no match for 'operator=' (operand types are 'const rxcpp::util::error_ptr' {aka 'const std::__exception_ptr::exception_ptr'} and 'std::remove_reference<const std::__exception_ptr::exception_ptr&>::type' {aka 'const std::__exception_ptr::exception_ptr'})

[HOMODELUNA]

Position

error: In file included from /root/mock-ability/build/.packages/r/rxcpp/9002d9be/725e51fe81b74141ade9efbd3ccaf900/include/rxcpp/rx-includes.hpp:206,
                 from /root/mock-ability/build/.packages/r/rxcpp/9002d9be/725e51fe81b74141ade9efbd3ccaf900/include/rxcpp/rx.hpp:8,
                 from /tmp/.xmake0/250305/_F49A970EF5E44D8A9D9305921FD57B9F.cpp:4:
/root/mock-ability/build/.packages/r/rxcpp/9002d9be/725e51fe81b74141ade9efbd3ccaf900/include/rxcpp/rx-notification.hpp: In member function 'rxcpp::notifications::notification<T>::on_error_notification& rxcpp::notifications::notification<T>::on_error_notification::operator=(rxcpp::notifications::notification<T>::on_error_notification)':
/root/mock-ability/build/.packages/r/rxcpp/9002d9be/725e51fe81b74141ade9efbd3ccaf900/include/rxcpp/rx-notification.hpp:153:88: error: no match for 'operator=' (operand types are 'const rxcpp::util::error_ptr' {aka 'const std::__exception_ptr::exception_ptr'} and 'std::remove_reference<const std::__exception_ptr::exception_ptr&>::type' {aka 'const std::__exception_ptr::exception_ptr'})
  153 |         on_error_notification& operator=(on_error_notification o) { ep = std::move(o.ep); return *this; }
      |  

Problem

in rx-hotification.hpp, on_error_notification has a const error_ptr, it can't e reassigned:

    struct on_error_notification : public base {
        on_error_notification(rxu::error_ptr ep) : ep(ep) {
        }
        on_error_notification(const on_error_notification& o) : ep(o.ep) {}
        on_error_notification(const on_error_notification&& o) : ep(std::move(o.ep)) {}
        // here reassigned a const std::exception_ptr
        on_error_notification& operator=(on_error_notification o) { ep = std::move(o.ep); return *this; }
        void out(std::ostream& os) const override {
            os << "on_error(";
            os << rxu::what(ep);
            os << ")";
        }
        bool equals(const typename base::type& other) const override {
            bool result = false;
            // not trying to compare exceptions
            other->accept(make_subscriber<T>(make_observer_dynamic<T>([](T){}, [&result](rxu::error_ptr){
                result = true;
            })));
            return result;
        }
        void accept(const typename base::observer_type& o) const & override{
            o.on_error(ep);
        }

        void accept(const typename base::observer_type& o) && override{
            o.on_error(ep);
        }
        const rxu::error_ptr ep; // it is declared as const
    };

Solution(maybe)

is this error_ptr defined const on_purpose? if not, maybe it should be declared without const.

[HOMODELUNA]

#612

here is the corresponding PR