c++11: Is there a way to write a polymorphic template function?

Lets say I have a function

template <typename T>
T foo() {
    // do stuff  
    return T(/* some value*/);
}

so I could call it for example like this:

int my_int = foo<int>();
std::string my_string = foo<std::string>();

Is there any way for me to create 2 separate polymorphic functions such that I could have a function that only gets called if T is std::string?

I tried doing this using the following code:

template <typename T>
T foo() {
    if (std::is_same<std::string, T>::value) {
       // do string specific stuff

    }

    return T(/* some value */);
}

but I would get compilation errors as the operations I wanted to do when T was std::string did not work when T was other types. Is there any way to make this polymorphic or should I just use a different function name like fooString()?