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 2 TS)
Extensions for parallelism (parallelism TS)
Extensions for concurrency (concurrency TS)
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Ranges (ranges TS)
Special mathematical functions (special math TR)
 
 
Iterators library
Iterator concepts
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Common algorithm requirements
                                                  
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projected
Iterator utilities and operations
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Stream iterators
Range access
Range primitives
 
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.