The C++17 standard is feature complete and has been proposed for standardization. In compilers with experimental support for these features, it is usually referred to as C++1z.
auto[[fallthrough]], [[nodiscard]], [[maybe_unused]]static_assertif and switch[if constexpr](<https://stackoverflow.com/documentation/c%2B%2B/3899/constexpr/28625/static-if-statement>)[std::optional](<http://stackoverflow.com/documentation/c%2B%2B/2423/optionals>)[std::variant](<http://stackoverflow.com/documentation/c%2B%2B/5239/stdvariant>)[std::string_view](<http://stackoverflow.com/documentation/c%2B%2B/488/stdstring/6571/using-the-stdstring-view-class>)merge() and extract() for associative containers