std::experimental::ranges::IndirectlySwappable

在标头 `<experimental/ranges/iterator>` 定义
template <class I1, class I2 = I1> concept bool IndirectlySwappable = ranges::Readable<I1> && ranges::Readable<I2> && requires(I1&& i1, I2&& i2) { ranges::iter_swap(std::forward<I1>(i1), std::forward<I2>(i2)); ranges::iter_swap(std::forward<I2>(i2), std::forward<I1>(i1)); ranges::iter_swap(std::forward<I1>(i1), std::forward<I1>(i1)); ranges::iter_swap(std::forward<I2>(i2), std::forward<I2>(i2)); };		(范围 TS)

本节未完成
原因：添加描述和额外通告