From fb79d23aaccf0ccf0e54f6f8aa8da3c28375242a Mon Sep 17 00:00:00 2001
From: joaquintides <joaquin@tid.es>
Date: Fri, 8 Nov 2024 19:08:50 +0100
Subject: [PATCH 1/4] improved performance of mp_is_set

---
 include/boost/mp11/set.hpp | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/boost/mp11/set.hpp b/include/boost/mp11/set.hpp
index 808636b7..3df0841e 100644
--- a/include/boost/mp11/set.hpp
+++ b/include/boost/mp11/set.hpp
@@ -1,7 +1,7 @@
 #ifndef BOOST_MP11_SET_HPP_INCLUDED
 #define BOOST_MP11_SET_HPP_INCLUDED
 
-// Copyright 2015, 2019 Peter Dimov.
+// Copyright 2015, 2019, 2024 Peter Dimov.
 //
 // Distributed under the Boost Software License, Version 1.0.
 //
@@ -94,19 +94,23 @@ template<class S, class... T> using mp_set_push_front = typename detail::mp_set_
 namespace detail
 {
 
-template<class S> struct mp_is_set_impl
+struct mp_is_set_helper_start
 {
-    using type = mp_false;
+    static constexpr bool value = true;
+    template<class T> static mp_false contains( T );
 };
 
-template<template<class...> class L, class... T> struct mp_is_set_impl<L<T...>>
+template<class Base, class T>
+struct mp_is_set_helper: Base
 {
-    using type = mp_to_bool<std::is_same<mp_list<T...>, mp_set_push_back<mp_list<>, T...> > >;
+    static constexpr bool value = Base::value && !decltype( Base::contains( mp_identity<T>{} ) )::value;
+    using Base::contains;
+    static mp_true contains( mp_identity<T> );
 };
 
 } // namespace detail
 
-template<class S> using mp_is_set = typename detail::mp_is_set_impl<S>::type;
+template<class S> using mp_is_set = mp_bool<mp_fold<S, detail::mp_is_set_helper_start, detail::mp_is_set_helper>::value>;
 
 // mp_set_union<L...>
 namespace detail

From 13a81c86eef5433ec08897548d088c8e0d19993e Mon Sep 17 00:00:00 2001
From: joaquintides <joaquin@tid.es>
Date: Fri, 8 Nov 2024 19:21:27 +0100
Subject: [PATCH 2/4] added missing #include

---
 include/boost/mp11/set.hpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/boost/mp11/set.hpp b/include/boost/mp11/set.hpp
index 3df0841e..af18af85 100644
--- a/include/boost/mp11/set.hpp
+++ b/include/boost/mp11/set.hpp
@@ -13,6 +13,7 @@
 #include <boost/mp11/detail/mp_list.hpp>
 #include <boost/mp11/detail/mp_append.hpp>
 #include <boost/mp11/detail/mp_copy_if.hpp>
+#include <boost/mp11/detail/mp_fold.hpp>
 #include <boost/mp11/detail/mp_remove_if.hpp>
 #include <boost/mp11/detail/mp_is_list.hpp>
 #include <type_traits>

From c2bc9788caba1cf3c3c81c977fc0a78189f8c1f0 Mon Sep 17 00:00:00 2001
From: joaquintides <joaquin@tid.es>
Date: Fri, 8 Nov 2024 19:50:48 +0100
Subject: [PATCH 3/4] made mp_is_set<S> robust when S is not a list

---
 include/boost/mp11/set.hpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/boost/mp11/set.hpp b/include/boost/mp11/set.hpp
index af18af85..f8c2f26a 100644
--- a/include/boost/mp11/set.hpp
+++ b/include/boost/mp11/set.hpp
@@ -109,9 +109,19 @@ struct mp_is_set_helper: Base
     static mp_true contains( mp_identity<T> );
 };
 
+template<class S> struct mp_is_set_impl
+{
+    using type = mp_false;
+};
+
+template<template<class...> class L, class... T> struct mp_is_set_impl<L<T...>>
+{
+    using type = mp_bool<mp_fold<mp_list<T...>, detail::mp_is_set_helper_start, detail::mp_is_set_helper>::value>;
+};
+
 } // namespace detail
 
-template<class S> using mp_is_set = mp_bool<mp_fold<S, detail::mp_is_set_helper_start, detail::mp_is_set_helper>::value>;
+template<class S> using mp_is_set = typename detail::mp_is_set_impl<S>::type;
 
 // mp_set_union<L...>
 namespace detail

From 28929d97947ac401fc17a521cbd3ef27f6dd41d4 Mon Sep 17 00:00:00 2001
From: joaquintides <joaquin@tid.es>
Date: Fri, 8 Nov 2024 22:07:10 +0100
Subject: [PATCH 4/4] kept old impl for msvc 12.0

---
 include/boost/mp11/set.hpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/boost/mp11/set.hpp b/include/boost/mp11/set.hpp
index f8c2f26a..d65e4aeb 100644
--- a/include/boost/mp11/set.hpp
+++ b/include/boost/mp11/set.hpp
@@ -10,6 +10,7 @@
 
 #include <boost/mp11/utility.hpp>
 #include <boost/mp11/function.hpp>
+#include <boost/mp11/detail/config.hpp>
 #include <boost/mp11/detail/mp_list.hpp>
 #include <boost/mp11/detail/mp_append.hpp>
 #include <boost/mp11/detail/mp_copy_if.hpp>
@@ -95,6 +96,8 @@ template<class S, class... T> using mp_set_push_front = typename detail::mp_set_
 namespace detail
 {
 
+#if !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1900 )
+
 struct mp_is_set_helper_start
 {
     static constexpr bool value = true;
@@ -119,6 +122,20 @@ template<template<class...> class L, class... T> struct mp_is_set_impl<L<T...>>
     using type = mp_bool<mp_fold<mp_list<T...>, detail::mp_is_set_helper_start, detail::mp_is_set_helper>::value>;
 };
 
+#else
+
+template<class S> struct mp_is_set_impl
+{
+    using type = mp_false;
+};
+
+template<template<class...> class L, class... T> struct mp_is_set_impl<L<T...>>
+{
+    using type = mp_to_bool<std::is_same<mp_list<T...>, mp_set_push_back<mp_list<>, T...> > >;
+};
+
+#endif // !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1900 )
+
 } // namespace detail
 
 template<class S> using mp_is_set = typename detail::mp_is_set_impl<S>::type;