88 struct StrictBooleanIterator {  struct
92   constexpr StrictBooleanIterator() = default;  argument
93   constexpr explicit StrictBooleanIterator(It it) : iter_(it) {}  in StrictBooleanIterator()  argument
96   constexpr StrictBooleanIterator& operator++() {
100   constexpr StrictBooleanIterator operator++(int) {
105   constexpr StrictBooleanIterator& operator--() {  argument
109   constexpr StrictBooleanIterator operator--(int) {
114   constexpr StrictBooleanIterator& operator+=(difference_type n) {  argument
118   constexpr StrictBooleanIterator& operator-=(difference_type n) {
122   friend constexpr StrictBooleanIterator operator+(StrictBooleanIterator x, difference_type n) {
126   friend constexpr StrictBooleanIterator operator+(difference_type n, StrictBooleanIterator x) {
130   friend constexpr StrictBooleanIterator operator-(StrictBooleanIterator x, difference_type n) {
134   friend constexpr difference_type operator-(StrictBooleanIterator x, StrictBooleanIterator y) {
137   constexpr BooleanTestable const& operator==(StrictBooleanIterator const& other) const {
140   constexpr BooleanTestable const& operator!=(StrictBooleanIterator const& other) const {
143   constexpr BooleanTestable const& operator<(StrictBooleanIterator const& other) const {
146   constexpr BooleanTestable const& operator<=(StrictBooleanIterator const& other) const {
149   constexpr BooleanTestable const& operator>(StrictBooleanIterator const& other) const {
152   constexpr BooleanTestable const& operator>=(StrictBooleanIterator const& other) const {
159 static_assert(std::forward_iterator<StrictBooleanIterator<int*>>);
160 static_assert(std::sentinel_for<StrictBooleanIterator<int*>, StrictBooleanIterator<int*>>);