Frederic, there isn't a built in "snap to" function, but here is work around. Let's say you have two locators on two video clipe (V1 and V2). Trim the V2 clip to the locator. While trimming if you hold the Command key (CTRL) your cursor will snap to the closest edit or locator.
Then move your position bar to the locator on V1, and drag V2. Again, while holding CMD, the clip will snap to the position bar. Then move the trim back out for V2.
Hope that helps.
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