63   template<class _Pair, class _Iter, class _Sent>
66     constructible_from<_Pair, _Iter, _Sent> &&
68     convertible_to<_Sent, tuple_element_t<1, _Pair>>;
72   template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent = _Iter,
73            subrange_kind _Kind = sized_sentinel_for<_Sent, _Iter>
76     requires (_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _Iter>)
78     : public view_interface<subrange<_Iter, _Sent, _Kind>>
82 …static constexpr bool _StoreSize = (_Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _I…
89     _LIBCPP_NO_UNIQUE_ADDRESS _Sent __end_ = _Sent();
97     constexpr subrange(__convertible_to_non_slicing<_Iter> auto __iter, _Sent __sent)  in subrange()
103     constexpr subrange(__convertible_to_non_slicing<_Iter> auto __iter, _Sent __sent,  in subrange()
108       if constexpr (sized_sentinel_for<_Sent, _Iter>)  in subrange()
116                convertible_to<sentinel_t<_Range>, _Sent>
126                convertible_to<sentinel_t<_Range>, _Sent>
135                convertible_to<sentinel_t<_Range>, _Sent>
143       requires __pair_like_convertible_from<_Pair, const _Iter&, const _Sent&>
159     constexpr _Sent end() const {  in end()
216   template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent>
217   subrange(_Iter, _Sent) -> subrange<_Iter, _Sent>;
219   template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent>
220   subrange(_Iter, _Sent, make_unsigned_t<iter_difference_t<_Iter>>)
221     -> subrange<_Iter, _Sent, subrange_kind::sized>;
232   template<size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
235   constexpr auto get(const subrange<_Iter, _Sent, _Kind>& __subrange) {  in get()  argument
242   template<size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
245   constexpr auto get(subrange<_Iter, _Sent, _Kind>&& __subrange) {  in get()  argument