History loading changes + PROPERTY macro

1 files changed, 66 insertions, 0 deletions

diff --git a/src/openvic-simulation/utility/Getters.hpp b/src/openvic-simulation/utility/Getters.hpp
new file mode 100644
index 0000000..c8f2193
--- /dev/null
+++ b/src/openvic-simulation/utility/Getters.hpp
@@ -0,0 +1,66 @@
+#pragma once
+
+#include <concepts>
+#include <string>
+#include <string_view>
+
+#define REF_GETTERS(var) \
+	constexpr decltype(var)& get_##var() { \
+		return var; \
+	} \
+	constexpr decltype(var) const& get_##var() const { \
+		return var; \
+	}
+
+namespace OpenVic {
+	struct ReturnByValueProperty {};
+
+	/*
+	 * Template function used to choose the return type and provide the implementation for the
+	 * for variable getters created using the PROPERTY macro.
+	 */
+	template<typename decl, typename T>
+	inline constexpr decltype(auto) _get_property(const T& property) {
+		if constexpr(std::is_reference_v<decl>) {
+			/* Return const reference */
+			return property;
+		} else if constexpr (std::same_as<T, std::string>) {
+			/* 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<T>::value || std::derived_from<T, ReturnByValueProperty>
+		) {
+			/* Return value */
+			return T { property };
+		} else if constexpr(std::is_pointer<T>::value) {
+			/* Return const pointer */
+			return static_cast<std::add_pointer_t<std::add_const_t<std::remove_pointer_t<T>>>>(property);
+		} else {
+			/* Return const reference */
+			return property;
+		}
+	}
+
+/*
+ * Use this on a variable delcaration to generate a getter function. It assumes the variable is private and so
+ * sets the accessibility modifier state back to private after declaring the getter as public.
+ * Examples:
+ * 		int PROPERTY(x);					// int x;						int get_x() const;
+ * 		const std::string PROPERTY(name);	// const std::string name;		std::string_view get_name() const;
+ * 		std::vector<int> PROPERTY(sizes);	// std::vector<int> sizes;		std::vector<int> const& get_sizes() const;
+ * 		uint8_t const* PROPERTY(data);		// uint8_t const* data;			uint8_t const* get_data() const;
+ * 		colour_t* PROPERTY(pixels);			// colour_t* pixels;			colour_t const* get_pixels() const;
+ * 		CultureGroup const& PROPERTY(group);// CultureGroup const& group;	CultureGroup const& get_group() const;
+ * 		Province& PROPERTY(province);		// Province& province;			Province const& get_province() const;
+ */
+#define PROPERTY(NAME) \
+	NAME; \
+\
+public: \
+	auto get_##NAME() const -> decltype(OpenVic::_get_property<decltype(NAME)>(NAME)) { \
+		return OpenVic::_get_property<decltype(NAME)>(NAME); \
+	} \
+\
+private:
+
+}