C++ 没有可行的构造函数复制类型的变量

Question

I am getting the following error message:

main.cpp: No viable constructor copying variable of type 'communal'

On the second constructor, communal( const T& instance ) , the following message is given:

data.h: Candidate constructor not viable: no known conversion from 'communal' to 'const int &' for 1st argument

The conversion appears to be going backwards. I want the conversion to go from const int& to communal. Is there a way to get implicit conversion to work here? Thanks for any help.

main.cpp:

communal<int> test_communal1 = 123; // Implicit initialization triggers error

data.cpp:

template<typename T>
struct communal : general_type::communal<T>
{
    using super = general_type::communal<T>;

    communal() : super( nullptr ) {}
    communal( const T& instance ) : super( new T( instance ) ) {}
    communal( const T* instance ) : super( new T( instance ) ) {}
    communal( communal<T>& instance ) : super( instance ) {}
    communal( communal<T>* instance ) : super( instance ) {}

    ~communal()
    {
        this->counter->deallocate( [this]()
        {
            delete this->counter;
            delete this->instance;
        });
    }
};

Answer 1

I figured out the solution to this. My intention was to get the following converting constructor to work communal( const T& instance ) . I made the mistake of leaving off const for my copy constructors. For some reason, it was deducing to use the faulty copy constructor along with potential conversion from communal<int> to const int& . In adding const to the constructor, it fixed the problem. Though, it does seem to be a bug that it would not prioritize using the converting constructor first. Maybe with more studying this problem, I could get a deeper understanding to why it prioritized the other constructor over the converting constructor. Though, that will have to wait for now.