Dynamic memory allocation causing SIGSEGV (Signal: segmentation violation), In attempt to work with malloc and free

Question

I am creating a mathematical data structure in c++20 (Mingw-w64 clion) which i can partially offload from memory to storage and vice versa, Due to its capacity and size. While learning how i could work with memory i tested a particular code which to my knowledge it should work. But the app crashes due to segmentation violation (SIGSEGV) and i could not deduce why so. I would really appreciate your help.

//Utility
template<typename C, typename T>
std::basic_ostream<C, T> &
operator<<(std::basic_ostream<C, T> &_out, const logics::atomic_logic &_s) {
    _out << _s.to_string();
    return _out;
}

The following is not working.

int main() {
    using namespace std;
    using namespace logics;
    auto *pointer = (logic_sym *) malloc(sizeof(logic_sym));
    *pointer = logic_sym(26);
    std::cout << (*pointer) << std::endl;
    free(pointer);
    return 0;
}

yet the others below are working.
this one:-

int test2() {
    using namespace std;
    using namespace logics;
    auto *pointer = (logic_sym *) malloc(sizeof(logic_sym));
    *pointer = logic_sym(26);
    string s=pointer->to_string();
    std::cout << s<< std::endl;
    free(pointer);
    return 0;
}

and this:-

int test3() {
    using namespace std;
    using namespace logics;
    auto *pointer = new logic_sym(26u);
    *pointer = logic_sym(26u);
    std::cout << *pointer << std::endl;
    free(pointer);
    return 0;
}

EDIT The atomic_logic is not quite important but below is the logic_sym.

    struct logic_sym  final : public atomic_logic {
        [[nodiscard]] constexpr bool cached() const override {
            return false;
        };

        [[nodiscard]] const logic_id &get_id() const override {
            return id;
        }

        [[nodiscard]] constexpr logic_type get_type() const override {
            return logic_type::sym_t;
        }

        constexpr int operator<=>(const logic_id &_id) const override {
            return id - _id;
        }

        [[nodiscard]] std::string to_string() const override {
            if (id > 26)
                return (std::string("p") + std::to_string(id));
            return (std::string() + ((char) (id + 'a' - 1)));
        }

        [[maybe_unused]] explicit logic_sym(const logic_id &id) {
            std::cout << "Aha! creating: " << id << std::endl;
            this->id = id;
        }

        logic_sym(const logic_sym &orig)=delete;

    private:
        logic_id id;
    };

Answer 1

You may not simply cast a void * pointer to a pointer to logic_sym. You must use a placement new operator to initialize the memory.

new(pointer) logic_sym(26)

However, why are you fussing with malloc and free instead of just using new and delete?`