  We study the boundary traces of Newton-Sobolev, Hajlasz-Sobolev, and BV
(bounded variation) functions. Assuming less regularity of the domain than is
usually done in the literature, we show that all of these function classes
achieve the same "boundary values", which in particular implies that the trace
spaces coincide provided that they exist. Many of our results seem to be new
even in Euclidean spaces but we work in a more general complete metric space
equipped with a doubling measure and supporting a Poincare inequality.
