Add mp_valid, mp_defer, mp_defer_if_valid.

2015-07-16 00:40:40 +03:00
parent a5dd767f93
commit 61b897e857
5 changed files with 154 additions and 0 deletions
@@ -0,0 +1,72 @@
+
+//  Copyright 2015 Peter Dimov.
+//
+// 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/mp11/utility.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+template<class T> struct Xi
+{
+};
+
+template<> struct Xi<void>
+{
+    using type = void;
+};
+
+template<class T> using X = typename Xi<T>::type;
+
+template<class T> using add_pointer = T*;
+template<class T> using add_reference = T&;
+template<class T> using add_extents = T[];
+
+int main()
+{
+    using boost::mp_valid;
+    using boost::mp_identity;
+
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_identity>));
+    BOOST_TEST_TRAIT_TRUE((mp_valid<mp_identity, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_identity, void, void>));
+
+    BOOST_TEST_TRAIT_FALSE((mp_valid<X>));
+    BOOST_TEST_TRAIT_TRUE((mp_valid<X, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<X, int>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<X, void, void>));
+
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_pointer>));
+    BOOST_TEST_TRAIT_TRUE((mp_valid<add_pointer, void>));
+    BOOST_TEST_TRAIT_TRUE((mp_valid<add_pointer, int>));
+#if !defined( BOOST_MSVC ) || !BOOST_WORKAROUND( BOOST_MSVC, <= 1800 )
+    // msvc-12.0 can form pointer to reference
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_pointer, int&>));
+#endif
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_pointer, void, void>));
+
+#if !defined( BOOST_GCC ) || !BOOST_WORKAROUND( BOOST_GCC, <= 40902 )
+    // g++ 4.9.2 doesn't like add_reference for some reason or other
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_reference>));
+#if !defined( BOOST_MSVC ) || !BOOST_WORKAROUND( BOOST_MSVC, <= 1800 )
+    // msvc-12.0 gives an internal error here
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_reference, void>));
+#endif
+    BOOST_TEST_TRAIT_TRUE((mp_valid<add_reference, int>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_reference, int, int>));
+#endif
+
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_extents>));
+    BOOST_TEST_TRAIT_TRUE((mp_valid<add_extents, int>));
+#if !defined( BOOST_MSVC ) || !BOOST_WORKAROUND( BOOST_MSVC, <= 1800 )
+    // msvc-12.0 can form arrays to void or int&
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_extents, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_extents, int&>));
+#endif
+    BOOST_TEST_TRAIT_FALSE((mp_valid<add_extents, int, int>));
+
+    return boost::report_errors();
+}