Add mp_find, mp_find_if.

test/mp_find.cpp

@@ -0,0 +1,54 @@
+
+//  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/algorithm.hpp>
+#include <boost/mp11/list.hpp>
+#include <boost/mp11/integral.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+#include <type_traits>
+#include <tuple>
+#include <utility>
+
+struct X1 {};
+struct X2 {};
+struct X3 {};
+
+int main()
+{
+    using boost::mp_list;
+    using boost::mp_find;
+
+    {
+        using L1 = mp_list<>;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L1, void>, L1>));
+
+        using L2 = mp_list<X1, X2, X2, X3, X3, X3>;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L2, void>, mp_list<>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L2, X1>, L2>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L2, X2>, mp_list<X2, X2, X3, X3, X3>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L2, X3>, mp_list<X3, X3, X3>>));
+    }
+
+    {
+        using L3 = std::tuple<>;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L3, void>, L3>));
+
+        using L4 = std::tuple<X1, X2, X2, X3, X3, X3>;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L4, void>, std::tuple<>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L4, X1>, L4>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L4, X2>, std::tuple<X2, X2, X3, X3, X3>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_find<L4, X3>, std::tuple<X3, X3, X3>>));
+    }
+
+    return boost::report_errors();
+}