From e1da290f13f74e8244bc627a24c56ccdce31bf95 Mon Sep 17 00:00:00 2001
From: Simon Giraudot <simon.giraudot@geometryfactory.com>
Date: Mon, 18 Jun 2018 14:45:49 +0200
Subject: [PATCH] Fix conversion warning

---
 Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h b/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
index c1fe154ca0d..b28d643f531 100644
--- a/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
+++ b/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
@@ -123,7 +123,7 @@ namespace CGAL {
         /// decrement.
         SM_Index operator--(int) { SM_Index tmp(*this); --idx_; return tmp; }
 
-        SM_Index operator+=(std::ptrdiff_t n) { idx_ += n; return *this; }
+        SM_Index operator+=(std::ptrdiff_t n) { idx_ = size_type(std::ptrdiff_t(idx_) + n); return *this; }
       
     private:
         size_type idx_;