1 files changed, 84 insertions, 0 deletions
diff --git a/src/boost/libs/hana/test/map/at_key.ref.cpp b/src/boost/libs/hana/test/map/at_key.ref.cpp
new file mode 100644
index 000000000..c845bc134
--- /dev/null
+++ b/src/boost/libs/hana/test/map/at_key.ref.cpp
@@ -0,0 +1,84 @@
+// 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/at_key.hpp>
+#include <boost/hana/integral_constant.hpp>
+#include <boost/hana/map.hpp>
+#include <boost/hana/pair.hpp>
+
+#include <utility>
+namespace hana = boost::hana;
+
+
+template <typename T>
+T const& cref(T& t) { return t; }
+
+int main() {
+    // using at_key
+    {
+        auto xs = hana::make_map(
+            hana::make_pair(hana::int_c<0>, 0),
+            hana::make_pair(hana::int_c<1>, '1'),
+            hana::make_pair(hana::int_c<2>, 2.2)
+        );
+
+        // Make sure we return lvalue-references
+        BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<0>) == 0);
+        BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<1>) == '1');
+        BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<2>) == 2.2);
+
+        int& a = hana::at_key(xs, hana::int_c<0>);
+        char& b = hana::at_key(xs, hana::int_c<1>);
+        double& c = hana::at_key(xs, hana::int_c<2>);
+        a = 9;
+        b = '9';
+        c = 9.9;
+
+        // Make sure we return lvalue-references to const on a const map
+        int const& ca = hana::at_key(cref(xs), hana::int_c<0>);
+        char const& cb = hana::at_key(cref(xs), hana::int_c<1>);
+        double const& cc = hana::at_key(cref(xs), hana::int_c<2>);
+
+        BOOST_HANA_RUNTIME_CHECK(ca == 9);
+        BOOST_HANA_RUNTIME_CHECK(cb == '9');
+        BOOST_HANA_RUNTIME_CHECK(cc == 9.9);
+    }
+
+    // using operator[]
+    {
+        auto xs = hana::make_map(
+            hana::make_pair(hana::int_c<0>, 0),
+            hana::make_pair(hana::int_c<1>, '1'),
+            hana::make_pair(hana::int_c<2>, 2.2)
+        );
+
+        BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<0>] == 0);
+        BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<1>] == '1');
+        BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<2>] == 2.2);
+
+        xs[hana::int_c<0>] = 9;
+        xs[hana::int_c<1>] = '9';
+        xs[hana::int_c<2>] = 9.9;
+
+        BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<0>] == 9);
+        BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<1>] == '9');
+        BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<2>] == 9.9);
+    }
+
+    // Make sure we return a rvalue-reference from a temporary map
+    // (https://github.com/boostorg/hana/issues/90)
+    {
+        auto xs = hana::make_map(
+            hana::make_pair(hana::int_c<0>, 0),
+            hana::make_pair(hana::int_c<1>, '1'),
+            hana::make_pair(hana::int_c<2>, 2.2)
+        );
+
+        char&& c = hana::at_key(std::move(xs), hana::int_c<1>);
+        BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<1>) == '1');
+        c = '9';
+        BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<1>) == '9');
+    }
+}