C++20 compatibility.

Author: StefanFabian

ros_babel_fish/CMakeLists.txt

@@ -1,6 +1,9 @@
 cmake_minimum_required(VERSION 3.5)
-project(ros_babel_fish VERSION 3.25.2)
-set(CMAKE_CXX_STANDARD 17)
+project(ros_babel_fish VERSION 4.26.43)
+# Default to C++20
+if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 20)
+endif()
 
 # If the value doesn't fit, an exception is thrown in any case because that could result in unexpected behavior and can not be ignored lightly
 option(WARN_ON_INCOMPATIBLE_TYPE "If ON a warning is printed if a value message is set or accessed with a type that does not allow casting without loss of information" ON)

ros_babel_fish/examples/any_subscriber.cpp

@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 #include <chrono>
+#include <cstdint>
 #include <geometry_msgs/msg/point.hpp>
 #include <geometry_msgs/msg/point32.hpp>
 #include <rclcpp/rclcpp.hpp>
@@ -117,6 +118,20 @@ void printToStdOut<uint8_t>( const uint8_t &val )
   std::cout << static_cast<int>( val ); // Cast to int for proper displaying
 }
 
+template<>
+void printToStdOut<char16_t>( const char16_t &val )
+{
+  // std::ostream << char16_t is deleted in C++20 for narrow streams.
+  std::cout << static_cast<std::uint_least16_t>( val );
+}
+
+template<>
+void printToStdOut<char32_t>( const char32_t &val )
+{
+  // std::ostream << char32_t is deleted in C++20 for narrow streams.
+  std::cout << static_cast<std::uint_least32_t>( val );
+}
+
 template<typename T>
 void printArray( const T &message, const std::string & )
 {

ros_babel_fish_tools/CMakeLists.txt

@@ -1,6 +1,9 @@
 cmake_minimum_required(VERSION 3.5)
-project(ros_babel_fish_tools VERSION 0.1.0)
-set(CMAKE_CXX_STANDARD 17)
+project(ros_babel_fish_tools VERSION 4.26.43)
+# Default to C++20
+if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 20)
+endif()
 
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   add_compile_options(-Wall -Wextra -Wpedantic)

ros_babel_fish_tools/test/nlohmann_json_serialization.cpp

@@ -399,14 +399,15 @@ TEST_F( JsonSerializationTest, supplementaryUnicode )
 {
   auto msg = fish.create_message_shared( "ros_babel_fish_test_msgs/msg/TestMessage" );
   // U+1F600 GRINNING FACE — requires 4-byte UTF-8
-  ( *msg )["str"] = std::string( u8"\U0001F600" );
+  const std::string emoji_utf8 = "\xF0\x9F\x98\x80";
+  ( *msg )["str"] = emoji_utf8;
 
   json j = compound_message_to_json( *msg );
-  EXPECT_EQ( j["str"].get<std::string>(), u8"\U0001F600" );
+  EXPECT_EQ( j["str"].get<std::string>(), emoji_utf8 );
 
   auto msg2 = fish.create_message_shared( "ros_babel_fish_test_msgs/msg/TestMessage" );
   json_to_message( j, *msg2 );
-  EXPECT_EQ( ( *msg2 )["str"].value<std::string>(), u8"\U0001F600" );
+  EXPECT_EQ( ( *msg2 )["str"].value<std::string>(), emoji_utf8 );
 }
 
 TEST_F( JsonSerializationTest, boundedArrayThrows )