2 files changed, 26 insertions, 15 deletions

diff --git a/src/openvic-simulation/utility/Getters.hpp b/src/openvic-simulation/utility/Getters.hpp
index 33aa5a2..fa76e74 100644
--- a/src/openvic-simulation/utility/Getters.hpp
+++ b/src/openvic-simulation/utility/Getters.hpp
@@ -51,13 +51,15 @@ public: \
 ACCESS:
 
 namespace OpenVic {
-	/* Any struct extending ReturnByValueProperty will be returned by value by PROPERTY-generated getter functions,
+	/* Any struct tagged with ov_return_by_value will be returned by value by PROPERTY-generated getter functions,
 	 * instead of by const reference as structs are by default. Use this for small structs which don't contain any
-	 * dynamically allocated memory, e.g. Date and fixed_point_t. */
-	struct ReturnByValueProperty {
-		constexpr bool operator==(ReturnByValueProperty const&) const = default;
-		constexpr std::strong_ordering operator<=>(ReturnByValueProperty const&) const = default;
-	};
+	 * dynamically allocated memory, e.g. dates and colours. The tag must be public, as in the example below:
+	 *
+	 * public:
+	 *     using ov_return_by_value = void;
+	 */
+	template<typename T>
+	concept ReturnByValue = requires { typename T::ov_return_by_value; };
 
 	/*
 	 * Template function used to choose the return type and provide the implementation
@@ -72,7 +74,7 @@ namespace OpenVic {
 			/* Return std::string_view looking at std::string */
 			return std::string_view { property };
 		} else if constexpr (
-			std::integral<T> || std::floating_point<T> || std::is_enum_v<T> || std::derived_from<T, ReturnByValueProperty>
+			std::integral<T> || std::floating_point<T> || std::is_enum_v<T> || ReturnByValue<T>
 		) {
 			/* Return value */
 			return T { property };
diff --git a/src/openvic-simulation/utility/Logger.hpp b/src/openvic-simulation/utility/Logger.hpp
index 53decb3..7a2c3d0 100644
--- a/src/openvic-simulation/utility/Logger.hpp
+++ b/src/openvic-simulation/utility/Logger.hpp
@@ -75,16 +75,16 @@ namespace OpenVic {
 			size_t message_count;
 		};
 
-		template<typename... Ts>
+		template<typename... Args>
 		struct log {
-			log(log_channel_t& log_channel, Ts&&... ts, source_location const& location) {
+			log(log_channel_t& log_channel, Args&&... args, source_location const& location) {
 				std::stringstream stream;
 				stream << StringUtils::get_filename(location.file_name()) << "("
 					/* Function name removed to reduce clutter. It is already included
 					* in Godot's print functions, so this was repeating it. */
 					//<< location.line() << ") `" << location.function_name() << "`: ";
 					<< location.line() << "): ";
-				((stream << std::forward<Ts>(ts)), ...);
+				((stream << std::forward<Args>(args)), ...);
 				stream << std::endl;
 				log_channel.queue.push(stream.str());
 				if (log_channel.func) {
@@ -109,19 +109,28 @@ public: \
 	static inline size_t get_##name##_count() { \
 		return name##_channel.message_count; \
 	} \
-	template<typename... Ts> \
+	template<typename... Args> \
 	struct name { \
-		name(Ts&&... ts, source_location const& location = source_location::current()) { \
-			log<Ts...> { name##_channel, std::forward<Ts>(ts)..., location }; \
+		name(Args&&... args, source_location const& location = source_location::current()) { \
+			log<Args...> { name##_channel, std::forward<Args>(args)..., location }; \
 		} \
 	}; \
-	template<typename... Ts> \
-	name(Ts&&...) -> name<Ts...>;
+	template<typename... Args> \
+	name(Args&&...) -> name<Args...>;
 
 		LOG_FUNC(info)
 		LOG_FUNC(warning)
 		LOG_FUNC(error)
 
 #undef LOG_FUNC
+
+		template<typename... Args>
+		static inline constexpr void warn_or_error(bool warn, Args&&... args) {
+			if (warn) {
+				warning(std::forward<Args>(args)...);
+			} else {
+				error(std::forward<Args>(args)...);
+			}
+		}
 	};
 }