diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -70,6 +70,14 @@
     arg_list.h
 )
 
+add_header_library(
+  arraystore
+  HDRS
+    arraystore.h
+  DEPENDS
+    libc.src.__support.CPP.array
+)
+
 add_subdirectory(FPUtil)
 add_subdirectory(OSUtil)
 
diff --git a/libc/src/__support/arraystore.h b/libc/src/__support/arraystore.h
new file mode 100644
--- /dev/null
+++ b/libc/src/__support/arraystore.h
@@ -0,0 +1,49 @@
+//===-- A data structure for a fixed size data store ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/CPP/array.h"
+
+namespace __llvm_libc {
+
+// A fixed size data store backed by an underlying cpp::array data structure. It
+// supports vector like API but is not resizable like a vector.
+template <typename T, size_t SIZE> class ArrayStore {
+  cpp::array<T, SIZE> store;
+  size_t item_count = 0;
+
+public:
+  constexpr ArrayStore() = default;
+
+  bool push_back(const T &obj) {
+    if (item_count == SIZE)
+      return false;
+    store[item_count] = obj;
+    ++item_count;
+    return true;
+  }
+
+  const T &back() const { return store[item_count - 1]; }
+
+  T &back() { return store[item_count - 1]; }
+
+  bool pop_back() {
+    if (item_count == 0)
+      return false;
+    --item_count;
+    return true;
+  }
+
+  bool empty() const { return item_count == 0; }
+
+  // Empties the store for all practical purposes.
+  void reset() { item_count = 0; }
+
+  static void destroy(ArrayStore<T, SIZE> *store) { store->reset(); }
+};
+
+} // namespace __llvm_libc
diff --git a/libc/test/src/__support/CMakeLists.txt b/libc/test/src/__support/CMakeLists.txt
--- a/libc/test/src/__support/CMakeLists.txt
+++ b/libc/test/src/__support/CMakeLists.txt
@@ -63,6 +63,16 @@
     libc.src.__support.CPP.uint
 )
 
+add_libc_unittest(
+  arraystore_test
+  SUITE
+    libc_support_unittests
+  SRCS
+    arraystore_test.cpp
+  DEPENDS
+    libc.src.__support.arraystore
+)
+
 add_executable(
   libc_str_to_float_comparison_test
   str_to_float_comparison_test.cpp
diff --git a/libc/test/src/__support/arraystore_test.cpp b/libc/test/src/__support/arraystore_test.cpp
new file mode 100644
--- /dev/null
+++ b/libc/test/src/__support/arraystore_test.cpp
@@ -0,0 +1,45 @@
+//===-- Unittests for ArrayStore ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/arraystore.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcArrayStoreTest, PushAndPop) {
+  __llvm_libc::ArrayStore<int, 20> array_store;
+  ASSERT_TRUE(array_store.empty());
+  for (int i = 0; i < 20; i++)
+    ASSERT_TRUE(array_store.push_back(i));
+  ASSERT_FALSE(array_store.empty());
+  ASSERT_FALSE(array_store.push_back(123));
+  for (int i = 20; i > 0; --i) {
+    ASSERT_EQ(array_store.back(), i - 1);
+    ASSERT_TRUE(array_store.pop_back());
+  }
+  ASSERT_FALSE(array_store.pop_back());
+  ASSERT_TRUE(array_store.empty());
+}
+
+TEST(LlvmLibcArrayStoreTest, Reset) {
+  __llvm_libc::ArrayStore<int, 20> array_store;
+  ASSERT_TRUE(array_store.empty());
+  for (int i = 0; i < 20; i++)
+    ASSERT_TRUE(array_store.push_back(i));
+  ASSERT_FALSE(array_store.empty());
+  array_store.reset();
+  ASSERT_TRUE(array_store.empty());
+}
+
+TEST(LlvmLibcArrayStoreTest, Destroy) {
+  __llvm_libc::ArrayStore<int, 20> array_store;
+  ASSERT_TRUE(array_store.empty());
+  for (int i = 0; i < 20; i++)
+    ASSERT_TRUE(array_store.push_back(i));
+  ASSERT_FALSE(array_store.empty());
+  __llvm_libc::ArrayStore<int, 20>::destroy(&array_store);
+  ASSERT_TRUE(array_store.empty());
+}