@ -168,6 +202,11 @@ ROSIDL_GENERATOR_C_PUBLIC
 bool rosidl_runtime_c__float64__Sequence__are_equal(
   const rosidl_runtime_c__double__Sequence * lhs,
   const rosidl_runtime_c__double__Sequence * rhs);
+/** See #ROSIDL_RUNTIME_C__DECLARE_PRIMITIVE_SEQUENCE_COPY(float64) */
+ROSIDL_GENERATOR_C_PUBLIC
+bool rosidl_runtime_c__float64__Sequence__copy(
+  const rosidl_runtime_c__double__Sequence * input,
+  rosidl_runtime_c__double__Sequence * output);
 /**@}*/
 
 #ifdef __cplusplus
diff --git a/rosidl_runtime_c/include/rosidl_runtime_c/string_functions.h b/rosidl_runtime_c/include/rosidl_runtime_c/string_functions.h
index ef5b6ac2b..ef553df33 100644
--- a/rosidl_runtime_c/include/rosidl_runtime_c/string_functions.h
+++ b/rosidl_runtime_c/include/rosidl_runtime_c/string_functions.h
@@ -55,6 +55,24 @@ ROSIDL_GENERATOR_C_PUBLIC
 void
 rosidl_runtime_c__String__fini(rosidl_runtime_c__String * str);
 
+/// Copy rosidl_runtime_c__String structure content.
+/**
+ * This functions performs a deep copy, as opposed to the shallow copy that
+ * plain assignment yields.
+ *
+ * \param[in] input a pointer to a rosidl_runtime_c__String structure
+ *   to copy from.
+ * \param[out] output a pointer to an initialized rosidl_runtime_c__String
+ *   structure to copy into.
+ * \return true if successful, false if either pointer is null or memory
+ *   allocation fails.
+ */
+ROSIDL_GENERATOR_C_PUBLIC
+bool
+rosidl_runtime_c__String__copy(
+  const rosidl_runtime_c__String * input,
+  rosidl_runtime_c__String * output);
+
 /// Check for rosidl_runtime_c__String structure equality.
 /**
  * \param[in] lhs a pointer to the left hand side of the equality operator.
@@ -142,6 +160,24 @@ rosidl_runtime_c__String__Sequence__are_equal(
   const rosidl_runtime_c__String__Sequence * lhs,
   const rosidl_runtime_c__String__Sequence * rhs);
 
+/// Copy rosidl_runtime_c__String__Sequence structure content.
+/**
+ * This functions performs a deep copy, as opposed to the shallow copy
+ * that plain assignment yields.
+ *
+ * \param[in] input a pointer to a rosidl_runtime_c__String__Sequence
+ *   structure to copy from.
+ * \param[out] output a pointer to an initialized rosidl_runtime_c__String__Sequence
+ *   structure to copy into.
+ * \return true if successful, false if either pointer is null or memory
+ *   allocation fails.
+ */
+ROSIDL_GENERATOR_C_PUBLIC
+bool
+rosidl_runtime_c__String__Sequence__copy(
+  const rosidl_runtime_c__String__Sequence * input,
+  rosidl_runtime_c__String__Sequence * output);
+
 /// Create a rosidl_runtime_c__String__Sequence structure with a specific size.
 /*
  * The string sequence initially has size and capacity equal to the size argument passed to the
diff --git a/rosidl_runtime_c/include/rosidl_runtime_c/u16string_functions.h b/rosidl_runtime_c/include/rosidl_runtime_c/u16string_functions.h
index 6ddfe8a3f..c89afabfc 100644
--- a/rosidl_runtime_c/include/rosidl_runtime_c/u16string_functions.h
+++ b/rosidl_runtime_c/include/rosidl_runtime_c/u16string_functions.h
@@ -67,6 +67,24 @@ rosidl_runtime_c__U16String__are_equal(
   const rosidl_runtime_c__U16String * lhs,
   const rosidl_runtime_c__U16String * rhs);
 
+/// Copy rosidl_runtime_c__U16String structure content.
+/**
+ * This functions performs a deep copy, as opposed to the shallow copy that
+ * plain assignment yields.
+ *
+ * \param[in] input a pointer to a rosidl_runtime_c__U16String structure
+ *   to copy from.
+ * \param[out] output a pointer to an initialized rosidl_runtime_c__U16String
+ *   structure to copy into.
+ * \return true if successful, false if either pointer is null or memory
+ *   allocation fails.
+ */
+ROSIDL_GENERATOR_C_PUBLIC
+bool
+rosidl_runtime_c__U16String__copy(
+  const rosidl_runtime_c__U16String * input,
+  rosidl_runtime_c__U16String * output);
+
 /// Assign the uint16_t value of n characters to the rosidl_runtime_c__U16String structure.
 /*
  * This function returns `false` if memory cannot be allocated,
@@ -190,6 +208,24 @@ rosidl_runtime_c__U16String__Sequence__are_equal(
   const rosidl_runtime_c__U16String__Sequence * lhs,
   const rosidl_runtime_c__U16String__Sequence * rhs);
 
+/// Copy a U16 string sequence content.
+/**
+ * This functions performs a deep copy, as opposed to the shallow copy
+ * that plain assignment yields.
+ *
+ * \param[in] input a pointer to a rosidl_runtime_c__String__Sequence
+ *   structure to copy from.
+ * \param[out] output a pointer to an initialized rosidl_runtime_c__String__Sequence
+ *   structure to copy into.
+ * \return true if successful, false if either pointer is null or memory
+ *   allocation fails.
+ */
+ROSIDL_GENERATOR_C_PUBLIC
+bool
+rosidl_runtime_c__U16String__Sequence__copy(
+  const rosidl_runtime_c__U16String__Sequence * input,
+  rosidl_runtime_c__U16String__Sequence * output);
+
 /// Create a U16 string sequence structure with a specific size.
 /*
  * The U16 string sequence initially has size and capacity equal to the size
diff --git a/rosidl_runtime_c/src/primitives_sequence_functions.c b/rosidl_runtime_c/src/primitives_sequence_functions.c
index 6351f9ba6..784e20773 100644
--- a/rosidl_runtime_c/src/primitives_sequence_functions.c
+++ b/rosidl_runtime_c/src/primitives_sequence_functions.c
@@ -15,6 +15,7 @@
 #include <assert.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "rosidl_runtime_c/primitives_sequence_functions.h"
 
@@ -74,6 +75,28 @@
       } \
     } \
     return true; \
+  } \
+ \
+  bool rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__copy( \
+    const rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence * input, \
+    rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence * output) \
+  { \
+    if (!input || !output) { \
+      return false; \
+    } \
+    if (output->capacity < input->size) { \
+      rcutils_allocator_t allocator = rcutils_get_default_allocator(); \
+      TYPE_NAME * data = (TYPE_NAME *)allocator.reallocate( \
+        output->data, sizeof(TYPE_NAME) * input->size, allocator.state); \
+      if (!data) { \
+        return false; \
+      } \
+      output->data = data; \
+      output->capacity = input->size; \
+    } \
+    memcpy(output->data, input->data, sizeof(TYPE_NAME) * input->size); \
+    output->size = input->size; \
+    return true; \
   }
 
 
@@ -113,6 +136,12 @@ bool rosidl_runtime_c__bool__Sequence__are_equal(
 {
   return rosidl_runtime_c__boolean__Sequence__are_equal(lhs, rhs);
 }
+bool rosidl_runtime_c__bool__Sequence__copy(
+  const rosidl_runtime_c__boolean__Sequence * input,
+  rosidl_runtime_c__boolean__Sequence * output)
+{
+  return rosidl_runtime_c__boolean__Sequence__copy(input, output);
+}
 
 bool rosidl_runtime_c__byte__Sequence__init(
   rosidl_runtime_c__octet__Sequence * sequence, size_t size)
@@ -132,6 +161,12 @@ bool rosidl_runtime_c__byte__Sequence__are_equal(
 {
   return rosidl_runtime_c__octet__Sequence__are_equal(lhs, rhs);
 }
+bool rosidl_runtime_c__byte__Sequence__copy(
+  const rosidl_runtime_c__octet__Sequence * input,
+  rosidl_runtime_c__octet__Sequence * output)
+{
+  return rosidl_runtime_c__octet__Sequence__copy(input, output);
+}
 
 bool rosidl_runtime_c__float32__Sequence__init(
   rosidl_runtime_c__float__Sequence * sequence, size_t size)
@@ -151,6 +186,12 @@ bool rosidl_runtime_c__float32__Sequence__are_equal(
 {
   return rosidl_runtime_c__float__Sequence__are_equal(lhs, rhs);
 }
+bool rosidl_runtime_c__float32__Sequence__copy(
+  const rosidl_runtime_c__float__Sequence * input,
+  rosidl_runtime_c__float__Sequence * output)
+{
+  return rosidl_runtime_c__float__Sequence__copy(input, output);
+}
 
 bool rosidl_runtime_c__float64__Sequence__init(
   rosidl_runtime_c__double__Sequence * sequence, size_t size)
@@ -170,3 +211,9 @@ bool rosidl_runtime_c__float64__Sequence__are_equal(
 {
   return rosidl_runtime_c__double__Sequence__are_equal(lhs, rhs);
 }
+bool rosidl_runtime_c__float64__Sequence__copy(
+  const rosidl_runtime_c__double__Sequence * input,
+  rosidl_runtime_c__double__Sequence * output)
+{
+  return rosidl_runtime_c__double__Sequence__copy(input, output);
+}
diff --git a/rosidl_runtime_c/src/string_functions.c b/rosidl_runtime_c/src/string_functions.c
index cc8330be1..e8bf8cdb1 100644
--- a/rosidl_runtime_c/src/string_functions.c
+++ b/rosidl_runtime_c/src/string_functions.c
@@ -127,6 +127,18 @@ rosidl_runtime_c__String__assign(
     str, value, strlen(value));
 }
 
+bool
+rosidl_runtime_c__String__copy(
+  const rosidl_runtime_c__String * input,
+  rosidl_runtime_c__String * output)
+{
+  if (!input) {
+    return false;
+  }
+  return rosidl_runtime_c__String__assignn(
+    output, input->data, input->size);
+}
+
 bool
 rosidl_runtime_c__String__Sequence__init(
   rosidl_runtime_c__String__Sequence * sequence, size_t size)
@@ -206,6 +218,48 @@ rosidl_runtime_c__String__Sequence__are_equal(
   return true;
 }
 
+bool
+rosidl_runtime_c__String__Sequence__copy(
+  const rosidl_runtime_c__String__Sequence * input,
+  rosidl_runtime_c__String__Sequence * output)
+{
+  if (!input || !output) {
+    return false;
+  }
+  if (output->capacity < input->size) {
+    const size_t allocation_size =
+      input->size * sizeof(rosidl_runtime_c__String);
+    rcutils_allocator_t allocator = rcutils_get_default_allocator();
+    rosidl_runtime_c__String * data =
+      (rosidl_runtime_c__String *)allocator.reallocate(
+      output->data, allocation_size, allocator.state);
+    if (!data) {
+      return false;
+    }
+    for (size_t i = output->capacity; i < input->size; ++i) {
+      if (!rosidl_runtime_c__String__init(&data[i])) {
+        /* free currently allocated and return false */
+        for (; i-- > output->capacity; ) {
+          rosidl_runtime_c__String__fini(&data[i]);
+        }
+        allocator.deallocate(data, allocator.state);
+        return false;
+      }
+    }
+    output->data = data;
+    output->size = input->size;
+    output->capacity = input->size;
+  }
+  for (size_t i = 0; i < input->size; ++i) {
+    if (!rosidl_runtime_c__String__copy(
+        &(input->data[i]), &(output->data[i])))
+    {
+      return false;
+    }
+  }
+  return true;
+}
+
 rosidl_runtime_c__String__Sequence *
 rosidl_runtime_c__String__Sequence__create(size_t size)
 {
diff --git a/rosidl_runtime_c/src/u16string_functions.c b/rosidl_runtime_c/src/u16string_functions.c
index eae6bd3eb..88e585ec9 100644
--- a/rosidl_runtime_c/src/u16string_functions.c
+++ b/rosidl_runtime_c/src/u16string_functions.c
@@ -135,6 +135,18 @@ rosidl_runtime_c__U16String__assign(
     str, value, rosidl_runtime_c__U16String__len(value));
 }
 
+bool
+rosidl_runtime_c__U16String__copy(
+  const rosidl_runtime_c__U16String * input,
+  rosidl_runtime_c__U16String * output)
+{
+  if (!input) {
+    return false;
+  }
+  return rosidl_runtime_c__U16String__assignn(
+    output, input->data, input->size);
+}
+
 size_t
 rosidl_runtime_c__U16String__len(const uint16_t * value)
 {
@@ -249,6 +261,49 @@ rosidl_runtime_c__U16String__Sequence__are_equal(
   return true;
 }
 
+bool
+rosidl_runtime_c__U16String__Sequence__copy(
+  const rosidl_runtime_c__U16String__Sequence * input,
+  rosidl_runtime_c__U16String__Sequence * output)
+{
+  if (!input || !output) {
+    return false;
+  }
+  if (output->capacity < input->size) {
+    const size_t size =
+      input->size * sizeof(rosidl_runtime_c__U16String);
+    rcutils_allocator_t allocator = rcutils_get_default_allocator();
+    rosidl_runtime_c__U16String * data =
+      (rosidl_runtime_c__U16String *)allocator.reallocate(
+      output->data, size, allocator.state);
+    if (!data) {
+      return false;
+    }
+    for (size_t i = output->capacity; i < input->size; ++i) {
+      if (!rosidl_runtime_c__U16String__init(&data[i])) {
+        /* free currently allocated and return false */
+        for (; i-- > output->capacity; ) {
+          rosidl_runtime_c__U16String__fini(&data[i]);
+        }
+        allocator.deallocate(data, allocator.state);
+        return false;
+      }
+    }
+    output->data = data;
+    output->size = input->size;
+    output->capacity = input->size;
+  }
+  for (size_t i = 0; i < input->size; ++i) {
+    if (!rosidl_runtime_c__U16String__copy(
+        &(input->data[i]), &(output->data[i])))
+    {
+      return false;
+    }
+  }
+  return true;
+}
+
+
 rosidl_runtime_c__U16String__Sequence *
 rosidl_runtime_c__U16String__Sequence__create(size_t size)
 {
diff --git a/rosidl_runtime_c/test/test_primitives_sequence_functions.cpp b/rosidl_runtime_c/test/test_primitives_sequence_functions.cpp
index bb171224f..93c916a2d 100644
--- a/rosidl_runtime_c/test/test_primitives_sequence_functions.cpp
+++ b/rosidl_runtime_c/test/test_primitives_sequence_functions.cpp
@@ -81,6 +81,23 @@
     rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__fini(&nonzero_initialized); \
     rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__fini(&zero_initialized); \
     rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__fini(&empty); \
+  } \
+ \
+  TEST(primitives_sequence_functions, test_ ## STRUCT_NAME ## _copy) \
+  { \
+    rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence input, output; \
+    EXPECT_FALSE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__copy(nullptr, nullptr)); \
+    EXPECT_FALSE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__copy(nullptr, &output)); \
+    EXPECT_FALSE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__copy(&input, nullptr)); \
+ \
+    EXPECT_TRUE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__init(&input, 1u)); \
+    input.data[0] = (TYPE_NAME)1; \
+    EXPECT_TRUE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__init(&output, 0u)); \
+    EXPECT_FALSE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__are_equal(&input, &output)); \
+    EXPECT_TRUE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__copy(&input, &output)); \
+    EXPECT_TRUE(rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__are_equal(&input, &output)); \
+    rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__fini(&output); \
+    rosidl_runtime_c__ ## STRUCT_NAME ## __Sequence__fini(&input); \
   }
 
 TEST_PRIMITIVE_SEQUENCE_FUNCTIONS(float, float)
diff --git a/rosidl_runtime_c/test/test_string_functions.cpp b/rosidl_runtime_c/test/test_string_functions.cpp
index 20ecfcf0d..f3da91c58 100644
--- a/rosidl_runtime_c/test/test_string_functions.cpp
+++ b/rosidl_runtime_c/test/test_string_functions.cpp
@@ -142,6 +142,25 @@ TEST(string_functions, equality_comparison) {
   rosidl_runtime_c__String__fini(&empty_string);
 }
 
+TEST(string_functions, copy) {
+  rosidl_runtime_c__String input, output;
+
+  EXPECT_FALSE(rosidl_runtime_c__String__copy(nullptr, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__String__copy(&input, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__String__copy(nullptr, &output));
+
+  EXPECT_TRUE(rosidl_runtime_c__String__init(&input));
+  EXPECT_TRUE(rosidl_runtime_c__String__assign(&input, "foo"));
+  EXPECT_TRUE(rosidl_runtime_c__String__init(&output));
+
+  EXPECT_FALSE(rosidl_runtime_c__String__are_equal(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__String__copy(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__String__are_equal(&input, &output));
+
+  rosidl_runtime_c__String__fini(&output);
+  rosidl_runtime_c__String__fini(&input);
+}
+
 TEST(string_functions, init_fini_sequence) {
   rosidl_runtime_c__String__Sequence sequence;
   EXPECT_FALSE(rosidl_runtime_c__String__Sequence__init(nullptr, 0u));
@@ -215,3 +234,22 @@ TEST(string_functions, sequence_equality_comparison) {
   rosidl_runtime_c__String__Sequence__fini(&empty_sequence);
   rosidl_runtime_c__String__Sequence__fini(&nonempty_sequence);
 }
+
+TEST(string_functions, copy_sequence) {
+  rosidl_runtime_c__String__Sequence input, output;
+
+  EXPECT_FALSE(rosidl_runtime_c__String__Sequence__copy(nullptr, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__String__Sequence__copy(&input, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__String__Sequence__copy(nullptr, &output));
+
+  EXPECT_TRUE(rosidl_runtime_c__String__Sequence__init(&input, 1u));
+  EXPECT_TRUE(rosidl_runtime_c__String__assign(&input.data[0], "foo"));
+  EXPECT_TRUE(rosidl_runtime_c__String__Sequence__init(&output, 0u));
+
+  EXPECT_FALSE(rosidl_runtime_c__String__Sequence__are_equal(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__String__Sequence__copy(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__String__Sequence__are_equal(&input, &output));
+
+  rosidl_runtime_c__String__Sequence__fini(&output);
+  rosidl_runtime_c__String__Sequence__fini(&input);
+}
diff --git a/rosidl_runtime_c/test/test_u16string_functions.cpp b/rosidl_runtime_c/test/test_u16string_functions.cpp
index 834155945..f44088048 100644
--- a/rosidl_runtime_c/test/test_u16string_functions.cpp
+++ b/rosidl_runtime_c/test/test_u16string_functions.cpp
@@ -174,6 +174,26 @@ TEST(u16string_functions, equality_comparison) {
   rosidl_runtime_c__U16String__fini(&empty_string);
 }
 
+TEST(u16string_functions, copy) {
+  rosidl_runtime_c__U16String input, output;
+
+  EXPECT_FALSE(rosidl_runtime_c__U16String__copy(nullptr, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__U16String__copy(&input, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__U16String__copy(nullptr, &output));
+
+  EXPECT_TRUE(rosidl_runtime_c__U16String__init(&input));
+  const uint16_t encoded_foo_string[] = {102u, 111u, 111u, 0u};
+  EXPECT_TRUE(rosidl_runtime_c__U16String__assign(&input, encoded_foo_string));
+  EXPECT_TRUE(rosidl_runtime_c__U16String__init(&output));
+
+  EXPECT_FALSE(rosidl_runtime_c__U16String__are_equal(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__U16String__copy(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__U16String__are_equal(&input, &output));
+
+  rosidl_runtime_c__U16String__fini(&output);
+  rosidl_runtime_c__U16String__fini(&input);
+}
+
 TEST(u16string_functions, init_fini_sequence) {
   rosidl_runtime_c__U16String__Sequence sequence;
   EXPECT_FALSE(rosidl_runtime_c__U16String__Sequence__init(nullptr, 0u));
@@ -253,3 +273,23 @@ TEST(u16string_functions, sequence_equality_comparison) {
   rosidl_runtime_c__U16String__Sequence__fini(&empty_sequence);
   rosidl_runtime_c__U16String__Sequence__fini(&nonempty_sequence);
 }
+
+TEST(u16string_functions, copy_sequence) {
+  rosidl_runtime_c__U16String__Sequence input, output;
+
+  EXPECT_FALSE(rosidl_runtime_c__U16String__Sequence__copy(nullptr, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__U16String__Sequence__copy(&input, nullptr));
+  EXPECT_FALSE(rosidl_runtime_c__U16String__Sequence__copy(nullptr, &output));
+
+  EXPECT_TRUE(rosidl_runtime_c__U16String__Sequence__init(&input, 1u));
+  const uint16_t encoded_foo_string[] = {102u, 111u, 111u, 0u};
+  EXPECT_TRUE(rosidl_runtime_c__U16String__assign(&input.data[0], encoded_foo_string));
+  EXPECT_TRUE(rosidl_runtime_c__U16String__Sequence__init(&output, 0u));
+
+  EXPECT_FALSE(rosidl_runtime_c__U16String__Sequence__are_equal(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__U16String__Sequence__copy(&input, &output));
+  EXPECT_TRUE(rosidl_runtime_c__U16String__Sequence__are_equal(&input, &output));
+
+  rosidl_runtime_c__U16String__Sequence__fini(&output);
+  rosidl_runtime_c__U16String__Sequence__fini(&input);
+}