From 4dad08653ab1fcf16dd979b2156ad010eb31c0cc Mon Sep 17 00:00:00 2001
From: rbock <rbock@eudoxos.de>
Date: Tue, 11 Oct 2016 07:19:39 +0200
Subject: [PATCH] Maybe easier to grok for MSVC

---
 include/sqlpp11/union.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/sqlpp11/union.h b/include/sqlpp11/union.h
index 12fed78f..4e044eab 100644
--- a/include/sqlpp11/union.h
+++ b/include/sqlpp11/union.h
@@ -215,7 +215,8 @@ namespace sqlpp
 
         using lhs_result_row_t = get_result_row_t<derived_statement_t<Policies>>;
         using rhs_result_row_t = get_result_row_t<Rhs>;
-        static_assert(lhs_result_row_t::is_compatible(detail::type_vector<rhs_result_row_t>{}),
+        constexpr auto vec_rhs = detail::type_vector<rhs_result_row_t>{};
+        static_assert(lhs_result_row_t::is_compatible(vec_rhs),
                       "both arguments in a union have to have the same result columns (type and name)");
         static_assert(
             is_static_result_row_t<lhs_result_row_t>::value && is_static_result_row_t<rhs_result_row_t>::value,
@@ -236,7 +237,8 @@ namespace sqlpp
 
         using lhs_result_row_t = get_result_row_t<derived_statement_t<Policies>>;
         using rhs_result_row_t = get_result_row_t<Rhs>;
-        static_assert(lhs_result_row_t::is_compatible(detail::type_vector<rhs_result_row_t>{}),
+        constexpr auto vec_rhs = detail::type_vector<rhs_result_row_t>{};
+        static_assert(lhs_result_row_t::is_compatible(vec_rhs),
                       "both arguments in a union have to have the same result columns (type and name)");
         static_assert(
             is_static_result_row_t<lhs_result_row_t>::value && is_static_result_row_t<rhs_result_row_t>::value,