C++: Don't show unused mark for known RAII types

Change-Id: Id552539c6a2cf5d7558adf88bed61a11ab770516
Reviewed-by: Christian Kamm <christian.d.kamm@nokia.com>

src/plugins/cpptools/cpptoolsreuse.h

@@ -37,10 +37,18 @@
 
 QT_FORWARD_DECLARE_CLASS(QTextCursor)
 
+namespace CPlusPlus {
+class Symbol;
+class LookupContext;
+}
+
 namespace CppTools {
 
 void CPPTOOLS_EXPORT moveCursorToEndOfIdentifier(QTextCursor *tc);
 
+bool CPPTOOLS_EXPORT isOwnershipRAIIType(CPlusPlus::Symbol *symbol,
+                                         const CPlusPlus::LookupContext &context);
+
 } // CppTools
 
 #endif // CPPTOOLSREUSE_H