From afd10d62ca30f5d8b574e2a7ea1003f208b57281 Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Tue, 24 Dec 2013 20:56:34 -0800
Subject: [PATCH] feat(util/list): improve to_list function, it takes an
 optional tail

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
---
 src/util/list.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/util/list.h b/src/util/list.h
index b2ee3c7b62..74669a9081 100644
--- a/src/util/list.h
+++ b/src/util/list.h
@@ -169,8 +169,10 @@ template<typename T> unsigned length(list<T> const & l) {
 }
 
 /** \brief Return a list containing the elements in the subrange <tt>[begin, end)</tt>. */
-template<typename It> list<typename std::iterator_traits<It>::value_type> to_list(It const & begin, It const & end) {
-    list<typename std::iterator_traits<It>::value_type> r;
+template<typename It> list<typename std::iterator_traits<It>::value_type>
+to_list(It const & begin, It const & end,
+        list<typename std::iterator_traits<It>::value_type> const & ls = list<typename std::iterator_traits<It>::value_type>()) {
+    list<typename std::iterator_traits<It>::value_type> r = ls;
     auto it = end;
     while (it != begin) {
         --it;