| 1 | #include <array> |
| 2 | #include <span> |
| 3 | #include <stdio.h> |
| 4 | #include <string> |
| 5 | #include <vector> |
| 6 | |
| 7 | template <class T, size_t N> |
| 8 | void by_ref_and_ptr(std::span<T, N> &ref, std::span<T, N> *ptr) { |
| 9 | printf("Stop here to check by ref" ); |
| 10 | return; |
| 11 | } |
| 12 | |
| 13 | int main() { |
| 14 | std::array numbers = {1, 12, 123, 1234, 12345}; |
| 15 | |
| 16 | using dynamic_string_span = std::span<std::string>; |
| 17 | |
| 18 | // Test span of ints |
| 19 | |
| 20 | // Full view of numbers with static extent |
| 21 | std::span numbers_span = numbers; |
| 22 | |
| 23 | printf(format: "break here" ); |
| 24 | |
| 25 | by_ref_and_ptr(numbers_span, &numbers_span); |
| 26 | |
| 27 | // Test spans of strings |
| 28 | std::vector<std::string> strings{"goofy" , "is" , "smart" , "!!!" }; |
| 29 | strings.reserve(n: strings.size() + 1); |
| 30 | |
| 31 | // Partial view of strings with dynamic extent |
| 32 | dynamic_string_span strings_span{std::span{strings}.subspan(2)}; |
| 33 | |
| 34 | auto strings_span_it = strings_span.begin(); |
| 35 | |
| 36 | printf(format: "break here" ); |
| 37 | |
| 38 | // Vector size doesn't increase, span should |
| 39 | // print unchanged and the strings_span_it |
| 40 | // remains valid |
| 41 | strings.emplace_back(args: "???" ); |
| 42 | |
| 43 | printf(format: "break here" ); |
| 44 | |
| 45 | // Now some empty spans |
| 46 | std::span<int, 0> static_zero_span; |
| 47 | std::span<int> dynamic_zero_span; |
| 48 | |
| 49 | // Multiple spans |
| 50 | std::array span_arr{strings_span, strings_span}; |
| 51 | std::span<std::span<std::string>, 2> nested = span_arr; |
| 52 | |
| 53 | printf(format: "break here" ); |
| 54 | |
| 55 | return 0; // break here |
| 56 | } |
| 57 | |