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diff --git a/libs/ftl/small_vector_test.cpp b/libs/ftl/small_vector_test.cpp
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+++ b/libs/ftl/small_vector_test.cpp
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+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ftl/small_vector.h>
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <iterator>
+#include <string>
+#include <utility>
+
+using namespace std::string_literals;
+
+namespace android::test {
+
+using ftl::SmallVector;
+
+// Keep in sync with example usage in header file.
+TEST(SmallVector, Example) {
+  ftl::SmallVector<char, 3> vector;
+  EXPECT_TRUE(vector.empty());
+  EXPECT_FALSE(vector.dynamic());
+
+  vector = {'a', 'b', 'c'};
+  EXPECT_EQ(vector.size(), 3u);
+  EXPECT_FALSE(vector.dynamic());
+
+  vector.push_back('d');
+  EXPECT_TRUE(vector.dynamic());
+
+  vector.unstable_erase(vector.begin());
+  EXPECT_EQ(vector, (ftl::SmallVector{'d', 'b', 'c'}));
+
+  vector.pop_back();
+  EXPECT_EQ(vector.back(), 'b');
+  EXPECT_TRUE(vector.dynamic());
+
+  const char array[] = "hi";
+  vector = ftl::SmallVector(array);
+  EXPECT_EQ(vector, (ftl::SmallVector{'h', 'i', '\0'}));
+  EXPECT_FALSE(vector.dynamic());
+
+  ftl::SmallVector strings = ftl::init::list<std::string>("abc")("123456", 3u)(3u, '?');
+  ASSERT_EQ(strings.size(), 3u);
+  EXPECT_FALSE(strings.dynamic());
+
+  EXPECT_EQ(strings[0], "abc");
+  EXPECT_EQ(strings[1], "123");
+  EXPECT_EQ(strings[2], "???");
+}
+
+TEST(SmallVector, Construct) {
+  {
+    // Default constructor.
+    SmallVector<std::string, 2> vector;
+
+    EXPECT_TRUE(vector.empty());
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // Array constructor.
+    const float floats[] = {.1f, .2f, .3f};
+    SmallVector vector(floats);
+
+    EXPECT_EQ(vector, (SmallVector{.1f, .2f, .3f}));
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // Iterator constructor.
+    const char chars[] = "abcdef";
+    std::string string(chars);
+    SmallVector<char, sizeof(chars)> vector(string.begin(), string.end());
+
+    EXPECT_STREQ(vector.begin(), chars);
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // Variadic constructor with same types.
+    SmallVector vector = {1, 2, 3};
+
+    static_assert(std::is_same_v<decltype(vector), SmallVector<int, 3>>);
+    EXPECT_EQ(vector, (SmallVector{1, 2, 3}));
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // Variadic constructor with different types.
+    const auto copy = "quince"s;
+    auto move = "tart"s;
+    SmallVector vector = {copy, std::move(move)};
+
+    static_assert(std::is_same_v<decltype(vector), SmallVector<std::string, 2>>);
+    EXPECT_EQ(vector, (SmallVector{"quince"s, "tart"s}));
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // In-place constructor with same types.
+    SmallVector vector =
+        ftl::init::list<std::string>("redolent", 3u)("velveteen", 6u)("cakewalk", 4u);
+
+    static_assert(std::is_same_v<decltype(vector), SmallVector<std::string, 3>>);
+    EXPECT_EQ(vector, (SmallVector{"red"s, "velvet"s, "cake"s}));
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // In-place constructor with different types.
+    const auto copy = "red"s;
+    auto move = "velvet"s;
+    std::initializer_list<char> list = {'c', 'a', 'k', 'e'};
+    SmallVector vector = ftl::init::list<std::string>(copy.c_str())(std::move(move))(list);
+
+    static_assert(std::is_same_v<decltype(vector), SmallVector<std::string, 3>>);
+    EXPECT_TRUE(move.empty());
+    EXPECT_EQ(vector, (SmallVector{"red"s, "velvet"s, "cake"s}));
+    EXPECT_FALSE(vector.dynamic());
+  }
+  {
+    // Conversion from StaticVector.
+    ftl::StaticVector doubles = {.1, .2, .3};
+    SmallVector vector = std::move(doubles);
+    EXPECT_TRUE(doubles.empty());
+
+    static_assert(std::is_same_v<decltype(vector), SmallVector<double, 3>>);
+    EXPECT_EQ(vector, (SmallVector{.1, .2, .3}));
+    EXPECT_FALSE(vector.dynamic());
+  }
+}
+
+TEST(SmallVector, String) {
+  SmallVector<char, 10> chars;
+  char c = 'a';
+  std::generate_n(std::back_inserter(chars), chars.max_size(), [&c] { return c++; });
+  chars.push_back('\0');
+
+  EXPECT_TRUE(chars.dynamic());
+  EXPECT_EQ(chars.size(), 11u);
+  EXPECT_STREQ(chars.begin(), "abcdefghij");
+
+  // Constructor takes iterator range.
+  const char numbers[] = "123456";
+  SmallVector<char, 10> string(std::begin(numbers), std::end(numbers));
+
+  EXPECT_FALSE(string.dynamic());
+  EXPECT_STREQ(string.begin(), "123456");
+  EXPECT_EQ(string.size(), 7u);
+
+  // Similar to emplace, but replaces rather than inserts.
+  string.replace(string.begin() + 5, '\0');
+  EXPECT_STREQ(string.begin(), "12345");
+
+  swap(chars, string);
+
+  EXPECT_STREQ(chars.begin(), "12345");
+  EXPECT_STREQ(string.begin(), "abcdefghij");
+
+  EXPECT_FALSE(chars.dynamic());
+  EXPECT_TRUE(string.dynamic());
+}
+
+TEST(SmallVector, CopyableElement) {
+  struct Pair {
+    // Needed because std::vector does not use list initialization to emplace.
+    Pair(int a, int b) : a(a), b(b) {}
+
+    const int a, b;
+    bool operator==(Pair p) const { return p.a == a && p.b == b; }
+  };
+
+  SmallVector<Pair, 5> pairs;
+
+  EXPECT_TRUE(pairs.empty());
+  EXPECT_EQ(pairs.max_size(), 5u);
+
+  for (size_t i = 0; i < pairs.max_size(); ++i) {
+    EXPECT_EQ(pairs.size(), i);
+
+    const int a = static_cast<int>(i) * 2;
+    EXPECT_EQ(pairs.emplace_back(a, a + 1), Pair(a, a + 1));
+  }
+
+  EXPECT_EQ(pairs.size(), 5u);
+  EXPECT_FALSE(pairs.dynamic());
+
+  // The vector is promoted when full.
+  EXPECT_EQ(pairs.emplace_back(10, 11), Pair(10, 11));
+  EXPECT_TRUE(pairs.dynamic());
+
+  EXPECT_EQ(pairs, (SmallVector{Pair{0, 1}, Pair{2, 3}, Pair{4, 5}, Pair{6, 7}, Pair{8, 9},
+                                Pair{10, 11}}));
+
+  // Constructor takes at most N elements.
+  SmallVector<int, 6> sums = {0, 0, 0, 0, 0, 0};
+  EXPECT_FALSE(sums.dynamic());
+
+  // Random-access iterators comply with standard.
+  std::transform(pairs.begin(), pairs.end(), sums.begin(), [](Pair p) { return p.a + p.b; });
+  EXPECT_EQ(sums, (SmallVector{1, 5, 9, 13, 17, 21}));
+
+  sums.pop_back();
+  std::reverse(sums.begin(), sums.end());
+
+  EXPECT_EQ(sums, (SmallVector{17, 13, 9, 5, 1}));
+}
+
+TEST(SmallVector, MovableElement) {
+  // Construct std::string elements in place from per-element arguments.
+  SmallVector strings = ftl::init::list<std::string>()()()("cake")("velvet")("red")();
+  strings.pop_back();
+
+  EXPECT_EQ(strings.max_size(), 7u);
+  EXPECT_EQ(strings.size(), 6u);
+
+  // Erase "cake" and append a substring copy.
+  {
+    const auto it =
+        std::find_if(strings.begin(), strings.end(), [](const auto& s) { return !s.empty(); });
+    ASSERT_FALSE(it == strings.end());
+    EXPECT_EQ(*it, "cake");
+
+    // Construct std::string from first 4 characters of string literal.
+    strings.unstable_erase(it);
+    EXPECT_EQ(strings.emplace_back("cakewalk", 4u), "cake"s);
+  }
+
+  strings[1] = "quince"s;
+
+  // Replace last empty string with "tart".
+  {
+    const auto rit = std::find(strings.rbegin(), strings.rend(), std::string());
+    ASSERT_FALSE(rit == strings.rend());
+
+    std::initializer_list<char> list = {'t', 'a', 'r', 't'};
+    strings.replace(rit.base() - 1, list);
+  }
+
+  strings.front().assign("pie");
+
+  EXPECT_EQ(strings, (SmallVector{"pie"s, "quince"s, "tart"s, "red"s, "velvet"s, "cake"s}));
+
+  strings.push_back("nougat");
+  strings.push_back("oreo");
+  EXPECT_TRUE(strings.dynamic());
+
+  std::rotate(strings.begin(), strings.end() - 2, strings.end());
+
+  EXPECT_EQ(strings, (SmallVector{"nougat"s, "oreo"s, "pie"s, "quince"s, "tart"s, "red"s, "velvet"s,
+                                  "cake"s}));
+}
+
+TEST(SmallVector, Replace) {
+  // Replacing does not require a copy/move assignment operator.
+  struct Word {
+    explicit Word(std::string str) : str(std::move(str)) {}
+    const std::string str;
+
+    bool operator==(const Word& other) const { return other.str == str; }
+  };
+
+  SmallVector words = ftl::init::list<Word>("colored")("velour");
+
+  // The replaced element can be referenced by the replacement.
+  {
+    const Word& word = words.replace(words.last(), words.back().str.substr(0, 3) + "vet");
+    EXPECT_EQ(word, Word("velvet"));
+  }
+
+  // The vector is not promoted if replacing while full.
+  EXPECT_FALSE(words.dynamic());
+
+  words.emplace_back("cake");
+  EXPECT_TRUE(words.dynamic());
+
+  {
+    const Word& word = words.replace(words.begin(), words.front().str.substr(4));
+    EXPECT_EQ(word, Word("red"));
+  }
+
+  EXPECT_EQ(words, (SmallVector{Word("red"), Word("velvet"), Word("cake")}));
+}
+
+TEST(SmallVector, ReverseAppend) {
+  SmallVector strings = {"red"s, "velvet"s, "cake"s};
+  EXPECT_FALSE(strings.dynamic());
+
+  auto rit = strings.rbegin();
+  while (rit != strings.rend()) {
+    // Iterator and reference are invalidated on insertion.
+    const auto i = std::distance(strings.begin(), rit.base());
+    std::string s = *rit;
+
+    strings.push_back(std::move(s));
+    rit = std::make_reverse_iterator(strings.begin() + i) + 1;
+  }
+
+  EXPECT_EQ(strings, (SmallVector{"red"s, "velvet"s, "cake"s, "cake"s, "velvet"s, "red"s}));
+  EXPECT_TRUE(strings.dynamic());
+}
+
+TEST(SmallVector, Sort) {
+  SmallVector strings = ftl::init::list<std::string>("pie")("quince")("tart")("red")("velvet");
+  strings.push_back("cake"s);
+
+  auto sorted = std::move(strings);
+  EXPECT_TRUE(strings.empty());
+
+  EXPECT_TRUE(sorted.dynamic());
+  EXPECT_TRUE(strings.dynamic());
+
+  std::sort(sorted.begin(), sorted.end());
+  EXPECT_EQ(sorted, (SmallVector{"cake"s, "pie"s, "quince"s, "red"s, "tart"s, "velvet"s}));
+
+  // Constructor takes array reference.
+  {
+    const char* array[] = {"cake", "lie"};
+    strings = SmallVector(array);
+    EXPECT_FALSE(strings.dynamic());
+  }
+
+  EXPECT_GT(sorted, strings);
+  swap(sorted, strings);
+  EXPECT_LT(sorted, strings);
+
+  EXPECT_FALSE(sorted.dynamic());
+  EXPECT_TRUE(strings.dynamic());
+
+  // Append remaining elements, such that "pie" is the only difference.
+  for (const char* str : {"quince", "red", "tart", "velvet"}) {
+    sorted.emplace_back(str);
+  }
+  EXPECT_TRUE(sorted.dynamic());
+
+  EXPECT_NE(sorted, strings);
+
+  // Replace second element with "pie".
+  const auto it = sorted.begin() + 1;
+  EXPECT_EQ(sorted.replace(it, 'p' + it->substr(1)), "pie");
+
+  EXPECT_EQ(sorted, strings);
+}
+
+namespace {
+
+struct DestroyCounts {
+  DestroyCounts(int& live, int& dead) : counts{live, dead} {}
+  DestroyCounts(const DestroyCounts& other) : counts(other.counts) {}
+  DestroyCounts(DestroyCounts&& other) : counts(other.counts) { other.alive = false; }
+  ~DestroyCounts() { ++(alive ? counts.live : counts.dead); }
+
+  struct {
+    int& live;
+    int& dead;
+  } counts;
+
+  bool alive = true;
+};
+
+void swap(DestroyCounts& lhs, DestroyCounts& rhs) {
+  std::swap(lhs.alive, rhs.alive);
+}
+
+}  // namespace
+
+TEST(SmallVector, Destroy) {
+  int live = 0;
+  int dead = 0;
+
+  { SmallVector<DestroyCounts, 3> counts; }
+  EXPECT_EQ(0, live);
+  EXPECT_EQ(0, dead);
+
+  {
+    SmallVector<DestroyCounts, 3> counts;
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+
+    EXPECT_FALSE(counts.dynamic());
+  }
+  EXPECT_EQ(3, live);
+  EXPECT_EQ(0, dead);
+
+  live = 0;
+  {
+    SmallVector<DestroyCounts, 3> counts;
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+
+    EXPECT_TRUE(counts.dynamic());
+  }
+  EXPECT_EQ(4, live);
+  EXPECT_EQ(3, dead);
+
+  live = dead = 0;
+  {
+    SmallVector<DestroyCounts, 2> counts;
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+
+    auto copy = counts;
+    EXPECT_TRUE(copy.dynamic());
+  }
+  EXPECT_EQ(6, live);
+  EXPECT_EQ(2, dead);
+
+  live = dead = 0;
+  {
+    SmallVector<DestroyCounts, 2> counts;
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+    counts.emplace_back(live, dead);
+
+    auto move = std::move(counts);
+    EXPECT_TRUE(move.dynamic());
+  }
+  EXPECT_EQ(3, live);
+  EXPECT_EQ(2, dead);
+
+  live = dead = 0;
+  {
+    SmallVector<DestroyCounts, 2> counts1;
+    counts1.emplace_back(live, dead);
+    counts1.emplace_back(live, dead);
+    counts1.emplace_back(live, dead);
+
+    EXPECT_TRUE(counts1.dynamic());
+    EXPECT_EQ(2, dead);
+    dead = 0;
+
+    SmallVector<DestroyCounts, 2> counts2;
+    counts2.emplace_back(live, dead);
+
+    EXPECT_FALSE(counts2.dynamic());
+
+    swap(counts1, counts2);
+
+    EXPECT_FALSE(counts1.dynamic());
+    EXPECT_TRUE(counts2.dynamic());
+
+    EXPECT_EQ(0, live);
+    EXPECT_EQ(1, dead);
+
+    dead = 0;
+  }
+  EXPECT_EQ(4, live);
+  EXPECT_EQ(0, dead);
+}
+
+}  // namespace android::test