| 22 | template<typename I, typename S = I> |
| 23 | #endif |
| 24 | struct subrange : detail::stl_interfaces::view_interface<subrange<I, S>> |
| 25 | { |
| 26 | constexpr subrange() = default; |
| 27 | constexpr subrange(I first, S last) : first_(first), last_(last) {} |
| 28 | template<typename R> |
| 29 | constexpr explicit subrange(R const & r) : |
| 30 | first_(detail::text::detail::begin(r)), |
| 31 | last_(detail::text::detail::end(r)) |
| 32 | {} |
| 33 | |
| 34 | constexpr I begin() const { return first_; } |
| 35 | constexpr S end() const { return last_; } |
| 36 | |
| 37 | [[nodiscard]] constexpr subrange next(std::ptrdiff_t n = 1) const |
| 38 | { |
| 39 | return subrange{detail::text::detail::next(first_), last_}; |
| 40 | } |
| 41 | [[nodiscard]] constexpr subrange prev(std::ptrdiff_t n = 1) const |
| 42 | { |
| 43 | return subrange{detail::text::detail::prev(first_), last_}; |
| 44 | } |
| 45 | |
| 46 | constexpr subrange & advance(std::ptrdiff_t n) |
| 47 | { |
| 48 | std::advance(first_, n); |
| 49 | return *this; |
| 50 | } |
| 51 | |
| 52 | template< |
| 53 | typename I2, |
| 54 | typename S2, |
| 55 | typename Enable = std::enable_if_t< |
| 56 | std::is_convertible<I, I2>::value && |
| 57 | std::is_convertible<S, S2>::value>> |
| 58 | constexpr operator subrange<I2, S2>() const |
| 59 | { |
| 60 | return {first_, last_}; |
| 61 | } |
| 62 | |
| 63 | private: |
| 64 | I first_; |
| 65 | [[no_unique_address]] S last_; |
| 66 | }; |
| 67 | |
| 68 | #if defined(__cpp_deduction_guides) |
| 69 | #if BOOST_PARSER_USE_CONCEPTS |