Div centering: when width auto

.outermost-div{
    overflow:hidden;  
}


.inner-div{
   float:left;
    left:50%;
    position: relative;
}

.centered-div{
    position: relative;
    float:left;
    left: -50% ;
    width: auto;
}

<div class = "outermost-div"> <div class = "inner-div"> <div class = "centered-div"> Example </div> </div> </div>