| 137 | /// Space complexity: \Omega(1) |
| 138 | template<class InputIterator> |
| 139 | inline bool next_permutation(InputIterator first, |
| 140 | InputIterator last, |
| 141 | command_queue &queue = system::default_queue()) |
| 142 | { |
| 143 | BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value); |
| 144 | typedef typename std::iterator_traits<InputIterator>::value_type value_type; |
| 145 | |
| 146 | if(first == last) return false; |
| 147 | |
| 148 | InputIterator first_element = |
| 149 | detail::next_permutation_helper(first, last, queue); |
| 150 | |
| 151 | if(first_element == last) |
| 152 | { |
| 153 | reverse(first, last, queue); |
| 154 | return false; |
| 155 | } |
| 156 | |
| 157 | value_type first_value = first_element.read(queue); |
| 158 | |
| 159 | InputIterator ceiling_element = |
| 160 | detail::np_ceiling(first_element + 1, last, first_value, queue); |
| 161 | |
| 162 | value_type ceiling_value = ceiling_element.read(queue); |
| 163 | |
| 164 | first_element.write(ceiling_value, queue); |
| 165 | ceiling_element.write(first_value, queue); |
| 166 | |
| 167 | reverse(first_element + 1, last, queue); |
| 168 | |
| 169 | return true; |
| 170 | } |
| 171 | |
| 172 | } // end compute namespace |
| 173 | } // end boost namespace |