add warning

yaito3014 · yaito3014 · commit 1411af031e39 · 2025-04-26T01:57:41.000+09:00
diff --git a/source.cpp b/source.cpp
@@ -1,5 +1,7 @@
 #include <iostream>
 
+#warning "WARNNING: This is a warning message"
+
 [[nodiscard]] int func() { return 42; }
 
 int main() {
