I have a complex part, but this example should suffice.
Imagine you want to fit a round peg in a square hole, by deforming the square hole to be round. The easiest thing to do would be to insert a cylinder into the square hole and deform it by radially expanding to a specified distance using the cylinder as the tool.
Is there a way to do this?
Note: "curve to curve" using a circle would work if the part wasn't so complicated and has nonuniform edges.