AK+Everywhere: Disallow returning a reference from a fallible expression

This will silently make a copy. Rather than masking this behavior, let's
explicitly disallow it.

1 files changed, 8 insertions, 6 deletions

diff --git a/Kernel/Net/Socket.h b/Kernel/Net/Socket.h
index 63f92aa270..b5bc494a77 100644
--- a/Kernel/Net/Socket.h
+++ b/Kernel/Net/Socket.h
@@ -184,12 +184,14 @@ private:
 };
 
 // This is a special variant of TRY() that also updates the socket's SO_ERROR field on error.
-#define SOCKET_TRY(expression)                           \
-    ({                                                   \
-        auto result = (expression);                      \
-        if (result.is_error())                           \
-            return set_so_error(result.release_error()); \
-        result.release_value();                          \
+#define SOCKET_TRY(expression)                                              \
+    ({                                                                      \
+        auto result = (expression);                                         \
+        if (result.is_error())                                              \
+            return set_so_error(result.release_error());                    \
+        static_assert(!IsLvalueReference<decltype(result.release_value())>, \
+            "Do not return a reference from a fallible expression");        \
+        result.release_value();                                             \
     })
 
 }