Added a test for set that uses void* as a key.

test/voidptr_key_test.cpp

@@ -0,0 +1,94 @@
+/////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Andrey Semashev 2018.
+//
+// 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)
+//
+// See http://www.boost.org/libs/intrusive for documentation.
+//
+/////////////////////////////////////////////////////////////////////////////
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/set.hpp>
+#include <boost/intrusive/set_hook.hpp>
+#include <boost/config.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <functional> // std::less
+
+// The test verifies that the set implementation does not use void* as auxiliary arguments for SFINAE
+// in internal functions, which would make overload resolution ambiguous if user's key type is also void*.
+
+typedef boost::intrusive::set_base_hook<
+    boost::intrusive::link_mode< boost::intrusive::safe_link >,
+    boost::intrusive::tag< struct for_set_element_lookup_by_key >,
+    boost::intrusive::optimize_size< true >
+> set_element_hook_t;
+
+struct set_element :
+    public set_element_hook_t
+{
+    struct order_by_key
+    {
+        typedef bool result_type;
+
+        result_type operator() (set_element const& left, set_element const& right) const
+        {
+            return std::less< void* >()(left.m_key, right.m_key);
+        }
+        result_type operator() (void* left, set_element const& right) const
+        {
+            return std::less< void* >()(left, right.m_key);
+        }
+        result_type operator() (set_element const& left, void* right) const
+        {
+            return std::less< void* >()(left.m_key, right);
+        }
+    };
+
+    void* m_key;
+
+    explicit set_element(void* key) : m_key(key) {}
+
+    BOOST_DELETED_FUNCTION(set_element(set_element const&))
+    BOOST_DELETED_FUNCTION(set_element& operator=(set_element const&))
+};
+
+typedef boost::intrusive::set<
+    set_element,
+    boost::intrusive::base_hook< set_element_hook_t >,
+    boost::intrusive::compare< set_element::order_by_key >,
+    boost::intrusive::constant_time_size< true >
+> set_t;
+
+void test_set()
+{
+    int v1 = 0, v2 = 1, v3 = 2;
+    set_element e1(&v1), e2(&v2), e3(&v3);
+
+    set_t s;
+    s.insert(e1);
+    s.insert(e2);
+
+    set_t::iterator it = s.find(e1);
+    BOOST_TEST(it != s.end() && &*it == &e1);
+
+    it = s.find((void*)&v2, set_element::order_by_key());
+    BOOST_TEST(it != s.end() && &*it == &e2);
+
+    it = s.find(e3);
+    BOOST_TEST(it == s.end());
+
+    it = s.find((void*)&v3, set_element::order_by_key());
+    BOOST_TEST(it == s.end());
+
+    s.clear();
+}
+
+int main()
+{
+    test_set();
+
+    return boost::report_errors();
+}