missing std::

Former-commit-id: d8ec89e95699124efc6210a726dd5994f8fc65b2

include/igl/round.cpp

@@ -1,9 +1,9 @@
 // This file is part of libigl, a simple c++ geometry processing library.
-// 
+//
 // Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
-// 
-// This Source Code Form is subject to the terms of the Mozilla Public License 
-// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
 // obtain one at http://mozilla.org/MPL/2.0/.
 #include "round.h"
 #include <cmath>
@@ -13,7 +13,7 @@
 template <typename DerivedX >
 IGL_INLINE DerivedX igl::round(const DerivedX r)
 {
-  return (r > 0.0) ? floor(r + 0.5) : ceil(r - 0.5);
+  return (r > 0.0) ? std::floor(r + 0.5) : std::ceil(r - 0.5);
 }
 
 template < typename DerivedX, typename DerivedY>