c++ : Universal getter for class

I kind of need help! I want to define a template method for my class to access its private fields. Here is my code:

#include <string>
#include <vector>
using namespace std;

class ex
{
public:
    ex(string pegah_,int amin_):pegah(pegah_),amin(amin_){}
    template<typename T>
    T get_field(){
        if(is_same<T,string>::value)
            return pegah;
        else if(is_same<T,int> ::value)
            return amin;
    }
private:
    string pegah;
    int amin;
};

int main(void)
{
    string i = "salam";
    int o=10;
    ex y(i,o);
    y.get_field<string>();
}

as you see I want to use just one function. But I keep getting this error:

test.cpp: In instantiation of ‘T ex::get_field() [with T = std::basic_string<char>]’:
test.cpp:30:21:   required from here
test.cpp:15:8: error: invalid conversion from ‘int’ to ‘const char*’ [-fpermissive]
 return amin;
        ^
In file included from /usr/include/c++/4.8/string:52:0,
                 from test.cpp:1:
/usr/include/c++/4.8/bits/basic_string.h:490:7: error:   initializing argument 1 of ‘std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’ [-fpermissive]
       basic_string(const _CharT* __s, const _Alloc& __a = _Alloc());

can anyone help?