Fix std::fill templating

rosidl_generator_cpp/resource/msg__struct.hpp.em

@@ -5,6 +5,8 @@ from rosidl_generator_cpp import escape_string
 from rosidl_generator_cpp import escape_wstring
 from rosidl_generator_cpp import msg_type_to_cpp
 from rosidl_generator_cpp import MSG_TYPE_TO_CPP
+from rosidl_generator_cpp import generate_zero_string
+from rosidl_generator_cpp import generate_default_string
 from rosidl_parser.definition import AbstractNestedType
 from rosidl_parser.definition import AbstractString
 from rosidl_parser.definition import AbstractWString
@@ -108,48 +110,6 @@ struct @(message.structure.namespaced_type.name)_
 # http://design.ros2.org/articles/generated_interfaces_cpp.html#constructors
 # for a detailed explanation of the different _init parameters.
 init_list, alloc_list, member_list = create_init_alloc_and_member_lists(message)
-
-def generate_default_string(membset):
-    from rosidl_generator_cpp import msg_type_only_to_cpp
-    from rosidl_generator_cpp import msg_type_to_cpp
-    strlist = []
-    for member in membset.members:
-        if member.default_value is not None:
-            if member.num_prealloc > 0:
-                strlist.append('this->%s.resize(%d);' % (member.name, member.num_prealloc))
-            if isinstance(member.default_value, list):
-                if all(v == member.default_value[0] for v in member.default_value):
-                    # Specifying type for std::fill because of MSVC 14.12 warning about casting 'const int' to smaller types (C4244)
-                    # For more info, see https://github.com/ros2/rosidl/issues/309
-                    # TODO(jacobperron): Investigate reason for build warnings on Windows
-                    # TODO(jacobperron): Write test case for this path of execution
-                    strlist.append('std::fill<typename %s::iterator, %s>(this->%s.begin(), this->%s.end(), %s);' % (msg_type_to_cpp(member.type), msg_type_only_to_cpp(member.type), member.name, member.name, member.default_value[0]))
-                else:
-                    for index, val in enumerate(member.default_value):
-                        strlist.append('this->%s[%d] = %s;' % (member.name, index, val))
-            else:
-                strlist.append('this->%s = %s;' % (member.name, member.default_value))
-
-    return strlist
-
-def generate_zero_string(membset, fill_args):
-    from rosidl_generator_cpp import msg_type_only_to_cpp
-    from rosidl_generator_cpp import msg_type_to_cpp
-    strlist = []
-    for member in membset.members:
-        if isinstance(member.zero_value, list):
-            if member.num_prealloc > 0:
-                strlist.append('this->%s.resize(%d);' % (member.name, member.num_prealloc))
-            if member.zero_need_array_override:
-                strlist.append('this->%s.fill(%s{%s});' % (member.name, msg_type_only_to_cpp(member.type), fill_args))
-            else:
-                # Specifying type for std::fill because of MSVC 14.12 warning about casting 'const int' to smaller types (C4244)
-                # For more info, see https://github.com/ros2/rosidl/issues/309
-                # TODO(jacobperron): Investigate reason for build warnings on Windows
-                strlist.append('std::fill<typename %s::iterator, %s>(this->%s.begin(), this->%s.end(), %s);' % (msg_type_to_cpp(member.type), msg_type_only_to_cpp(member.type), member.name, member.name, member.zero_value[0]))
-        else:
-            strlist.append('this->%s = %s;' % (member.name, member.zero_value))
-    return strlist
 }@
   explicit @(message.structure.namespaced_type.name)_(rosidl_runtime_cpp::MessageInitialization _init = rosidl_runtime_cpp::MessageInitialization::ALL)
 @[if init_list]@

rosidl_generator_cpp/rosidl_generator_cpp/__init__.py

@@ -56,7 +56,7 @@ def prefix_with_bom_if_necessary(content: str) -> str:
 MSG_TYPE_TO_CPP = {
     'boolean': 'bool',
     'octet': 'unsigned char',  # TODO change to std::byte with C++17
-    'char': 'unsigned char',
+    'char': 'unsigned char',  # TODO change to char8_t with C++20
     'wchar': 'char16_t',
     'float': 'float',
     'double': 'double',
@@ -196,11 +196,15 @@ def primitive_value_to_cpp(type_, value):
     if type_.typename == 'boolean':
         return 'true' if value else 'false'
 
+    if type_.typename in [
+        'char', 'octet'
+    ]:
+        return f'static_cast<unsigned char>({value})'
+
     if type_.typename in [
         'short', 'unsigned short',
-        'char', 'wchar',
+        'wchar',
         'double', 'long double',
-        'octet',
         'int8', 'uint8',
         'int16', 'uint16',
     ]:
@@ -343,3 +347,44 @@ def add_member(self, member):
                 member_list.append(commonset)
 
     return init_list, alloc_list, member_list
+
+
+def generate_default_string(membset: list) -> list[str]:
+    strlist: list[str] = []
+    for member in membset.members:
+        if member.default_value is not None:
+            if member.num_prealloc > 0:
+                strlist.append('this->%s.resize(%d);' % (member.name, member.num_prealloc))
+            if isinstance(member.default_value, list):
+                if all(v == member.default_value[0] for v in member.default_value):
+                    strlist.append(
+                        'std::fill(this->%s.begin(), this->%s.end(), %s);' % (
+                            member.name,
+                            member.name,
+                            member.default_value[0]
+                            )
+                        )
+                else:
+                    for index, val in enumerate(member.default_value):
+                        strlist.append('this->%s[%d] = %s;' % (member.name, index, val))
+            else:
+                strlist.append('this->%s = %s;' % (member.name, member.default_value))
+
+    return strlist
+
+
+def generate_zero_string(membset: list, fill_args: str) -> list[str]:
+    strlist: list[str] = []
+    for member in membset.members:
+        if isinstance(member.zero_value, list):
+            if member.num_prealloc > 0:
+                strlist.append('this->%s.resize(%d);' % (member.name, member.num_prealloc))
+            if member.zero_need_array_override:
+                strlist.append('this->%s.fill(%s{%s});' % (
+                    member.name, msg_type_only_to_cpp(member.type), fill_args))
+            else:
+                strlist.append('std::fill(this->%s.begin(), this->%s.end(), %s);' % (
+                    member.name, member.name, member.zero_value[0]))
+        else:
+            strlist.append('this->%s = %s;' % (member.name, member.zero_value))
+    return strlist