From 648ce1903811cdbf36df6ac5d2cab2727ca4d578 Mon Sep 17 00:00:00 2001
From: bolero-MURAKAMI <bolero.murakami@gmail.com>
Date: Wed, 15 Jul 2015 19:42:31 +0900
Subject: [PATCH] fix advance (N4442)

---
 sprout/iterator/advance.hpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sprout/iterator/advance.hpp b/sprout/iterator/advance.hpp
index 614d7b95..f2557921 100644
--- a/sprout/iterator/advance.hpp
+++ b/sprout/iterator/advance.hpp
@@ -45,9 +45,9 @@ namespace sprout {
 	//
 	// advance
 	//
-	template<typename Iterator, typename Distance>
+	template<typename Iterator, typename Distance = typename std::iterator_traits<Iterator>::difference_type>
 	inline SPROUT_CXX14_CONSTEXPR void
-	advance(Iterator& it, Distance n) {
+	advance(Iterator& it, Distance n = 1) {
 		typedef typename std::iterator_traits<Iterator>::iterator_category* category;
 		sprout::detail::advance_impl(it, n, category());
 	}