Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 1 | /////////////////////////////////////////////////////////////////////////////// |
| 2 | // |
| 3 | // Copyright (c) 2015 Microsoft Corporation. All rights reserved. |
| 4 | // |
| 5 | // This code is licensed under the MIT License (MIT). |
| 6 | // |
| 7 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 8 | // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 9 | // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 10 | // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 11 | // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 12 | // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 13 | // THE SOFTWARE. |
| 14 | // |
| 15 | /////////////////////////////////////////////////////////////////////////////// |
| 16 | |
| 17 | #pragma once |
| 18 | |
| 19 | #ifndef GSL_SPAN_H |
| 20 | #define GSL_SPAN_H |
| 21 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 22 | #include <gsl/gsl_assert> |
| 23 | #include <gsl/gsl_byte> |
| 24 | #include <gsl/gsl_util> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 25 | |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 26 | #include <array> |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 27 | #include <iterator> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 28 | #include <limits> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 29 | #include <memory> |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 30 | #include <stdexcept> |
| 31 | #include <type_traits> |
| 32 | #include <utility> |
| 33 | |
| 34 | #ifdef _MSC_VER |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 35 | #pragma warning(push) |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 36 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 37 | // turn off some warnings that are noisy about our Expects statements |
| 38 | #pragma warning(disable : 4127) // conditional expression is constant |
Neil MacIntosh | b2ee484 | 2017-07-13 13:53:56 -0700 | [diff] [blame] | 39 | #pragma warning(disable : 4702) // unreachable code |
Neil MacIntosh | a9f0ce2 | 2016-03-31 12:01:07 -0700 | [diff] [blame] | 40 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 41 | // blanket turn off warnings from CppCoreCheck for now |
| 42 | // so people aren't annoyed by them when running the tool. |
| 43 | // more targeted suppressions will be added in a future update to the GSL |
| 44 | #pragma warning(disable : 26481 26482 26483 26485 26490 26491 26492 26493 26495) |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 45 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 46 | #if _MSC_VER < 1910 |
| 47 | #pragma push_macro("constexpr") |
| 48 | #define constexpr /*constexpr*/ |
Neil MacIntosh | a9f0ce2 | 2016-03-31 12:01:07 -0700 | [diff] [blame] | 49 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 50 | #endif // _MSC_VER < 1910 |
| 51 | #endif // _MSC_VER |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 52 | |
| 53 | #ifdef GSL_THROW_ON_CONTRACT_VIOLATION |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 54 | #define GSL_NOEXCEPT /*noexcept*/ |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 55 | #else |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 56 | #define GSL_NOEXCEPT noexcept |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 57 | #endif // GSL_THROW_ON_CONTRACT_VIOLATION |
| 58 | |
| 59 | namespace gsl |
| 60 | { |
| 61 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 62 | // [views.constants], constants |
Neil MacIntosh | c94a66f | 2016-06-12 18:28:19 -0700 | [diff] [blame] | 63 | constexpr const std::ptrdiff_t dynamic_extent = -1; |
| 64 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 65 | template <class ElementType, std::ptrdiff_t Extent = dynamic_extent> |
| 66 | class span; |
| 67 | |
Neil MacIntosh | c94a66f | 2016-06-12 18:28:19 -0700 | [diff] [blame] | 68 | // implementation details |
Neil MacIntosh | c40094a | 2016-03-01 12:11:41 -0800 | [diff] [blame] | 69 | namespace details |
| 70 | { |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 71 | template <class T> |
| 72 | struct is_span_oracle : std::false_type |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 73 | { |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 74 | }; |
| 75 | |
| 76 | template <class ElementType, std::ptrdiff_t Extent> |
| 77 | struct is_span_oracle<gsl::span<ElementType, Extent>> : std::true_type |
| 78 | { |
| 79 | }; |
| 80 | |
| 81 | template <class T> |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 82 | struct is_span : public is_span_oracle<std::remove_cv_t<T>> |
| 83 | { |
| 84 | }; |
| 85 | |
| 86 | template <class T> |
| 87 | struct is_std_array_oracle : std::false_type |
| 88 | { |
| 89 | }; |
| 90 | |
Casey Carter | 3819df6 | 2017-02-13 12:11:45 -0800 | [diff] [blame] | 91 | template <class ElementType, std::size_t Extent> |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 92 | struct is_std_array_oracle<std::array<ElementType, Extent>> : std::true_type |
| 93 | { |
| 94 | }; |
| 95 | |
| 96 | template <class T> |
| 97 | struct is_std_array : public is_std_array_oracle<std::remove_cv_t<T>> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 98 | { |
| 99 | }; |
| 100 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 101 | template <std::ptrdiff_t From, std::ptrdiff_t To> |
| 102 | struct is_allowed_extent_conversion |
Neil MacIntosh | 6fadce9 | 2016-07-26 19:19:47 -0700 | [diff] [blame] | 103 | : public std::integral_constant<bool, From == To || From == gsl::dynamic_extent || |
| 104 | To == gsl::dynamic_extent> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 105 | { |
| 106 | }; |
| 107 | |
| 108 | template <class From, class To> |
| 109 | struct is_allowed_element_type_conversion |
Neil MacIntosh | 831be5d | 2016-09-14 22:01:02 -0700 | [diff] [blame] | 110 | : public std::integral_constant<bool, std::is_convertible<From (*)[], To (*)[]>::value> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 111 | { |
| 112 | }; |
| 113 | |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 114 | template <class Span, bool IsConst> |
Neil MacIntosh | 6c7be2c | 2016-08-01 21:41:20 -0700 | [diff] [blame] | 115 | class span_iterator |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 116 | { |
Eric Niebler | 9d13cb1 | 2016-12-09 20:19:50 -0800 | [diff] [blame] | 117 | using element_type_ = typename Span::element_type; |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 118 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 119 | public: |
| 120 | using iterator_category = std::random_access_iterator_tag; |
Maciej T. Nowak | c2f953f | 2017-04-13 22:55:20 +0200 | [diff] [blame] | 121 | using value_type = std::remove_cv_t<element_type_>; |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 122 | using difference_type = typename Span::index_type; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 123 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 124 | using reference = std::conditional_t<IsConst, const element_type_, element_type_>&; |
Eric Niebler | 9d13cb1 | 2016-12-09 20:19:50 -0800 | [diff] [blame] | 125 | using pointer = std::add_pointer_t<reference>; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 126 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 127 | span_iterator() = default; |
Neil MacIntosh | 0dd5f56 | 2016-08-08 13:33:02 -0700 | [diff] [blame] | 128 | |
Galik | 7abfc98 | 2017-05-30 16:09:09 +0100 | [diff] [blame] | 129 | constexpr span_iterator(const Span* span, typename Span::index_type index) GSL_NOEXCEPT |
| 130 | : span_(span), index_(index) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 131 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 132 | Expects(span == nullptr || (index_ >= 0 && index <= span_->length())); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 133 | } |
| 134 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 135 | friend span_iterator<Span, true>; |
| 136 | template<bool B, std::enable_if_t<!B && IsConst>* = nullptr> |
| 137 | constexpr span_iterator(const span_iterator<Span, B>& other) GSL_NOEXCEPT |
Neil MacIntosh | 0dd5f56 | 2016-08-08 13:33:02 -0700 | [diff] [blame] | 138 | : span_iterator(other.span_, other.index_) |
| 139 | { |
| 140 | } |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 141 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 142 | constexpr reference operator*() const GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 143 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 144 | Expects(span_); |
| 145 | return (*span_)[index_]; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 146 | } |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 147 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 148 | constexpr pointer operator->() const GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 149 | { |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 150 | Expects(span_ && index_ >= 0 && index_ < span_->length()); |
| 151 | return span_->data() + index_; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 152 | } |
| 153 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 154 | constexpr span_iterator& operator++() GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 155 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 156 | Expects(span_ && index_ >= 0 && index_ < span_->length()); |
| 157 | ++index_; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 158 | return *this; |
| 159 | } |
| 160 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 161 | constexpr span_iterator operator++(int) GSL_NOEXCEPT |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 162 | { |
| 163 | auto ret = *this; |
| 164 | ++(*this); |
| 165 | return ret; |
| 166 | } |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 167 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 168 | constexpr span_iterator& operator--() GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 169 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 170 | Expects(span_ && index_ > 0 && index_ <= span_->length()); |
| 171 | --index_; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 172 | return *this; |
| 173 | } |
| 174 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 175 | constexpr span_iterator operator--(int) GSL_NOEXCEPT |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 176 | { |
| 177 | auto ret = *this; |
| 178 | --(*this); |
| 179 | return ret; |
| 180 | } |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 181 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 182 | constexpr span_iterator operator+(difference_type n) const GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 183 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 184 | auto ret = *this; |
| 185 | return ret += n; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 186 | } |
| 187 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 188 | constexpr span_iterator& operator+=(difference_type n) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 189 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 190 | Expects(span_ && (index_ + n) >= 0 && (index_ + n) <= span_->length()); |
| 191 | index_ += n; |
| 192 | return *this; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 193 | } |
| 194 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 195 | constexpr span_iterator operator-(difference_type n) const GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 196 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 197 | auto ret = *this; |
| 198 | return ret -= n; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 199 | } |
| 200 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 201 | constexpr span_iterator& operator-=(difference_type n) GSL_NOEXCEPT { return *this += -n; } |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 202 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 203 | constexpr difference_type operator-(const span_iterator& rhs) const GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 204 | { |
Neil MacIntosh | 94afa1f | 2016-08-01 18:49:48 -0700 | [diff] [blame] | 205 | Expects(span_ == rhs.span_); |
| 206 | return index_ - rhs.index_; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 207 | } |
| 208 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 209 | constexpr reference operator[](difference_type n) const GSL_NOEXCEPT |
| 210 | { |
| 211 | return *(*this + n); |
| 212 | } |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 213 | |
Neil MacIntosh | 0dd5f56 | 2016-08-08 13:33:02 -0700 | [diff] [blame] | 214 | constexpr friend bool operator==(const span_iterator& lhs, |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 215 | const span_iterator& rhs) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 216 | { |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 217 | return lhs.span_ == rhs.span_ && lhs.index_ == rhs.index_; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 218 | } |
| 219 | |
Neil MacIntosh | 0dd5f56 | 2016-08-08 13:33:02 -0700 | [diff] [blame] | 220 | constexpr friend bool operator!=(const span_iterator& lhs, |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 221 | const span_iterator& rhs) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 222 | { |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 223 | return !(lhs == rhs); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 224 | } |
| 225 | |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 226 | constexpr friend bool operator<(const span_iterator& lhs, |
| 227 | const span_iterator& rhs) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 228 | { |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 229 | Expects(lhs.span_ == rhs.span_); |
| 230 | return lhs.index_ < rhs.index_; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 231 | } |
| 232 | |
Neil MacIntosh | 0dd5f56 | 2016-08-08 13:33:02 -0700 | [diff] [blame] | 233 | constexpr friend bool operator<=(const span_iterator& lhs, |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 234 | const span_iterator& rhs) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 235 | { |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 236 | return !(rhs < lhs); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 237 | } |
| 238 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 239 | constexpr friend bool operator>(const span_iterator& lhs, |
| 240 | const span_iterator& rhs) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 241 | { |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 242 | return rhs < lhs; |
| 243 | } |
| 244 | |
Neil MacIntosh | 0dd5f56 | 2016-08-08 13:33:02 -0700 | [diff] [blame] | 245 | constexpr friend bool operator>=(const span_iterator& lhs, |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 246 | const span_iterator& rhs) GSL_NOEXCEPT |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 247 | { |
| 248 | return !(rhs > lhs); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 249 | } |
| 250 | |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 251 | protected: |
Casey Carter | 39902b6 | 2017-05-26 15:41:12 -0700 | [diff] [blame] | 252 | const Span* span_ = nullptr; |
| 253 | std::ptrdiff_t index_ = 0; |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 254 | }; |
| 255 | |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 256 | template <class Span, bool IsConst> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 257 | inline constexpr span_iterator<Span, IsConst> |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 258 | operator+(typename span_iterator<Span, IsConst>::difference_type n, |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 259 | const span_iterator<Span, IsConst>& rhs) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 260 | { |
| 261 | return rhs + n; |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 262 | } |
| 263 | |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 264 | template <class Span, bool IsConst> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 265 | inline constexpr span_iterator<Span, IsConst> |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 266 | operator-(typename span_iterator<Span, IsConst>::difference_type n, |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 267 | const span_iterator<Span, IsConst>& rhs) GSL_NOEXCEPT |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 268 | { |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 269 | return rhs - n; |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 270 | } |
| 271 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 272 | template <std::ptrdiff_t Ext> |
| 273 | class extent_type |
| 274 | { |
| 275 | public: |
Neil MacIntosh | 6fadce9 | 2016-07-26 19:19:47 -0700 | [diff] [blame] | 276 | using index_type = std::ptrdiff_t; |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 277 | |
| 278 | static_assert(Ext >= 0, "A fixed-size span must be >= 0 in size."); |
| 279 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 280 | constexpr extent_type() GSL_NOEXCEPT {} |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 281 | |
| 282 | template <index_type Other> |
Casey Carter | 96eaf27 | 2017-01-28 00:08:48 -0800 | [diff] [blame] | 283 | constexpr extent_type(extent_type<Other> ext) |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 284 | { |
| 285 | static_assert(Other == Ext || Other == dynamic_extent, |
| 286 | "Mismatch between fixed-size extent and size of initializing data."); |
| 287 | Expects(ext.size() == Ext); |
| 288 | } |
| 289 | |
| 290 | constexpr extent_type(index_type size) { Expects(size == Ext); } |
| 291 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 292 | constexpr index_type size() const GSL_NOEXCEPT { return Ext; } |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 293 | }; |
| 294 | |
| 295 | template <> |
| 296 | class extent_type<dynamic_extent> |
| 297 | { |
| 298 | public: |
Neil MacIntosh | 6fadce9 | 2016-07-26 19:19:47 -0700 | [diff] [blame] | 299 | using index_type = std::ptrdiff_t; |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 300 | |
| 301 | template <index_type Other> |
| 302 | explicit constexpr extent_type(extent_type<Other> ext) : size_(ext.size()) |
| 303 | { |
| 304 | } |
| 305 | |
| 306 | explicit constexpr extent_type(index_type size) : size_(size) { Expects(size >= 0); } |
| 307 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 308 | constexpr index_type size() const GSL_NOEXCEPT { return size_; } |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 309 | |
| 310 | private: |
| 311 | index_type size_; |
| 312 | }; |
Neil MacIntosh | c40094a | 2016-03-01 12:11:41 -0800 | [diff] [blame] | 313 | } // namespace details |
| 314 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 315 | // [span], class template span |
Neil MacIntosh | c40094a | 2016-03-01 12:11:41 -0800 | [diff] [blame] | 316 | template <class ElementType, std::ptrdiff_t Extent> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 317 | class span |
| 318 | { |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 319 | public: |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 320 | // constants and types |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 321 | using element_type = ElementType; |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 322 | using value_type = std::remove_cv_t<ElementType>; |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 323 | using index_type = std::ptrdiff_t; |
| 324 | using pointer = element_type*; |
| 325 | using reference = element_type&; |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 326 | |
Neil MacIntosh | 82389aa | 2016-08-08 12:06:47 -0700 | [diff] [blame] | 327 | using iterator = details::span_iterator<span<ElementType, Extent>, false>; |
| 328 | using const_iterator = details::span_iterator<span<ElementType, Extent>, true>; |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 329 | using reverse_iterator = std::reverse_iterator<iterator>; |
Neil MacIntosh | 2674724 | 2016-06-26 17:00:56 +0300 | [diff] [blame] | 330 | using const_reverse_iterator = std::reverse_iterator<const_iterator>; |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 331 | |
Maciej T. Nowak | c2f953f | 2017-04-13 22:55:20 +0200 | [diff] [blame] | 332 | using size_type = index_type; |
| 333 | |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 334 | constexpr static const index_type extent = Extent; |
| 335 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 336 | // [span.cons], span constructors, copy, assignment, and destructor |
Casey Carter | 96eaf27 | 2017-01-28 00:08:48 -0800 | [diff] [blame] | 337 | template <bool Dependent = false, |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 338 | // "Dependent" is needed to make "std::enable_if_t<Dependent || Extent <= 0>" SFINAE, |
| 339 | // since "std::enable_if_t<Extent <= 0>" is ill-formed when Extent is greater than 0. |
| 340 | class = std::enable_if_t<(Dependent || Extent <= 0)>> |
| 341 | constexpr span() GSL_NOEXCEPT : storage_(nullptr, details::extent_type<0>()) |
| 342 | { |
| 343 | } |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 344 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 345 | constexpr span(std::nullptr_t) GSL_NOEXCEPT : span() {} |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 346 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 347 | constexpr span(pointer ptr, index_type count) : storage_(ptr, count) {} |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 348 | |
Neil MacIntosh | 502cd66 | 2016-02-28 00:50:53 -0800 | [diff] [blame] | 349 | constexpr span(pointer firstElem, pointer lastElem) |
| 350 | : storage_(firstElem, std::distance(firstElem, lastElem)) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 351 | { |
| 352 | } |
Neil MacIntosh | f61a9bb | 2016-02-29 13:16:48 -0800 | [diff] [blame] | 353 | |
Casey Carter | 3819df6 | 2017-02-13 12:11:45 -0800 | [diff] [blame] | 354 | template <std::size_t N> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 355 | constexpr span(element_type (&arr)[N]) GSL_NOEXCEPT |
| 356 | : storage_(&arr[0], details::extent_type<N>()) |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 357 | { |
| 358 | } |
Neil MacIntosh | 6fadce9 | 2016-07-26 19:19:47 -0700 | [diff] [blame] | 359 | |
Casey Carter | 3819df6 | 2017-02-13 12:11:45 -0800 | [diff] [blame] | 360 | template <std::size_t N, class ArrayElementType = std::remove_const_t<element_type>> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 361 | constexpr span(std::array<ArrayElementType, N>& arr) GSL_NOEXCEPT |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 362 | : storage_(&arr[0], details::extent_type<N>()) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 363 | { |
| 364 | } |
| 365 | |
Casey Carter | 3819df6 | 2017-02-13 12:11:45 -0800 | [diff] [blame] | 366 | template <std::size_t N> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 367 | constexpr span(const std::array<std::remove_const_t<element_type>, N>& arr) GSL_NOEXCEPT |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 368 | : storage_(&arr[0], details::extent_type<N>()) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 369 | { |
| 370 | } |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 371 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 372 | template <class ArrayElementType = std::add_pointer<element_type>> |
| 373 | constexpr span(const std::unique_ptr<ArrayElementType>& ptr, index_type count) |
| 374 | : storage_(ptr.get(), count) |
| 375 | { |
| 376 | } |
Rian Quinn | 2b51b87 | 2016-11-03 19:55:41 -0600 | [diff] [blame] | 377 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 378 | constexpr span(const std::unique_ptr<ElementType>& ptr) : storage_(ptr.get(), ptr.get() ? 1 : 0) |
| 379 | { |
| 380 | } |
| 381 | constexpr span(const std::shared_ptr<ElementType>& ptr) : storage_(ptr.get(), ptr.get() ? 1 : 0) |
| 382 | { |
| 383 | } |
Rian Quinn | 2b51b87 | 2016-11-03 19:55:41 -0600 | [diff] [blame] | 384 | |
Neil MacIntosh | c40094a | 2016-03-01 12:11:41 -0800 | [diff] [blame] | 385 | // NB: the SFINAE here uses .data() as a incomplete/imperfect proxy for the requirement |
| 386 | // on Container to be a contiguous sequence container. |
| 387 | template <class Container, |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 388 | class = std::enable_if_t< |
Neil MacIntosh | 6fadce9 | 2016-07-26 19:19:47 -0700 | [diff] [blame] | 389 | !details::is_span<Container>::value && !details::is_std_array<Container>::value && |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 390 | std::is_convertible<typename Container::pointer, pointer>::value && |
| 391 | std::is_convertible<typename Container::pointer, |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 392 | decltype(std::declval<Container>().data())>::value>> |
Gary Furnish | 612747a | 2016-10-04 21:13:18 -0600 | [diff] [blame] | 393 | constexpr span(Container& cont) : span(cont.data(), narrow<index_type>(cont.size())) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 394 | { |
| 395 | } |
Neil MacIntosh | c40094a | 2016-03-01 12:11:41 -0800 | [diff] [blame] | 396 | |
Neil MacIntosh | c40094a | 2016-03-01 12:11:41 -0800 | [diff] [blame] | 397 | template <class Container, |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 398 | class = std::enable_if_t< |
| 399 | std::is_const<element_type>::value && !details::is_span<Container>::value && |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 400 | std::is_convertible<typename Container::pointer, pointer>::value && |
| 401 | std::is_convertible<typename Container::pointer, |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 402 | decltype(std::declval<Container>().data())>::value>> |
Gary Furnish | 612747a | 2016-10-04 21:13:18 -0600 | [diff] [blame] | 403 | constexpr span(const Container& cont) : span(cont.data(), narrow<index_type>(cont.size())) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 404 | { |
| 405 | } |
Neil MacIntosh | 3d4c349 | 2016-03-17 17:20:33 -0700 | [diff] [blame] | 406 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 407 | constexpr span(const span& other) GSL_NOEXCEPT = default; |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 408 | constexpr span(span&& other) GSL_NOEXCEPT = default; |
Neil MacIntosh | 717a2e3 | 2016-03-16 19:39:55 -0700 | [diff] [blame] | 409 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 410 | template < |
| 411 | class OtherElementType, std::ptrdiff_t OtherExtent, |
Neil MacIntosh | c94a66f | 2016-06-12 18:28:19 -0700 | [diff] [blame] | 412 | class = std::enable_if_t< |
| 413 | details::is_allowed_extent_conversion<OtherExtent, Extent>::value && |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 414 | details::is_allowed_element_type_conversion<OtherElementType, element_type>::value>> |
| 415 | constexpr span(const span<OtherElementType, OtherExtent>& other) |
Neil MacIntosh | 831be5d | 2016-09-14 22:01:02 -0700 | [diff] [blame] | 416 | : storage_(other.data(), details::extent_type<OtherExtent>(other.size())) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 417 | { |
| 418 | } |
| 419 | |
| 420 | template < |
| 421 | class OtherElementType, std::ptrdiff_t OtherExtent, |
| 422 | class = std::enable_if_t< |
| 423 | details::is_allowed_extent_conversion<OtherExtent, Extent>::value && |
| 424 | details::is_allowed_element_type_conversion<OtherElementType, element_type>::value>> |
Neil MacIntosh | 717a2e3 | 2016-03-16 19:39:55 -0700 | [diff] [blame] | 425 | constexpr span(span<OtherElementType, OtherExtent>&& other) |
Neil MacIntosh | 831be5d | 2016-09-14 22:01:02 -0700 | [diff] [blame] | 426 | : storage_(other.data(), details::extent_type<OtherExtent>(other.size())) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 427 | { |
| 428 | } |
Neil MacIntosh | 717a2e3 | 2016-03-16 19:39:55 -0700 | [diff] [blame] | 429 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 430 | ~span() GSL_NOEXCEPT = default; |
| 431 | constexpr span& operator=(const span& other) GSL_NOEXCEPT = default; |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 432 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 433 | constexpr span& operator=(span&& other) GSL_NOEXCEPT = default; |
Neil MacIntosh | be43c79 | 2017-07-14 04:40:27 -0700 | [diff] [blame] | 434 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 435 | // [span.sub], span subviews |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 436 | template <std::ptrdiff_t Count> |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 437 | constexpr span<element_type, Count> first() const |
| 438 | { |
| 439 | Expects(Count >= 0 && Count <= size()); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 440 | return {data(), Count}; |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 441 | } |
| 442 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 443 | template <std::ptrdiff_t Count> |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 444 | constexpr span<element_type, Count> last() const |
| 445 | { |
| 446 | Expects(Count >= 0 && Count <= size()); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 447 | return {data() + (size() - Count), Count}; |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 448 | } |
| 449 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 450 | template <std::ptrdiff_t Offset, std::ptrdiff_t Count = dynamic_extent> |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 451 | constexpr span<element_type, Count> subspan() const |
| 452 | { |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 453 | Expects((Offset == 0 || (Offset > 0 && Offset <= size())) && |
| 454 | (Count == dynamic_extent || (Count >= 0 && Offset + Count <= size()))); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 455 | return {data() + Offset, Count == dynamic_extent ? size() - Offset : Count}; |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 456 | } |
| 457 | |
| 458 | constexpr span<element_type, dynamic_extent> first(index_type count) const |
| 459 | { |
| 460 | Expects(count >= 0 && count <= size()); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 461 | return {data(), count}; |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 462 | } |
| 463 | |
| 464 | constexpr span<element_type, dynamic_extent> last(index_type count) const |
| 465 | { |
| 466 | Expects(count >= 0 && count <= size()); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 467 | return {data() + (size() - count), count}; |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 468 | } |
| 469 | |
| 470 | constexpr span<element_type, dynamic_extent> subspan(index_type offset, |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 471 | index_type count = dynamic_extent) const |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 472 | { |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 473 | Expects((offset == 0 || (offset > 0 && offset <= size())) && |
| 474 | (count == dynamic_extent || (count >= 0 && offset + count <= size()))); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 475 | return {data() + offset, count == dynamic_extent ? size() - offset : count}; |
Neil MacIntosh | c8a412f | 2016-03-18 16:49:29 -0700 | [diff] [blame] | 476 | } |
| 477 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 478 | // [span.obs], span observers |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 479 | constexpr index_type length() const GSL_NOEXCEPT { return size(); } |
| 480 | constexpr index_type size() const GSL_NOEXCEPT { return storage_.size(); } |
| 481 | constexpr index_type length_bytes() const GSL_NOEXCEPT { return size_bytes(); } |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 482 | constexpr index_type size_bytes() const GSL_NOEXCEPT |
| 483 | { |
| 484 | return size() * narrow_cast<index_type>(sizeof(element_type)); |
| 485 | } |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 486 | constexpr bool empty() const GSL_NOEXCEPT { return size() == 0; } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 487 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 488 | // [span.elem], span element access |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 489 | constexpr reference operator[](index_type idx) const |
| 490 | { |
Neil MacIntosh | 502cd66 | 2016-02-28 00:50:53 -0800 | [diff] [blame] | 491 | Expects(idx >= 0 && idx < storage_.size()); |
Neil MacIntosh | f2ab3a5 | 2016-07-20 09:24:49 -0700 | [diff] [blame] | 492 | return data()[idx]; |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 493 | } |
Rian Quinn | 6cffe0d | 2016-10-26 15:11:24 -0600 | [diff] [blame] | 494 | |
| 495 | constexpr reference at(index_type idx) const { return this->operator[](idx); } |
Neil MacIntosh | cc22f2b | 2016-02-25 11:42:26 -0800 | [diff] [blame] | 496 | constexpr reference operator()(index_type idx) const { return this->operator[](idx); } |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 497 | constexpr pointer data() const GSL_NOEXCEPT { return storage_.data(); } |
Neil MacIntosh | d9d6ff0 | 2016-05-29 13:52:28 -0700 | [diff] [blame] | 498 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 499 | // [span.iter], span iterator support |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 500 | iterator begin() const GSL_NOEXCEPT { return {this, 0}; } |
| 501 | iterator end() const GSL_NOEXCEPT { return {this, length()}; } |
Neil MacIntosh | 30a038c | 2016-07-18 11:38:01 -0700 | [diff] [blame] | 502 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 503 | const_iterator cbegin() const GSL_NOEXCEPT { return {this, 0}; } |
| 504 | const_iterator cend() const GSL_NOEXCEPT { return {this, length()}; } |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 505 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 506 | reverse_iterator rbegin() const GSL_NOEXCEPT { return reverse_iterator{end()}; } |
| 507 | reverse_iterator rend() const GSL_NOEXCEPT { return reverse_iterator{begin()}; } |
Neil MacIntosh | 30a038c | 2016-07-18 11:38:01 -0700 | [diff] [blame] | 508 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 509 | const_reverse_iterator crbegin() const GSL_NOEXCEPT { return const_reverse_iterator{cend()}; } |
| 510 | const_reverse_iterator crend() const GSL_NOEXCEPT { return const_reverse_iterator{cbegin()}; } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 511 | |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 512 | private: |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 513 | // this implementation detail class lets us take advantage of the |
Neil MacIntosh | 502cd66 | 2016-02-28 00:50:53 -0800 | [diff] [blame] | 514 | // empty base class optimization to pay for only storage of a single |
| 515 | // pointer in the case of fixed-size spans |
| 516 | template <class ExtentType> |
| 517 | class storage_type : public ExtentType |
| 518 | { |
| 519 | public: |
| 520 | template <class OtherExtentType> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 521 | constexpr storage_type(pointer data, OtherExtentType ext) : ExtentType(ext), data_(data) |
| 522 | { |
Neil MacIntosh | 4de3d4e | 2016-07-26 18:44:13 -0700 | [diff] [blame] | 523 | Expects((!data && ExtentType::size() == 0) || (data && ExtentType::size() >= 0)); |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 524 | } |
Neil MacIntosh | 502cd66 | 2016-02-28 00:50:53 -0800 | [diff] [blame] | 525 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 526 | constexpr pointer data() const GSL_NOEXCEPT { return data_; } |
Neil MacIntosh | 502cd66 | 2016-02-28 00:50:53 -0800 | [diff] [blame] | 527 | |
| 528 | private: |
| 529 | pointer data_; |
| 530 | }; |
| 531 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 532 | storage_type<details::extent_type<Extent>> storage_; |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 533 | }; |
| 534 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 535 | // [span.comparison], span comparison operators |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 536 | template <class ElementType, std::ptrdiff_t FirstExtent, std::ptrdiff_t SecondExtent> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 537 | inline constexpr bool operator==(const span<ElementType, FirstExtent>& l, |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 538 | const span<ElementType, SecondExtent>& r) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 539 | { |
| 540 | return std::equal(l.begin(), l.end(), r.begin(), r.end()); |
| 541 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 542 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 543 | template <class ElementType, std::ptrdiff_t Extent> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 544 | inline constexpr bool operator!=(const span<ElementType, Extent>& l, |
| 545 | const span<ElementType, Extent>& r) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 546 | { |
| 547 | return !(l == r); |
| 548 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 549 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 550 | template <class ElementType, std::ptrdiff_t Extent> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 551 | inline constexpr bool operator<(const span<ElementType, Extent>& l, |
| 552 | const span<ElementType, Extent>& r) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 553 | { |
| 554 | return std::lexicographical_compare(l.begin(), l.end(), r.begin(), r.end()); |
| 555 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 556 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 557 | template <class ElementType, std::ptrdiff_t Extent> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 558 | inline constexpr bool operator<=(const span<ElementType, Extent>& l, |
| 559 | const span<ElementType, Extent>& r) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 560 | { |
| 561 | return !(l > r); |
| 562 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 563 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 564 | template <class ElementType, std::ptrdiff_t Extent> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 565 | inline constexpr bool operator>(const span<ElementType, Extent>& l, |
| 566 | const span<ElementType, Extent>& r) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 567 | { |
| 568 | return r < l; |
| 569 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 570 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 571 | template <class ElementType, std::ptrdiff_t Extent> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 572 | inline constexpr bool operator>=(const span<ElementType, Extent>& l, |
| 573 | const span<ElementType, Extent>& r) |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 574 | { |
| 575 | return !(l < r); |
| 576 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 577 | |
Neil MacIntosh | ba8ebef | 2016-05-29 17:06:29 -0700 | [diff] [blame] | 578 | namespace details |
| 579 | { |
| 580 | // if we only supported compilers with good constexpr support then |
| 581 | // this pair of classes could collapse down to a constexpr function |
| 582 | |
Casey Carter | 3819df6 | 2017-02-13 12:11:45 -0800 | [diff] [blame] | 583 | // we should use a narrow_cast<> to go to std::size_t, but older compilers may not see it as |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 584 | // constexpr |
Neil MacIntosh | ba8ebef | 2016-05-29 17:06:29 -0700 | [diff] [blame] | 585 | // and so will fail compilation of the template |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 586 | template <class ElementType, std::ptrdiff_t Extent> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 587 | struct calculate_byte_size |
| 588 | : std::integral_constant<std::ptrdiff_t, |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 589 | static_cast<std::ptrdiff_t>(sizeof(ElementType) * |
Neil MacIntosh | 6fadce9 | 2016-07-26 19:19:47 -0700 | [diff] [blame] | 590 | static_cast<std::size_t>(Extent))> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 591 | { |
| 592 | }; |
Neil MacIntosh | ba8ebef | 2016-05-29 17:06:29 -0700 | [diff] [blame] | 593 | |
| 594 | template <class ElementType> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 595 | struct calculate_byte_size<ElementType, dynamic_extent> |
| 596 | : std::integral_constant<std::ptrdiff_t, dynamic_extent> |
| 597 | { |
| 598 | }; |
Neil MacIntosh | ba8ebef | 2016-05-29 17:06:29 -0700 | [diff] [blame] | 599 | } |
| 600 | |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 601 | // [span.objectrep], views of object representation |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 602 | template <class ElementType, std::ptrdiff_t Extent> |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 603 | span<const byte, details::calculate_byte_size<ElementType, Extent>::value> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 604 | as_bytes(span<ElementType, Extent> s) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 605 | { |
| 606 | return {reinterpret_cast<const byte*>(s.data()), s.size_bytes()}; |
| 607 | } |
Neil MacIntosh | d3929c5 | 2016-02-24 16:11:33 -0800 | [diff] [blame] | 608 | |
Neil MacIntosh | c366f44 | 2016-07-26 18:34:27 -0700 | [diff] [blame] | 609 | template <class ElementType, std::ptrdiff_t Extent, |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 610 | class = std::enable_if_t<!std::is_const<ElementType>::value>> |
| 611 | span<byte, details::calculate_byte_size<ElementType, Extent>::value> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 612 | as_writeable_bytes(span<ElementType, Extent> s) GSL_NOEXCEPT |
Neil MacIntosh | b03b04b | 2016-07-20 13:17:47 -0700 | [diff] [blame] | 613 | { |
| 614 | return {reinterpret_cast<byte*>(s.data()), s.size_bytes()}; |
| 615 | } |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 616 | |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 617 | // |
| 618 | // make_span() - Utility functions for creating spans |
| 619 | // |
| 620 | template <class ElementType> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 621 | span<ElementType> make_span(ElementType* ptr, typename span<ElementType>::index_type count) |
| 622 | { |
| 623 | return span<ElementType>(ptr, count); |
| 624 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 625 | |
| 626 | template <class ElementType> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 627 | span<ElementType> make_span(ElementType* firstElem, ElementType* lastElem) |
| 628 | { |
| 629 | return span<ElementType>(firstElem, lastElem); |
| 630 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 631 | |
Casey Carter | 3819df6 | 2017-02-13 12:11:45 -0800 | [diff] [blame] | 632 | template <class ElementType, std::size_t N> |
ewoudvc | 64c0ca6 | 2017-04-25 21:01:49 +0200 | [diff] [blame] | 633 | span<ElementType, N> make_span(ElementType (&arr)[N]) |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 634 | { |
ewoudvc | 64c0ca6 | 2017-04-25 21:01:49 +0200 | [diff] [blame] | 635 | return span<ElementType, N>(arr); |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 636 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 637 | |
| 638 | template <class Container> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 639 | span<typename Container::value_type> make_span(Container& cont) |
| 640 | { |
| 641 | return span<typename Container::value_type>(cont); |
| 642 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 643 | |
| 644 | template <class Container> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 645 | span<const typename Container::value_type> make_span(const Container& cont) |
| 646 | { |
| 647 | return span<const typename Container::value_type>(cont); |
| 648 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 649 | |
| 650 | template <class Ptr> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 651 | span<typename Ptr::element_type> make_span(Ptr& cont, std::ptrdiff_t count) |
| 652 | { |
| 653 | return span<typename Ptr::element_type>(cont, count); |
| 654 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 655 | |
| 656 | template <class Ptr> |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 657 | span<typename Ptr::element_type> make_span(Ptr& cont) |
| 658 | { |
| 659 | return span<typename Ptr::element_type>(cont); |
| 660 | } |
Rian Quinn | 2df9f85 | 2016-11-16 11:17:04 -0700 | [diff] [blame] | 661 | |
ericLemanissier | 134f2db | 2016-08-23 10:30:06 +0200 | [diff] [blame] | 662 | // Specialization of gsl::at for span |
| 663 | template <class ElementType, std::ptrdiff_t Extent> |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 664 | inline constexpr ElementType& at(const span<ElementType, Extent>& s, std::ptrdiff_t index) |
ericLemanissier | 134f2db | 2016-08-23 10:30:06 +0200 | [diff] [blame] | 665 | { |
| 666 | // No bounds checking here because it is done in span::operator[] called below |
| 667 | return s[index]; |
| 668 | } |
| 669 | |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 670 | } // namespace gsl |
| 671 | |
Casey Carter | 4e8f95b | 2017-02-07 15:59:37 -0800 | [diff] [blame] | 672 | #undef GSL_NOEXCEPT |
| 673 | |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 674 | #ifdef _MSC_VER |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 675 | #if _MSC_VER < 1910 |
| 676 | #undef constexpr |
| 677 | #pragma pop_macro("constexpr") |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 678 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 679 | #endif // _MSC_VER < 1910 |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 680 | |
Tiago | ebe7ebf | 2017-04-20 07:51:37 -0700 | [diff] [blame] | 681 | #pragma warning(pop) |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 682 | #endif // _MSC_VER |
| 683 | |
Neil MacIntosh | cec26a2 | 2016-02-24 11:26:28 -0800 | [diff] [blame] | 684 | #endif // GSL_SPAN_H |