1 files changed, 72 insertions, 0 deletions
diff --git a/src/boost/libs/hana/test/type/metafunction.cpp b/src/boost/libs/hana/test/type/metafunction.cpp
new file mode 100644
index 000000000..aa52c1f38
--- /dev/null
+++ b/src/boost/libs/hana/test/type/metafunction.cpp
@@ -0,0 +1,72 @@
+// Copyright Louis Dionne 2013-2017
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+
+#include <boost/hana/assert.hpp>
+#include <boost/hana/concept/metafunction.hpp>
+#include <boost/hana/equal.hpp>
+#include <boost/hana/not.hpp>
+#include <boost/hana/type.hpp>
+
+#include <type_traits>
+namespace hana = boost::hana;
+
+
+struct x1; struct x2; struct x3;
+struct y1 { }; struct y2 { }; struct y3 { };
+template <typename ...> struct f { struct type; };
+
+template <typename F, typename ...T>
+constexpr auto valid_call(F f, T ...t) -> decltype(((void)f(t...)), true)
+{ return true; }
+constexpr auto valid_call(...)
+{ return false; }
+
+BOOST_HANA_CONSTANT_CHECK(hana::equal(
+    hana::metafunction<f>(),
+    hana::type_c<f<>::type>
+));
+
+BOOST_HANA_CONSTANT_CHECK(hana::equal(
+    hana::metafunction<f>(hana::type_c<x1>),
+    hana::type_c<f<x1>::type>
+));
+
+BOOST_HANA_CONSTANT_CHECK(hana::equal(
+    hana::metafunction<f>(hana::type_c<x1>, hana::type_c<x2>),
+    hana::type_c<f<x1, x2>::type>
+));
+
+BOOST_HANA_CONSTANT_CHECK(hana::equal(
+    hana::metafunction<f>(hana::type_c<x1>, hana::type_c<x2>, hana::type_c<x3>),
+    hana::type_c<f<x1, x2, x3>::type>
+));
+
+using F = decltype(hana::metafunction<f>);
+static_assert(std::is_same<F::apply<>, f<>>::value, "");
+static_assert(std::is_same<F::apply<x1>, f<x1>>::value, "");
+static_assert(std::is_same<F::apply<x1, x2>, f<x1, x2>>::value, "");
+static_assert(std::is_same<F::apply<x1, x2, x3>, f<x1, x2, x3>>::value, "");
+
+// Make sure we're SFINAE-friendly
+template <typename ...T> struct no_type { };
+static_assert(!valid_call(hana::metafunction<no_type>), "");
+static_assert(!valid_call(hana::metafunction<no_type>, hana::type_c<x1>), "");
+
+// Make sure we model the Metafunction concept
+static_assert(hana::Metafunction<decltype(hana::metafunction<f>)>::value, "");
+static_assert(hana::Metafunction<decltype(hana::metafunction<f>)&>::value, "");
+
+// Make sure metafunction is SFINAE-friendly
+template <typename T> struct not_a_metafunction { };
+BOOST_HANA_CONSTANT_CHECK(hana::not_(
+    hana::is_valid(hana::metafunction<not_a_metafunction>)(hana::type_c<void>)
+));
+
+
+// Make sure we don't read from a non-constexpr variable
+int main() {
+    auto t = hana::type_c<x1>;
+    constexpr auto r = hana::metafunction<f>(t);
+    (void)r;
+}