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## Abstract This pull request implements LWG3715: `view_interface::empty` is overconstrained. Here is an example similar to those described in the report, which compiles with `-stdlib=libstdc++` but failed to compile with `-stdlib=libc++`: ```cpp // https://godbolt.org/z/EWEoTzah3 std::istringstream input("1 2 3 4 5"); auto i = std::views::istream<int>(input); auto r = std::views::counted(i.begin(), 4) | std::views::take(2); assert(!r.empty()); ``` ## Reference - [Draft C++ Standard: [view.interface.general]](https://eel.is/c++draft/view.interface.general) - [LWG3715](https://wg21.link/LWG3715)