diff --git a/src/simulation.cpp b/src/simulation.cpp
index b077d0f..832af83 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -43,6 +43,10 @@ CellIterator::CellIterator(Cell begin, Cell end)
 CellIterator::CellIterator(Cell begin, Cell end, Cell state)
 : state{ state } , begin{ begin }, end{ end } {}
 
+static inline bool CellIsAlive(Cell const &cell) {
+	return living.contains(cell);
+}
+
 CellIterator &CellIterator::operator++() {
 	++(this->state.x);
 	if (this->state.x == this->end.x) {
@@ -71,7 +75,7 @@ bool CellIterator::at_end() const {
 static size_t CountNeighbors(Cell const &cell) {
 	size_t count{ 0 };
 	for (Cell const &c : CellRange{ {cell.x - 1, cell.y - 1}, { cell.x + 2, cell.y + 2} }) {
-		if (c != cell && living.contains(c)) {
+		if (c != cell && CellIsAlive(c)) {
 			++count;
 		}
 	}
@@ -147,7 +151,7 @@ static void FindBorn(std::shared_ptr<ThreadWorkload> wl) {
 		CellRange range{{ center.x - 1, center.y - 1 }, {center.x + 2, center.y + 2 }};
 		std::copy_if(range.begin(), range.end(), std::back_inserter(wl->changes),
 		[&](Cell const &c) -> bool {
-			return !living.contains(c) && CountNeighbors(c) == 3;
+			return !CellIsAlive(c) && CountNeighbors(c) == 3;
 		});
 	});
 	TaskComplete();