Add FixedVector::back()

Author: danngreen

tests/fixed_vector_tests.cc

@@ -65,11 +65,29 @@ TEST_CASE("Iterator Erase different parts of vector") {
 	}
 }
 
-TEST_CASE("Constructor  inits back_idx variable") {
+TEST_CASE("Constructor inits size") {
 	FixedVector<int, 8> a{1, 3, 5};
 	CHECK(a.size() == 3);
 }
 
+TEST_CASE("back() returns default-constructed T with empty vector") {
+	struct T {
+		int x = 99999;
+	};
+	FixedVector<T, 3> a{T{.x = 1}, T{.x = 3}, T{.x = 5}};
+	CHECK(a.back().x == 5);
+	CHECK(a.pop_back().x == 5);
+
+	CHECK(a.back().x == 3);
+	CHECK(a.pop_back().x == 3);
+
+	CHECK(a.back().x == 1);
+	CHECK(a.pop_back().x == 1);
+
+	CHECK(a.back().x == 99999);
+	CHECK(a.pop_back().x == 99999);
+}
+
 TEST_CASE("Basic usage: operator[] reads") {
 	FixedVector<int, 4> a{1, 2, 3, 4};
 	CHECK(a[0] == 1);

util/fixed_vector.hh

@@ -26,6 +26,13 @@ public:
 		return data[idx];
 	}
 
+	T back() const {
+		if (back_idx > 0)
+			return data[back_idx - 1];
+		else
+			return T{};
+	}
+
 	bool push_back(T el) {
 		if (back_idx >= MaxElements)
 			return false;