cmp/report_reflect.go
func (m visitedPointers) Visit(v reflect.Value) bool {
	p := value.PointerOf(v)
	_, visited := m[p]
	m[p] = struct{}{}
	return visited
}
func (m visitedPointers) Visit(v reflect.Value) bool {
	p := value.PointerOf(v)
	_, visited := m[p]
	m[p] = struct{}{}
	return visited
}
func ( m visitedPointers ) Visit ( v reflect . Value ) bool { p := value . PointerOf ( v ) _ , visited := m [ p ] m [ p ] = struct { } { } return visited }
// Visit inserts pointer v into the visited map and reports whether it had
// already been visited before.
Visit inserts pointer v into the visited map and reports whether it had already been visited before .