From 306969488b3fe4b761dbf84f7329d8d92d3cb4e2 Mon Sep 17 00:00:00 2001
From: Frank Park <fpark12@icloud.com>
Date: Mon, 20 Feb 2017 19:00:32 -0500
Subject: [PATCH] Fix variadic template pack expansion failure with VS2017 RC

---
 include/sqlpp11/having.h    | 2 +-
 include/sqlpp11/statement.h | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/sqlpp11/having.h b/include/sqlpp11/having.h
index a5fcfa6c..5f1dec6e 100644
--- a/include/sqlpp11/having.h
+++ b/include/sqlpp11/having.h
@@ -237,7 +237,7 @@ namespace sqlpp
       //	  template <typename... T>
       //	  using _check = logic::all_t<is_expression_t<T>::value...>;
       template <typename... T>
-      struct _check : logic::all_t<is_expression_t<T>::value...>
+      struct _check : logic::all_t<is_expression_t<T>::value...>...
       {
       };
 
diff --git a/include/sqlpp11/statement.h b/include/sqlpp11/statement.h
index 34af1dcc..20d2490f 100644
--- a/include/sqlpp11/statement.h
+++ b/include/sqlpp11/statement.h
@@ -121,8 +121,12 @@ namespace sqlpp
                _required_ctes::size::value == 0;
       }
 
+	  // work around for msvc bug:
+	  // error C3520 : 'Policies' : parameter pack must be expanded in this context
+	  using is_missing_policies_t_1 = logic::logic_helper<is_missing_t<Policies>::value...>;
+	  using is_missing_policies_t_2 = logic::logic_helper<(is_missing_t<Policies>::value && false)...>;
       using _value_type =
-          typename std::conditional<logic::none_t<is_missing_t<Policies>::value...>::value,
+          typename std::conditional<std::is_same<is_missing_policies_t_1, is_missing_policies_t_2>::value,
                                     value_type_of<_result_type_provider>,
                                     no_value_t  // if a required statement part is missing (e.g. columns in a select),
                                                 // then the statement cannot be used as a value