std::ranges::subrange_kind
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                    |   Defined in header  <ranges>
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|   enum class subrange_kind : bool {     unsized,  | 
(since C++20) | |
Specifies if a std::ranges::subrange models std::ranges::sized_range or not.
Constants
| Name | Explanation | 
 unsized
 | 
 specifies that the subrange does not model sized_range
 | 
 sized
 | 
 specifies that the subrange does model sized_range
 |