std::is_error_condition_enum<std::future_errc>
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                    < cpp | thread | future errc
                    
                                                            
                    | Defined in header  <future> | ||
| template<> struct is_error_condition_enum<std::future_errc> : std::true_type; | (since C++11) | |
Specifies that std::future_errc is an error condition enum. This enables std::error_code and std::error_condition automatic conversions.
[edit] See also
| (C++11) | identifies an enumeration as an std::error_condition (class template) |