#define DOCTEST_CONFIG_DOUBLE_STRINGIFY #include DOCTEST_MAKE_STD_HEADERS_CLEAN_FROM_WARNINGS_ON_WALL_BEGIN #include DOCTEST_MAKE_STD_HEADERS_CLEAN_FROM_WARNINGS_ON_WALL_END namespace App { struct Foo { }; static std::string toString(Foo*) { return "Foo"; } } TEST_CASE("toString std::string ret type") { App::Foo foo; CHECK(&foo != nullptr); CHECK_NE(&foo, nullptr); CHECK(&foo); }