Add some more cases for the serialization test of expectations

Make sure the various constraint names/values are kept (they are stored type-erased!)

test/detail/test_function.cpp

@@ -750,11 +750,18 @@ BOOST_FIXTURE_TEST_CASE(expectation_can_be_serialized_to_be_human_readable, mock
     {
         mock::detail::function<void(int)> f;
         f.expect().once().with(1);
-        f.expect().once().with(2);
+        f.expect().once().with(mock::close(3, 1));
+        int target = 0;
+        f.expect().once().with(mock::retrieve(target));
+        f.expect().once().with(mock::same(target));
         BOOST_CHECK_NO_THROW(f(2));
-        const std::string expected = "?\n"
-                                     ". once().with( 1 )\n"
-                                     "v once().with( 2 )";
+        std::string expected = "?\n";                   // Not in a current call context
+        expected += ". once().with( 1 )\n";             // Unmet/Unverified expectation with value
+        expected += "v once().with( close( 3, 1 ) )\n"; // Verified expectation with constraint
+        target = 42;
+        // (Unverified) expectation with retrieve/same constraint print current value
+        expected += ". once().with( retrieve( 42 ) )\n";
+        expected += ". once().with( same( 42 ) )";
         BOOST_CHECK_EQUAL(expected, to_string(f));
         CHECK_CALLS(1);
         f.reset();