From e9f104987164afca55d568d20c0f056a42fe57a6 Mon Sep 17 00:00:00 2001
From: Matt Borland <matt@mattborland.com>
Date: Wed, 10 Jan 2024 12:36:41 +0100
Subject: [PATCH] Fix reference wrapper for MSVC

---
 include/boost/numeric/odeint/config.hpp       |  2 +-
 .../numeric/odeint/util/unwrap_reference.hpp  | 25 -------------------
 2 files changed, 1 insertion(+), 26 deletions(-)

diff --git a/include/boost/numeric/odeint/config.hpp b/include/boost/numeric/odeint/config.hpp
index f1915825..964bb1bd 100644
--- a/include/boost/numeric/odeint/config.hpp
+++ b/include/boost/numeric/odeint/config.hpp
@@ -43,7 +43,7 @@
 
 #include <boost/config.hpp>
 
-#if __cplusplus >= 201103L
+#if __cplusplus >= 201103L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201103L)
 #define BOOST_NUMERIC_ODEINT_CXX11 1
 #endif
 
diff --git a/include/boost/numeric/odeint/util/unwrap_reference.hpp b/include/boost/numeric/odeint/util/unwrap_reference.hpp
index e1608783..bbe087b2 100644
--- a/include/boost/numeric/odeint/util/unwrap_reference.hpp
+++ b/include/boost/numeric/odeint/util/unwrap_reference.hpp
@@ -20,28 +20,16 @@
 
 
 #include <boost/numeric/odeint/config.hpp>
-
-
-#if BOOST_NUMERIC_ODEINT_CXX11
 #include <functional>
-#else
-#include <boost/ref.hpp>
-#endif
 
 namespace boost {
 
-#if BOOST_NUMERIC_ODEINT_CXX11
 template<typename T> class reference_wrapper;
-
 template<typename T> struct unwrap_reference;
-#endif
 
 namespace numeric {
 namespace odeint {
 
-
-#if BOOST_NUMERIC_ODEINT_CXX11
-
 template<typename T>
 struct unwrap_reference
 {
@@ -60,24 +48,11 @@ struct unwrap_reference< boost::reference_wrapper<T> >
     typedef typename boost::unwrap_reference<T>::type type;
 };
 
-#else
-
-using ::boost::unwrap_reference;
-
-#endif
-
 namespace detail
 {
 
-#if BOOST_NUMERIC_ODEINT_CXX11
-
 using ::std::ref;
 
-#else
-
-using ::boost::ref;
-
-#endif
 }
 
 }