refactor: continue refactor project from C++17 to 23

src/yycc/macro/os_detector.hpp

@@ -4,3 +4,25 @@
 #if (defined(YYCC_OS_WINDOWS) + defined(YYCC_OS_LINUX)) != 1
 #error "Current operating system is not supported!"
 #endif
+
+namespace yycc::macro::os {
+
+    /// @brief The operating system kind.
+    enum class OsKind {
+        Windows, ///< Microsoft Windows
+        Linux,   ///< GNU/Linux
+    };
+
+    /**
+     * @brief Fetch the operating system
+     * @return The kind of operating system.
+     */
+    inline constexpr OsKind get_os() {
+#if defined(YYCC_OS_WINDOWS)
+        return OsKind::Windows;
+#else
+        return OsKind::Linux;
+#endif
+    }
+
+} // namespace yycc::macro::os