From f0acc9326ee54534eb31ec1636608dd01f232790 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Sun, 24 Mar 2024 19:16:09 +0200
Subject: [PATCH] Work around MSVC failures in variant_derived_construct2. Refs
 #43.

---
 include/boost/variant2/variant.hpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/boost/variant2/variant.hpp b/include/boost/variant2/variant.hpp
index aec8966..1668436 100644
--- a/include/boost/variant2/variant.hpp
+++ b/include/boost/variant2/variant.hpp
@@ -1634,7 +1634,17 @@ public:
     template<class U,
         class Ud = typename std::decay<U>::type,
         class E1 = typename std::enable_if< !std::is_same<Ud, variant>::value && !std::is_base_of<variant, Ud>::value && !detail::is_in_place_index<Ud>::value && !detail::is_in_place_type<Ud>::value >::type,
+
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1940)
+
+        class V = mp11::mp_apply_q< mp11::mp_bind_front<detail::resolve_overload_type, U&&>, variant >,
+
+#else
+
         class V = detail::resolve_overload_type<U&&, T...>,
+
+#endif
+
         class E2 = typename std::enable_if<std::is_constructible<V, U&&>::value>::type
         >
     constexpr variant( U&& u )