std::experimental::ranges::projected

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< cpp‎ | experimental‎ | ranges
 
 
Technical specifications
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Extensions for concurrency 2 (concurrency TS v2)
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Iterators library
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Concept utilities
projected
Iterator utilities and operations
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template< Readable I, IndirectRegularUnaryInvocable<I> Proj >

struct projected {
    using value_type =
        std::remove_cv_t<std::remove_reference_t<ranges::indirect_result_of_t<Proj&(I)>>>;
    ranges::indirect_result_of_t<Proj&(I)> operator*() const;
};

template< WeaklyIncrementable I, class Proj >
struct difference_type<projected<I, Proj>> {
    using type = ranges::difference_type_t<I>;

};
(ranges TS)

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.