From 5473e597bf5aa7a5dc7c831be332baeeddae086f Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Fri, 13 Sep 2019 11:13:57 -0700
Subject: [PATCH] Use template specialisation

---
 kernel/sigtools.h | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/kernel/sigtools.h b/kernel/sigtools.h
index 2f2d3f5c6..8c0434ceb 100644
--- a/kernel/sigtools.h
+++ b/kernel/sigtools.h
@@ -135,10 +135,10 @@ struct SigPool
 	}
 };
 
-template <typename T, class Compare = std::less<T>>
+template <typename T, class Compare=void>
 struct SigSet
 {
-	static_assert(!std::is_pointer<T>::value || !std::is_same<Compare, std::less<T>>::value, "Explicit `Compare' class required for SigSet with pointer-type values!");
+	static_assert(!std::is_same<Compare,void>::value, "Default value for `Compare' class not found for SigSet<T>. Please specify.");
 
 	struct bitDef_t : public std::pair<RTLIL::Wire*, int> {
 		bitDef_t() : std::pair<RTLIL::Wire*, int>(NULL, 0) { }
@@ -222,6 +222,13 @@ struct SigSet
 	}
 };
 
+template<typename T>
+class SigSet<T, typename std::enable_if<!std::is_pointer<T>::value>::type> : public SigSet<T, std::less<T>> {};
+template<typename T>
+using sort_by_name_id_guard = typename std::enable_if<std::is_same<T,RTLIL::Cell*>::value>::type;
+template<typename T>
+class SigSet<T, sort_by_name_id_guard<T>> : public SigSet<T, RTLIL::sort_by_name_id<typename std::remove_pointer<T>::type>> {};
+
 struct SigMap
 {
 	mfp<SigBit> database;
-- 
2.30.2