Fix issue 11267.

Compiler yields compile error within a function witch used in unevaluate
context of constexpr function because of CWG 1581 [2].

1. https://llvm.org/bugs/show_bug.cgi?id=23135
2. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1581

test/Jamfile

@@ -78,6 +78,7 @@ project
     [ run sequence/list_make.cpp :  :  :  : ]
     [ run sequence/list_misc.cpp :  :  :  : ]
     [ run sequence/list_mutate.cpp :  :  :  : ]
+    [ run sequence/list_nest.cpp :  :  :  : ]
     [ run sequence/list_tie.cpp :  :  :  : ]
     [ run sequence/list_value_at.cpp :  :  :  : ]
     [ run sequence/deque_comparison.cpp :  :  :  : ]
@@ -89,6 +90,7 @@ project
     [ run sequence/deque_misc.cpp :  :  :  : ]
     [ run sequence/deque_move.cpp :  :  :  : ]
     [ run sequence/deque_mutate.cpp :  :  :  : ]
+    [ run sequence/deque_nest.cpp :  :  :  : ]
     [ run sequence/deque_tie.cpp :  :  :  : ]
     [ run sequence/deque_value_at.cpp :  :  :  : ]
     [ run sequence/front_extended_deque.cpp :  :  :  : ]
@@ -131,6 +133,7 @@ project
     [ run sequence/vector_move.cpp :  :  :  : ]
     [ run sequence/vector_mutate.cpp :  :  :  : ]
     [ run sequence/vector_n.cpp :  :  :  : ]
+    [ run sequence/vector_nest.cpp :  :  :  : ]
     [ run sequence/vector_hash.cpp :  :  :  : ]
     [ run sequence/vector_tie.cpp :  :  :  : ]
     [ run sequence/vector_value_at.cpp :  :  :  : ]
@@ -184,6 +187,7 @@ project
     [ compile support/pair_map.cpp : : : : ]
     [ compile support/pair_set.cpp : : : : ]
     [ compile support/pair_vector.cpp : : : : ]
+    [ compile support/pair_nest.cpp : : : : ]
 
 #   [ compile-fail xxx.cpp :  :  :  :  ]
 

test/sequence/deque_nest.cpp

@@ -0,0 +1,19 @@
+/*=============================================================================
+    Copyright (C) 2015 Kohei Takahshi
+
+    Distributed under the Boost Software License, Version 1.0. (See accompanying
+    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+#include <boost/fusion/container/deque/deque.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#define FUSION_SEQUENCE deque
+#include "nest.hpp"
+
+int
+main()
+{
+    test();
+    return boost::report_errors();
+}
+

test/sequence/list_nest.cpp

@@ -0,0 +1,19 @@
+/*=============================================================================
+    Copyright (C) 2015 Kohei Takahshi
+
+    Distributed under the Boost Software License, Version 1.0. (See accompanying 
+    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+#include <boost/fusion/container/list/list.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#define FUSION_SEQUENCE list
+#include "nest.hpp"
+
+int
+main()
+{
+    test();
+    return boost::report_errors();
+}
+

test/sequence/nest.hpp

@@ -0,0 +1,58 @@
+/*=============================================================================
+    Copyright (C) 2015 Kohei Takahshi
+
+    Distributed under the Boost Software License, Version 1.0. (See accompanying
+    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+
+#include <utility>
+#include <boost/config.hpp>
+
+template <typename C>
+void test_copy()
+{
+    C src;
+    C dst = src;
+    (void)dst;
+}
+
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+template <typename C>
+void test_move()
+{
+    C src;
+    C dst = std::move(src);
+    (void)dst;
+}
+#endif
+
+template <typename C>
+void test_all()
+{
+    test_copy<C>();
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+    test_move<C>();
+#endif
+}
+
+void
+test()
+{
+    using namespace boost::fusion;
+
+    test_all<FUSION_SEQUENCE<FUSION_SEQUENCE<> > >();
+    test_all<FUSION_SEQUENCE<FUSION_SEQUENCE<>, int> >();
+    test_all<FUSION_SEQUENCE<int, FUSION_SEQUENCE<> > >();
+    test_all<FUSION_SEQUENCE<int, FUSION_SEQUENCE<>, float> >();
+
+    test_all<FUSION_SEQUENCE<FUSION_SEQUENCE<int> > >();
+    test_all<FUSION_SEQUENCE<FUSION_SEQUENCE<int>, int> >();
+    test_all<FUSION_SEQUENCE<int, FUSION_SEQUENCE<int> > >();
+    test_all<FUSION_SEQUENCE<int, FUSION_SEQUENCE<int>, float> >();
+
+    test_all<FUSION_SEQUENCE<FUSION_SEQUENCE<int, float> > >();
+    test_all<FUSION_SEQUENCE<FUSION_SEQUENCE<int, float>, int> >();
+    test_all<FUSION_SEQUENCE<int, FUSION_SEQUENCE<int, float> > >();
+    test_all<FUSION_SEQUENCE<int, FUSION_SEQUENCE<int, float>, float> >();
+}
+

test/sequence/vector_nest.cpp

@@ -0,0 +1,19 @@
+/*=============================================================================
+    Copyright (C) 2015 Kohei Takahshi
+
+    Distributed under the Boost Software License, Version 1.0. (See accompanying 
+    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+#include <boost/fusion/container/vector/vector.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#define FUSION_SEQUENCE vector
+#include "nest.hpp"
+
+int
+main()
+{
+    test();
+    return boost::report_errors();
+}
+

test/support/pair_nest.cpp

@@ -0,0 +1,24 @@
+/*=============================================================================
+    Copyright (c) 2015 Kohei Takahashi
+
+    Distributed under the Boost Software License, Version 1.0. (See accompanying
+    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+#include <boost/core/ignore_unused.hpp>
+#include <boost/fusion/support/pair.hpp>
+
+using namespace boost::fusion;
+
+template <typename C>
+void copy()
+{
+    pair<int, C> src;
+    pair<int, C> dest = src;
+    boost::ignore_unused(dest);
+}
+
+int main()
+{
+    copy<pair<void, float> >();
+}
+