Error with typedef inside a class...

[gpraghuram]

I wrote the following code

#include <map>
#include<iostream>
using namespace std;
 
//typedef map<int,int> Maps;
 
class A
{
public:
                typedef map<int,int> Maps;
 
    private:
        Maps *m_MapP;
    public:
        Maps* getMapP();
        int* getIntP();
};
 
Maps* A::getMapP()
{
    return m_MapP;
}
 
int* A::getIntP()
{
    return NULL;
}
 
 
int main()
{
    return 0;
}
 

When i compile this i am getting compiler error in the method definition of getMapP.
But when i move the typedf declaration above the class then it is working fine.
I cant figure out why this is happeneing.
can somebody comment on this.

Thanks
Raghuram

[Joby Allen]

I wrote the following code

#include <map>
#include<iostream>
using namespace std;
 
//typedef map<int,int> Maps;
 
class A
{
public:
                typedef map<int,int> Maps;
 
    private:
        Maps *m_MapP;
    public:
        Maps* getMapP();
        int* getIntP();
};
 
Maps* A::getMapP()
{
    return m_MapP;
}
 
int* A::getIntP()
{
    return NULL;
}
 
 
int main()
{
    return 0;
}
 

When i compile this i am getting compiler error in the method definition of getMapP.
But when i move the typedf declaration above the class then it is working fine.
I cant figure out why this is happeneing.
can somebody comment on this.

Because the Maps typedef is inside your class, you need to scope it accordingly.

A::Maps* A::getMapP()
 

should do the trick.

Regards,

-Joby

[gpraghuram]

Because the Maps typedef is inside your class, you need to scope it accordingly.

A::Maps* A::getMapP()
 

should do the trick.

Regards,

-Joby

What u say is right.
But why we have to specify the scope resolution for the return type alone.
But for argument you need not specify this.
Check this code

A::Maps* A::getMapP()
{
}
A::Maps* A::getMapP(Maps *p)//This works fine without A:: 
 

My doubt is what is C++ syntax for this typedef,,,that is what my question is.


Raghuram

[Joby Allen]

What u say is right.
But why we have to specify the scope resolution for the return type alone.
But for argument you need not specify this.
Check this code

A::Maps* A::getMapP()
{
}
A::Maps* A::getMapP(Maps *p)//This works fine without A:: 
 

My doubt is what is C++ syntax for this typedef,,,that is what my question is.


Raghuram

Interesting. My guess here is that the default scope of the arguments of a method are the same as the scope of the method itself. In other words, the compiler checks A:: for a definition of Maps before checking globally.

As I said, this is just a guess, maybe a browse through Stroustrup will explain this definitively.

[gpraghuram]

What i thought is
The typedef gets resolved only inside the class method and the class method signature.
As return type is not part of signature , i think this is not getting resolved.

Other experts please correct me if i am wrong

Raghuram