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std::experimental::ranges:: Readable

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C++
Experimental
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Iterators library
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template < class In >

concept bool Readable =
requires {
typename ranges :: value_type_t < In > ;
typename ranges :: reference_t < In > ;
typename ranges :: rvalue_reference_t < In > ;
} &&
CommonReference < ranges :: reference_t < In > && , ranges :: value_type_t < In > & > &&
CommonReference < ranges :: reference_t < In > && , ranges :: rvalue_reference_t < In > && > &&

CommonReference < ranges :: rvalue_reference_t < In > && , const ranges :: value_type_t < In > & > ;
(ranges TS)

Readable という概念は、 operator* を適用することで読み取り可能な型（ポインタ、スマートポインタ、イテレータなど）によって満たされます。