Inline assembly inside C++ for data conversion

I am trying to write a C++ code for conversion of assembly dq 3FA999999999999Ah into C++ double. What to type inside asm block? I dont know how to take out the value.

int main()
{
    double x;

    asm
    {
        dq  3FA999999999999Ah
        mov x,?????
    }

    std::cout<<x<<std::endl;

    return 0;
}