kernel: IdString::in(const IdString &) as per @Tjoppen

diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index e12d9d0495d9a9b37aee70c2bcd50dc1061b2a09..7279835ea35803d61321c4e379a59471dcaf0d88 100644 (file)
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -369,7 +369,7 @@ namespace RTLIL
                        return result;
                }
 
-               bool in(IdString rhs) const { return *this == rhs; }
+               bool in(const IdString &rhs) const { return *this == rhs; }
                bool in(const char *rhs) const { return *this == rhs; }
                bool in(const std::string &rhs) const { return *this == rhs; }
                bool in(const pool<IdString> &rhs) const { return rhs.count(*this) != 0; }