Re: Error when returning a structure pointer

From:
"Thomas Tutone" <Thomas8675309@yahoo.com>
Newsgroups:
comp.lang.c++.moderated
Date:
29 Jun 2006 05:03:29 -0400
Message-ID:
<1151506224.918489.111020@j72g2000cwa.googlegroups.com>
pai wrote:

  The following program gives error can any one solve this.

#include<iostream.h>


Please substitute the following for the above line:
#include <iostream>
using std::cout;

struct ab{
        int a;
};

template <class T>
class A{

                struct ab * ret_1();


Why do you use "struct" in the above line? It confuses matters. Please
omit it. In other words, substitute the following instead:

                    ab* ret_1();

        public:
                A();
                void disp();
                void ret();


Please note that in the above line, you declare ret() to return void.

};

template <class T>
void A<T>::ret(){


Again, please note that you have declared this member function to
return void, not ab*.

        struct ab* b;


Again, why do you use "struct" in the above line? It confuses matters.
Please omit it.

        b=ret_1();

        return b;


The above line is an error. This function returns void, not ab*, so
please delete the above line entirely.

}

template <class T>
struct ab * A<T>::ret_1(){


Again, why do you use "struct" in the above line? It confuses matters.
Please omit it.

        struct ab* b;


Again, why do you use "struct" in the above line? It confuses matters.
Please omit it.

        b=new (struct ab);


Again, why do you use "struct" in the above line? It confuses matters.
Please omit it.

        return b;
}

template<class T>
A<T>::A(){

        cout << "A const" ;

}

template <class T>
void A<T>::disp(){
        cout << "disp" << endl;
}

int main(){

        A<int> a;

        a.disp();

        return 0;

}


[compilation errors snipped.]

This is just a sample program . I am trying to return a structure
pointer in a priviate method . but as the calss is template class
defining it is giveing me error . How could i rewite to remove the
error.


First, please don't use <iostream.h>, which is not a standard header.
Use <iostream> instead.

Second, if you have a void function, please don't try to return a value
- that's an error. When I fixed that (and the wrong header), your
program compiled fine (even if I didn't delete your unnecessary
"struct"s).

Third, although they don't actually affect the meaning, please omit all
the unnecessary "struct"s - they confuse matters (and appear to confuse
your compiler as well).

Best regards,

Tom

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