how to tell auto to deduct a non reference type for element of vector

Here is the code:

int main()
{
    std::vector<bool> b(5,false);
    auto b0=b[0];
    cout<<b0;
    b[0]=true;
    cout<<b0;
    std::vector<int> i(5,false);
    auto i0=i[0];
    cout<<i0;
    i[0]=true;
    cout<<i0;

    return 0;
}

0100

The variable b0 is with reference type (std::_Bit_reference) while i0 is normal int. What is the right grammar to tell auto to deduce some non reference type, for example, bool?