karam hello <karamhello2@gmail.com> writes:

> i have a problem with this program using C++ OOP inheritance
> specially on class c:

Your compiler should be telling your what's wrong. It might not do so
very clearly, but it should be pointing you to where the problem is.

But let me play compiler here and give you a different error message...

> #include <iostream>
> using namespace std;
> class a{
> private:
> string name;
> int age;
> public:
> a(string n, int a){
> name = n;
> age = a;
> }
> };
> class b{
> private:
> string email;
> public:
> b(string em){
> email = em;
> }
> };
> class c:public a, public b{
> public:
> c(string n, int a, string em) : a(n, a), b(em){}
line 23 position 41 ______________________^
a is an int. I can't call a(n, a) when a is an int.

> };
> int main(){
> c c1("k", 10, "com");
> }

Does that help?

--
Ben.

On 2023-09-29 10:13 PM, Ben Bacarisse wrote:
> karam hello <karamhello2@gmail.com> writes:
>
>> i have a problem with this program using C++ OOP inheritance
>> specially on class c:
>
> Your compiler should be telling your what's wrong. It might not do so
> very clearly, but it should be pointing you to where the problem is.
>
> But let me play compiler here and give you a different error message...
>
>> #include <iostream>
>> using namespace std;
>> class a{
>> private:
>> string name;
>> int age;
>> public:
>> a(string n, int a){
>> name = n;
>> age = a;
>> }
>> };
>> class b{
>> private:
>> string email;
>> public:
>> b(string em){
>> email = em;
>> }
>> };
>> class c:public a, public b{
>> public:
>> c(string n, int a, string em) : a(n, a), b(em){}
> line 23 position 41 ______________________^
> a is an int. I can't call a(n, a) when a is an int.
>
>> };
>> int main(){
>> c c1("k", 10, "com");
>> }
>
> Does that help?

g++ complains about that thing, but Visual C++ compiles the code just
fine as C++17.

Sort of, Visual C++ is consistent (base classes treated the same as data
members), while g++ is conforming. They're both "con". Just differently.

I guess learning point is, to be both consistent and conforming never
choose the same name for a constructor parameter and sub-object.

- Alf

"Alf P. Steinbach" <alf.p.steinbach@gmail.com> writes:

> On 2023-09-29 10:13 PM, Ben Bacarisse wrote:
>> karam hello <karamhello2@gmail.com> writes:
>>
>>> i have a problem with this program using C++ OOP inheritance
>>> specially on class c:
>> Your compiler should be telling your what's wrong. It might not do so
>> very clearly, but it should be pointing you to where the problem is.
>> But let me play compiler here and give you a different error message...
>>
>>> #include <iostream>
>>> using namespace std;
>>> class a{
>>> private:
>>> string name;
>>> int age;
>>> public:
>>> a(string n, int a){
>>> name = n;
>>> age = a;
>>> }
>>> };
>>> class b{
>>> private:
>>> string email;
>>> public:
>>> b(string em){
>>> email = em;
>>> }
>>> };
>>> class c:public a, public b{
>>> public:
>>> c(string n, int a, string em) : a(n, a), b(em){}
>> line 23 position 41 ______________________^
>> a is an int. I can't call a(n, a) when a is an int.
>>
>>> };
>>> int main(){
>>> c c1("k", 10, "com");
>>> }
>> Does that help?
>
> g++ complains about that thing, but Visual C++ compiles the code just fine
> as C++17.

Curious. Which one is correct? Without studying the standard, I would
have thought that gcc has it right.

--
Ben.

"Alf P. Steinbach" <alf.p.steinbach@gmail.com> writes:

> On 2023-09-29 10:13 PM, Ben Bacarisse wrote:
>> karam hello <karamhello2@gmail.com> writes:
>>
>>> i have a problem with this program using C++ OOP inheritance
>>> specially on class c:
>> Your compiler should be telling your what's wrong. It might not do so
>> very clearly, but it should be pointing you to where the problem is.
>> But let me play compiler here and give you a different error message...
>>
>>> #include <iostream>
>>> using namespace std;
>>> class a{
>>> private:
>>> string name;
>>> int age;
>>> public:
>>> a(string n, int a){
>>> name = n;
>>> age = a;
>>> }
>>> };
>>> class b{
>>> private:
>>> string email;
>>> public:
>>> b(string em){
>>> email = em;
>>> }
>>> };
>>> class c:public a, public b{
>>> public:
>>> c(string n, int a, string em) : a(n, a), b(em){}
>> line 23 position 41 ______________________^
>> a is an int. I can't call a(n, a) when a is an int.
>>
>>> };
>>> int main(){
>>> c c1("k", 10, "com");
>>> }
>> Does that help?
>
> g++ complains about that thing, but Visual C++ compiles the code just fine
> as C++17.

Curious. Which one is correct I wonder.

--
Ben.