From 2c8ce53efb8524f7d546f4aecaccf17f62cc6db8 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Thu, 19 Mar 2020 16:11:39 +0200
Subject: [PATCH] Apply a workaround for msvc-12.0

---
 include/boost/mp11/algorithm.hpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/boost/mp11/algorithm.hpp b/include/boost/mp11/algorithm.hpp
index cc749a9..4ee111b 100644
--- a/include/boost/mp11/algorithm.hpp
+++ b/include/boost/mp11/algorithm.hpp
@@ -1140,11 +1140,23 @@ template<class L> using mp_power_set = typename detail::mp_power_set_impl<L>::ty
 namespace detail
 {
 
+#if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, <= 1800 )
+
+template<template<class...> class L, class... T> struct mp_power_set_impl< L<T...> >
+{
+    static_assert( sizeof...(T) == 0, "T... must be empty" );
+    using type = L< L<> >;
+};
+
+#else
+
 template<template<class...> class L> struct mp_power_set_impl< L<> >
 {
     using type = L< L<> >;
 };
 
+#endif
+
 template<template<class...> class L, class T1, class... T> struct mp_power_set_impl< L<T1, T...> >
 {
     using S1 = mp_power_set< L<T...> >;