namespace std {
class future_error : public logic_error {
public:
explicit future_error(future_errc e);
const error_code& code() const noexcept;
const char* what() const noexcept;
private:
error_code ec_; // exposition only
};
}
explicit future_error(future_errc e);
Effects: Constructs an object of class future_error and initializes ec_ with make_error_code(e).
const error_code& code() const noexcept;
const char* what() const noexcept;