Making a flex item float right

I have a

<div class="parent">
    <div class="child" style="float:right"> Ignore parent? </div>
    <div> another child </div>
</div>

The parent has

.parent {
    display: flex;
}

For my first child, I want to simply float the item to the right.

And my other divs to follow the flex rule set by the parent.

Is this something possible?

If not, how do I do a float: right under flex?