# std::experimental::ranges::projected

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< cpp‎ | experimental‎ | ranges

Defined in header `<experimental/ranges/iterator>` |  |
template <ranges::Readable I, ranges::IndirectRegularInvocable<I> Proj> struct projected { using value_type = std::decay_t<ranges::indirect_result_of_t<Proj&(I)>>; ranges::indirect_result_of_t<Proj&(I)> operator*() const; }; template <ranges::WeaklyIncrementable I, class Proj> struct difference_type<projected<I, Proj>> { using type = ranges::difference_type_t<I>; }; |  |

The class template `projected` bundles a `Readable` type `I` and a function `Proj` into a new `Readable` type whose `reference` type is the result of applying `Proj` to the `reference` type of `I`. It exists solely to ease constraint specification, and so its operator*() may not be actually defined.

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