From 7a4f56e74be85ad2042201704ec7927691efbb6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCnter=20Obiltschnig?= <guenter.obiltschnig@appinf.com>
Date: Sat, 22 Jun 2019 14:06:47 +0200
Subject: [PATCH] fixed GH #2382: Tuple assignment very slow

---
 Foundation/include/Poco/TypeList.h | 66 +++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 24 deletions(-)

diff --git a/Foundation/include/Poco/TypeList.h b/Foundation/include/Poco/TypeList.h
index 5620fa274..352696f8e 100644
--- a/Foundation/include/Poco/TypeList.h
+++ b/Foundation/include/Poco/TypeList.h
@@ -32,7 +32,7 @@ namespace Poco {
 template <class Head, class Tail> 
 struct TypeList;
 
-	
+
 struct NullTypeList
 {
 	enum
@@ -86,8 +86,8 @@ struct TypeList
 	{
 		if (this != &tl)
 		{
-			TypeList tmp(tl);
-			swap(tmp);
+			head = tl.head;
+			tail = tl.tail;
 		}
 		return *this;
 	}
@@ -110,40 +110,54 @@ struct TypeList
 			return tail < tl.tail;
 		return false;
 	}
-
-	void swap(TypeList& tl)
-	{
-		std::swap(head, tl.head);
-		std::swap(tail, tl.tail);
-	}
 	
 	HeadType head;
 	TailType tail;
 };
 
 
-template <typename T0  = NullTypeList, 
-	typename T1  = NullTypeList, 
+template <typename T0  = NullTypeList,
+	typename T1  = NullTypeList,
 	typename T2  = NullTypeList,
-	typename T3  = NullTypeList, 
-	typename T4  = NullTypeList, 
+	typename T3  = NullTypeList,
+	typename T4  = NullTypeList,
 	typename T5  = NullTypeList,
-	typename T6  = NullTypeList, 
-	typename T7  = NullTypeList, 
+	typename T6  = NullTypeList,
+	typename T7  = NullTypeList,
 	typename T8  = NullTypeList,
-	typename T9  = NullTypeList, 
-	typename T10 = NullTypeList, 
+	typename T9  = NullTypeList,
+	typename T10 = NullTypeList,
 	typename T11 = NullTypeList,
-	typename T12 = NullTypeList, 
-	typename T13 = NullTypeList, 
+	typename T12 = NullTypeList,
+	typename T13 = NullTypeList,
 	typename T14 = NullTypeList,
-	typename T15 = NullTypeList, 
-	typename T16 = NullTypeList, 
+	typename T15 = NullTypeList,
+	typename T16 = NullTypeList,
 	typename T17 = NullTypeList,
 	typename T18 = NullTypeList,
-	typename T19 = NullTypeList> 
+	typename T19 = NullTypeList,
+	typename T20 = NullTypeList,
+	typename T21 = NullTypeList,
+	typename T22 = NullTypeList,
+	typename T23 = NullTypeList,
+	typename T24 = NullTypeList,
+	typename T25 = NullTypeList,
+	typename T26 = NullTypeList,
+	typename T27 = NullTypeList,
+	typename T28 = NullTypeList,
+	typename T29 = NullTypeList,
+	typename T30 = NullTypeList,
+	typename T31 = NullTypeList,
+	typename T32 = NullTypeList,
+	typename T33 = NullTypeList,
+	typename T34 = NullTypeList,
+	typename T35 = NullTypeList,
+	typename T36 = NullTypeList,
+	typename T37 = NullTypeList,
+	typename T38 = NullTypeList,
+	typename T39 = NullTypeList>
 struct TypeListType
-	/// TypeListType takes 1 - 20 typename arguments.
+	/// TypeListType takes 1 - 40 typename arguments.
 	/// Usage:
 	///
 	/// TypeListType<T0, T1, ... , Tn>::HeadType typeList;
@@ -151,7 +165,11 @@ struct TypeListType
 	/// typeList is a TypeList of T0, T1, ... , Tn
 {
 private:
-	typedef typename TypeListType<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,T17,T18,T19>::HeadType TailType;
+	typedef typename
+		TypeListType<T1,T2, T3, T4, T5, T6, T7, T8, T9, T10,
+					T11,T12,T13,T14,T15,T16,T17,T18,T19,T20,
+					T21,T22,T23,T24,T25,T26,T27,T28,T29,T30,
+					T31,T32,T33,T34,T35,T36,T37,T38,T39>::HeadType TailType;
 
 public:
 	typedef TypeList<T0, TailType> HeadType;