TinyVector resize method, and some tests

include/Containers/TinyVector.hpp

@@ -72,6 +72,10 @@ template <class T, size_t N, typename L = ptrdiff_t> class TinyVector {
     invariant(len > 0);
     --len;
   }
+  constexpr auto pop_back_val() -> T {
+    invariant(len > 0);
+    return std::move(data.data()[--len]);
+  }
   [[nodiscard]] constexpr auto size() const -> ptrdiff_t {
     ptrdiff_t l = ptrdiff_t(len);
     invariant(l >= 0);
@@ -85,5 +89,10 @@ template <class T, size_t N, typename L = ptrdiff_t> class TinyVector {
   constexpr auto begin() const -> const T * { return data.data(); }
   constexpr auto end() -> T * { return data.data() + size(); }
   constexpr auto end() const -> const T * { return data.data() + size(); }
+  constexpr void resize(L new_size) {
+    // initialize new data
+    for (L i = len; i < new_size; ++i) data.data()[i] = T{};
+    len = new_size;
+  }
 };
 } // namespace poly::containers

test/matrix_test.cpp

@@ -1,4 +1,5 @@
 #include "Alloc/Arena.hpp"
+#include "Containers/TinyVector.hpp"
 #include "Math/Array.hpp"
 #include "Math/Math.hpp"
 #include "Math/MatrixDimensions.hpp"
@@ -310,3 +311,38 @@ TEST(SVectorTest, BasicAssertions) {
   EXPECT_EQ(b, 22);
   EXPECT_EQ(c, 33);
 }
+TEST(TinyVectorTest, BasicAssertions) {
+  poly::containers::TinyVector<int, 5> v{};
+  EXPECT_TRUE(v.empty());
+  EXPECT_EQ(v.size(), 0);
+  v.resize(3);
+  EXPECT_FALSE(v.empty());
+  EXPECT_EQ(v.size(), 3);
+  EXPECT_EQ(v.back(), 0);
+  v.push_back(2);
+  EXPECT_EQ(v.size(), 4);
+  EXPECT_EQ(v.back(), 2);
+  EXPECT_EQ(v.pop_back_val(), 2);
+  EXPECT_EQ(v.front(), 0);
+  EXPECT_EQ(v.back(), 0);
+  EXPECT_EQ(v.size(), 3);
+  v.pop_back();
+  EXPECT_EQ(v.size(), 2);
+  v.pop_back();
+  EXPECT_FALSE(v.empty());
+  EXPECT_EQ(v.size(), 1);
+  v.pop_back();
+  EXPECT_TRUE(v.empty());
+  EXPECT_EQ(v.size(), 0);
+  v.push_back(5);
+  EXPECT_EQ(v.front(), 5);
+  EXPECT_EQ(v.back(), 5);
+  v.push_back(2);
+  EXPECT_EQ(v.front(), 5);
+  EXPECT_EQ(v.back(), 2);
+  v.push_back(21);
+  EXPECT_EQ(v.back(), 21);
+  int s = 0;
+  for (auto x : v) s += x;
+  EXPECT_EQ(s, 28);
+}