Problem while using anonymous union in C++

[SRK]

Hi,
I wanted to use an anonymous union within an structure something like
below -

struct Test
{
union
{
std::string user; //char user[50];
std::string role; //char role[50];
};
std::string desc;
};

Whenever I use, built in data types such as int, char etc, it works
perfectly fine, but for user defined dataypes, it gives me error -

error: member `std::string Test::<anonymou s union>::user' with
constructor not allowed in union
error: member `std::string Test::<anonymou s union>::user' with
destructor not allowed in union
error: member `std::string Test::<anonymou s union>::user' with copy
assignment operator not allowed in union
error: member `std::string Test::<anonymou s union>::role' with
constructor not allowed in union
error: member `std::string Test::<anonymou s union>::role' with
destructor not allowed in union
error: member `std::string Test::<anonymou s union>::role' with copy
assignment operator not allowed in union

Can someone give any idea, how to sort out the problem?

Thanks in advance.

- Shiv Ranjan
kumarsr@gmail.c om

[anon]

Re: Problem while using anonymous union in C++

SRK wrote:

Hi,
I wanted to use an anonymous union within an structure something like
below -
>
struct Test
{
union
{
std::string user; //char user[50];
std::string role; //char role[50];
};
std::string desc;
};

This is not allowed (using std::string in a union)

>
Whenever I use, built in data types such as int, char etc, it works
perfectly fine, but for user defined dataypes, it gives me error -
>
error: member `std::string Test::<anonymou s union>::user' with
constructor not allowed in union
error: member `std::string Test::<anonymou s union>::user' with
destructor not allowed in union
error: member `std::string Test::<anonymou s union>::user' with copy
assignment operator not allowed in union
error: member `std::string Test::<anonymou s union>::role' with
constructor not allowed in union
error: member `std::string Test::<anonymou s union>::role' with
destructor not allowed in union
error: member `std::string Test::<anonymou s union>::role' with copy
assignment operator not allowed in union
>
Can someone give any idea, how to sort out the problem?
>

Listen what your compiler is telling you

[SRK]

Re: Problem while using anonymous union in C++

On Oct 21, 3:06 pm, anon <a...@no.invali dwrote:

SRK wrote:

Hi,
I wanted to use an anonymous union within an structure something like
below -

>

struct Test
{
    union
    {
        std::string user; //char user[50];
        std::string role;  //char role[50];
    };
    std::string desc;
};

>
This is not allowed (using std::string in a union)
>
>
>
>
>

Whenever I use, built in data types such as int, char etc, it works
perfectly fine, but for user defined dataypes, it gives me error -

>

error: member `std::string Test::<anonymou s union>::user' with
constructor not allowed in union
error: member `std::string Test::<anonymou s union>::user' with
destructor not allowed in union
error: member `std::string Test::<anonymou s union>::user' with copy
assignment operator not allowed in union
error: member `std::string Test::<anonymou s union>::role' with
constructor not allowed in union
error: member `std::string Test::<anonymou s union>::role' with
destructor not allowed in union
error: member `std::string Test::<anonymou s union>::role' with copy
assignment operator not allowed in union

>

Can someone give any idea, how to sort out the problem?

>
Listen what your compiler is telling you

I understand what the compiler is saying and thats why I wanted
whether there is any workaround for that or not?

- Shiv

[dertopper@web.de]

Re: Problem while using anonymous union in C++

SRK wrote:

Hi,
I wanted to use an anonymous union within an structure something like
below -

>

struct Test
{
    union
    {
        std::string user; //char user[50];
        std::string role;  //char role[50];
    };
    std::string desc;
};

>

This is not allowed (using std::string in a union)

>

Whenever I use, built in data types such as int, char etc, it works
perfectly fine, but for user defined dataypes, it gives me error -

>

[snipped error messages]

>

Can someone give any idea, how to sort out the problem?

>

Listen what your compiler is telling you

>
I understand what the compiler is saying and thats why I wanted
whether there is any workaround for that or not?

There's no workaround for this. Why don't you use the following:

class Test
{
private:
std::string user_or_role;
public:
std::string& get_user ()
{
return user_or_role;
}

std::string& get_role ()
{
return user_or_role;
}
std::string desc;
};

Regards,
Stuart