avoid lambda to simplify source code

main.cpp

@@ -88,7 +88,10 @@ static void PrintDecodedFrame(const DecodedFrameValue &decoded) {
 
         std::cout << "  " << signal.definition->name
                   << " raw=";
-        std::visit([](auto rawValue) { std::cout << rawValue; }, signal.rawValue);
+        if (const auto *signedValue = std::get_if<std::int64_t>(&signal.rawValue))
+            std::cout << *signedValue;
+        else
+            std::cout << std::get<std::uint64_t>(signal.rawValue);
         std::cout << " physical=" << signal.physicalValue
                   << " " << signal.definition->unit
                   << "\n";