std::experimental::ranges::Semiregular
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                    < cpp | experimental | ranges
                    
                                                            
                    | Defined in header  <experimental/ranges/concepts> | ||
| template <class T> concept bool Semiregular = Copyable<T> && DefaultConstructible<T>; | (ranges TS) | |
The Semiregular concept specifies that a type is both copyable and default constructible. It is satisfied by types that behave similarly to built-in types like int, except that they need not support comparison with ==.