Update testclass.cpp

Author: chrchr-github

test/testclass.cpp

@@ -8119,6 +8119,21 @@ class TestClass : public TestFixture {
                                      "    std::string st;\n"
                                      "};");
         ASSERT_EQUALS("", errout_str());
+
+        checkInitializationListUsage("struct S {\n" // #14189
+                                     "    S() {}\n"
+                                     "    int i{};\n"
+                                     "};\n"
+                                     "struct T { explicit T(const S&); };\n"
+                                     "class C {\n"
+                                     "    C() {\n"
+                                     "        S s;\n"
+                                     "        s.i = 1;\n"
+                                     "        p = std::make_unique<T>(s);
+                                     "    }\n"
+                                     "    std::unique_ptr<T> p;\n"
+                                     "};");
+        ASSERT_EQUALS("", errout_str());
     }