function type with ternary operator

I try this code:

    int a=1;
    std::function<int (int, int)> getM = a?
    [](int x, int y) {
        return (x+y);
    } :
    [](int x, int y) {
        return (x*y);
    };


    cout<<getM(1,2);

In visual studio it gives an error: error C2446: ':' : no conversion from 'wmain::' to 'wmain::' 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called

In GCC it's compiled. I suppose that GCC is the correct behaviour, but I'm not sure. What are other options to make this on VS2013?