// { dg-options "-std=gnu++20" } | |
// { dg-do compile { target c++20 } } | |
#include <format> | |
struct O { | |
using difference_type = std::ranges::__detail::__max_diff_type; | |
O& operator=(const char&); | |
O& operator*(); | |
O& operator++(); | |
O& operator++(int); | |
}; | |
auto str = std::format_to_n(O{}, 4, "{}", " "); // PR libstdc++/107871 |