# std::ranges::safe_iterator_t, std::ranges::safe_subrange_t

From cppreference.com
< cpp‎ | ranges

Defined in header `<ranges>` |  |
template<Range R> using safe_iterator_t = std::conditional_t<__ForwardingRange<R>, ranges::iterator_t<R>, ranges::dangling>; | (1) | (since C++20)
template<Range R> using safe_subrange_t = std::conditional_t<__ForwardingRange<R>, ranges::subrange<ranges::iterator_t<R>>, ranges::dangling>; | (2) | (since C++20)

1) Same as `ranges::iterator_t` when `R` models exposition-only concept `__ForwardingRange`, otherwise yields `ranges::dangling` instead.
2) Similar to (1), but it yields a specialization of `ranges::subrange` when the the same condition is met.

These two alias templates are used by some constrained algorithms to avoid returning potentially dangling iterators or views.

### See also

dangling | a placeholder type indicating that an iterator or a `subrange` should not be returned since it would be dangling (class)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/ranges/safe_iterator_t&oldid=110607"