}
		pre = cur
	}
	return true
}

// alignSparseEntries mutates src and returns dst where each fragment's
// starting offset is aligned up to the nearest block edge, and each
// ending offset is aligned down to the nearest block edge.
//
// Even though the Go tar Reader and the BSD tar utility can handle entries
// with arbitrary offsets and lengths, the GNU tar utility can only handle

	}
	show("Gopher", "Go")
	show("Gopher", "ph")
	show("Gopher", "er")
	show("Gopher", "Badger")
	// Output:
	// Cut("Gopher", "Go") = "", "pher", true
	// Cut("Gopher", "ph") = "Go", "er", true
	// Cut("Gopher", "er") = "Goph", "", true
	// Cut("Gopher", "Badger") = "Gopher", "", false
}

func ExampleCutPrefix() {
	show := func(s, sep string) {

would never access <code>*p</code> or <code>*q</code>, but the rewritten program would.
And if the call contained synchronizing operations, then the original program
could establish happens before edges preceding the accesses
to <code>*p</code> and <code>*q</code>, but the rewritten program would not.
</p>

<p>
Not allowing a single read to observe multiple values means