kernel: IdString:in() to use perfect forwarding

diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index 7c1523f0bbef235bc4703731b72ff7c19f51316c..1283db1344340dc0bac119ed59c0d1209fbd61e5 100644 (file)
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -359,8 +359,8 @@ namespace RTLIL
                // of cell types). the following functions helps with that.
 
                template<typename T, typename... Args>
-               bool in(T first, Args... rest) const {
-                       return in(first) || in(rest...);
+               bool in(T first, Args&&... rest) const {
+                       return in(first) || in(std::forward<Args>(rest)...);
                }
 
                bool in(IdString rhs) const { return *this == rhs; }