1 files changed, 71 insertions, 0 deletions
diff --git a/src/boost/libs/hana/test/optional/sfinae.cpp b/src/boost/libs/hana/test/optional/sfinae.cpp
new file mode 100644
index 000000000..e821c248c
--- /dev/null
+++ b/src/boost/libs/hana/test/optional/sfinae.cpp
@@ -0,0 +1,71 @@
+// 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/chain.hpp>
+#include <boost/hana/equal.hpp>
+#include <boost/hana/optional.hpp>
+
+#include <laws/base.hpp>
+#include <support/tracked.hpp>
+namespace hana = boost::hana;
+using hana::test::ct_eq;
+
+
+struct undefined { };
+
+int main() {
+    hana::test::_injection<0> f{};
+
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        hana::sfinae(f)(),
+        hana::just(f())
+    ));
+
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        hana::sfinae(f)(ct_eq<0>{}),
+        hana::just(f(ct_eq<0>{}))
+    ));
+
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        hana::sfinae(f)(ct_eq<0>{}, ct_eq<1>{}),
+        hana::just(f(ct_eq<0>{}, ct_eq<1>{}))
+    ));
+
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        hana::sfinae(undefined{})(),
+        hana::nothing
+    ));
+
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        hana::sfinae(undefined{})(ct_eq<0>{}),
+        hana::nothing
+    ));
+
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        hana::sfinae(undefined{})(ct_eq<0>{}, ct_eq<1>{}),
+        hana::nothing
+    ));
+
+    auto incr = hana::sfinae([](auto x) -> decltype(x + 1) {
+        return x + 1;
+    });
+
+    BOOST_HANA_RUNTIME_CHECK(hana::equal(
+        incr(1),
+        hana::just(2)
+    ));
+    BOOST_HANA_CONSTANT_CHECK(hana::equal(
+        incr(undefined{}),
+        hana::nothing
+    ));
+    BOOST_HANA_RUNTIME_CHECK(hana::equal(
+        hana::chain(hana::just(1), incr),
+        hana::just(2)
+    ));
+
+    // using `sfinae` with a non-pod argument used to fail
+    hana::sfinae(undefined{})(Tracked{1});
+    hana::sfinae([t = Tracked{1}](auto) { return 1; })(Tracked{1});
+}