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

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< 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)

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