From 79f45c32013b0816c5e499a2db9a449001cd0227 Mon Sep 17 00:00:00 2001
From: Ryan Curtin <ryan@ratml.org>
Date: Wed, 14 Dec 2016 13:22:01 -0500
Subject: [PATCH] Fix Windows build: it's not necessary to define enable_if_t
 for all MSVC versions.

---
 src/mlpack/prereqs.hpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mlpack/prereqs.hpp b/src/mlpack/prereqs.hpp
index 7a3fea6e0ad..eb172ab15b5 100644
--- a/src/mlpack/prereqs.hpp
+++ b/src/mlpack/prereqs.hpp
@@ -52,6 +52,7 @@
 
 // Backport this functionality from C++14, if it doesn't exist.
 #if __cplusplus <= 201103L
+#if !defined(_MSC_VER) || _MSC_VER <= 1800
 namespace std {
 
 template<bool B, class T = void>
@@ -59,6 +60,7 @@ using enable_if_t = typename enable_if<B, T>::type;
 
 }
 #endif
+#endif
 
 // We'll need the necessary boost::serialization features, as well as what we
 // use with mlpack.  In Boost 1.59 and newer, the BOOST_PFTO code is no longer