Deprecate parameter_traits package and header file (#297)

Author: christophfroehlich

generate_parameter_library_py/generate_parameter_library_py/jinja_templates/cpp/parameter_library_header

@@ -21,7 +21,10 @@
 #include <fmt/format.h>
 #include <fmt/ranges.h>
 
+// silence deprecation warnings for parameter_traits, needed for backwards compatibility
+#define SILENCE_DEPRECATION_WARNINGS
 #include <parameter_traits/parameter_traits.hpp>
+#undef SILENCE_DEPRECATION_WARNINGS
 
 #include <rsl/static_string.hpp>
 #include <rsl/static_vector.hpp>

parameter_traits/include/parameter_traits/parameter_traits.hpp

@@ -36,6 +36,19 @@
 #include <rsl/algorithm.hpp>
 #include <tl_expected/expected.hpp>
 
+#ifndef SILENCE_DEPRECATION_WARNINGS
+#ifdef _MSC_VER
+#pragma message( \
+    "This header is obsolete, \
+  please include \"rsl/algorithm.hpp\" for rsl::contains and rsl::is_unique, \
+  and \"tl_expected/expected.hpp\" for tl::expected.")
+#else
+#warning This header is obsolete, \
+  please include "rsl/algorithm.hpp" for rsl::contains and rsl::is_unique, \
+  and "tl_expected/expected.hpp" for tl::expected.
+#endif
+#endif
+
 namespace parameter_traits {
 
 using Result

parameter_traits/package.xml

@@ -23,5 +23,11 @@
 
   <export>
     <build_type>ament_cmake</build_type>
+    <export>
+    <deprecated>
+      This package will be removed in Lyrical Luth. Instead, use the
+      rsl or tl_expected packages directly for similar functionality.
+    </deprecated>
+</export>
   </export>
 </package>