Although it seems the snappers return the necessary displacement, and not the point to which they snapped.
 I propose to make the snappers return something like a SnapInfo struct:

struct SnapInfo {
	bool snapped;  //did we snap?
	Geom::Point snaplocation; // to which point did we snap
	SnapType type;  // some info about the sort of snap (tangential, node-on-node, whatever, this is future work of course)
	...
} 

I do have a bugreport though: guides don't snap! the guideSnap function never gets past the check if it should snap at all, so it always returns Inkscape::SnappedPoint(p, NR_HUGE, 0, false). Can you look into this Diederik? Once guide snapping works, you'll see the snapindicator on-canvas :)

On Jan 13, 2008 3:39 PM, Diederik van Lierop <mail@...1689...> wrote:

This has been explained by Max and Gez, so I guess that has been cleared
up. BTW, what has changed recently is that only the part of the guide
near the cursor now snaps, not the full length of the guide.

Well, I just tried, and for me guideline does not snap to a rect,
after i ticked "snap guides while dragging" and both snap to paths and
snap to nodes. And dragging it with mouse over the rect. What am I
doing wrong?