diff --git a/CMake/install_test_project/CMakeLists.txt b/CMake/install_test_project/CMakeLists.txt
new file mode 100644
index 000000000..b8e27dd1a
--- /dev/null
+++ b/CMake/install_test_project/CMakeLists.txt
@@ -0,0 +1,27 @@
+#
+# Copyright 2019 The Abseil Authors.
+#
+# 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
+#
+#    https://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.
+
+# A simple CMakeLists.txt for testing cmake installation
+
+cmake_minimum_required(VERSION 3.5)
+project(absl_cmake_testing)
+
+set(CMAKE_CXX_STANDARD 11)
+
+add_executable(simple simple.cc)
+
+find_package(absl REQUIRED)
+
+target_link_libraries(simple absl::strings)
diff --git a/CMake/install_test_project/simple.cc b/CMake/install_test_project/simple.cc
new file mode 100644
index 000000000..e9e352912
--- /dev/null
+++ b/CMake/install_test_project/simple.cc
@@ -0,0 +1,23 @@
+//
+// Copyright 2019 The Abseil Authors.
+//
+// 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
+//
+//    https://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 <iostream>
+#include "absl/strings/substitute.h"
+
+int main(int argc, char** argv) {
+  for (int i = 0; i < argc; ++i) {
+    std::cout << absl::Substitute("Arg $0: $1\n", i, argv[i]);
+  }
+}
diff --git a/CMake/install_test_project/test.sh b/CMake/install_test_project/test.sh
new file mode 100755
index 000000000..4b19bb558
--- /dev/null
+++ b/CMake/install_test_project/test.sh
@@ -0,0 +1,105 @@
+#!/bin/bash
+#
+# Copyright 2019 The Abseil Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# "Unit" and integration tests for Absl CMake installation
+
+# TODO(absl-team): This script isn't fully hermetic because
+# -DABSL_USE_GOOGLETEST_HEAD=ON means that this script isn't pinned to a fixed
+# version of GoogleTest. This means that an upstream change to GoogleTest could
+# break this test. Fix this by allowing this script to pin to a known-good
+# version of GoogleTest.
+
+# Fail on any error. Treat unset variables an error. Print commands as executed.
+set -euox pipefail
+absl_dir=/abseil-cpp
+absl_build_dir=/buildfs/absl-build
+project_dir="${absl_dir}"/CMake/install_test_project
+project_build_dir=/buildfs/project-build
+install_dir="${project_build_dir}"/install
+
+install_absl() {
+  if [[ "${#}" -eq 1 ]]; then
+    cmake -DCMAKE_INSTALL_PREFIX="${1}" -B "${absl_build_dir}" -S "${absl_dir}"
+  else
+    cmake -B "${absl_build_dir}" -S "${absl_dir}"
+  fi
+  cmake --build "${absl_build_dir}" --target install -- -j
+}
+
+uninstall_absl() {
+  xargs rm < "${absl_build_dir}"/install_manifest.txt
+  rm -rf "${absl_build_dir}"
+}
+
+# Test build, install, and link against installed abseil
+install_absl "${install_dir}"
+cmake \
+  -H"${project_dir}" \
+  -B"${project_build_dir}" \
+  -DCMAKE_PREFIX_PATH="${install_dir}"
+cmake --build "${project_build_dir}" --target simple
+
+output="$(${project_build_dir}/simple "printme" 2>&1)"
+if [[ "${output}" != *"Arg 1: printme"* ]]; then
+  echo "Faulty output on simple project:"
+  echo "${output}"
+  exit 1
+fi
+
+# Test that we haven't accidentally made absl::abslblah
+pushd "${install_dir}"
+
+# Starting in CMake 3.12 the default install dir is lib$bit_width
+if [[ -d lib ]]; then
+  libdir="lib"
+elif [[ -d lib64 ]]; then
+  libdir="lib64"
+else
+  echo "ls *, */*, */*/*:"
+  ls *
+  ls */*
+  ls */*/*
+  echo "unknown lib dir"
+fi
+
+if ! grep absl::strings "${libdir}"/cmake/absl/abslTargets.cmake;  then
+  cat "${libdir}"/cmake/absl/abslTargets.cmake
+  echo "CMake targets named incorrectly"
+  exit 1
+fi
+
+uninstall_absl
+popd
+
+# Test that we warn if installed without a prefix or a system prefix
+output="$(install_absl 2>&1)"
+if [[ "${output}" != *"Please set CMAKE_INSTALL_PREFIX"* ]]; then
+  echo "Install without prefix didn't warn as expected. Output:"
+  echo "${output}"
+  exit 1
+fi
+uninstall_absl
+
+output="$(install_absl /usr 2>&1)"
+if [[ "${output}" != *"Please set CMAKE_INSTALL_PREFIX"* ]]; then
+  echo "Install with /usr didn't warn as expected. Output:"
+  echo "${output}"
+  exit 1
+fi
+uninstall_absl
+
+echo "Install test complete!"
+exit 0
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e3bb8d052..3f4fbdcfc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -121,17 +121,17 @@ add_subdirectory(absl)
 # install as a subdirectory only
 install(EXPORT ${PROJECT_NAME}Targets
   NAMESPACE absl::
-  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake"
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
 )
 
 configure_package_config_file(
   CMake/abslConfig.cmake.in
   "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
-  INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake"
+  INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
 )
 
 install(FILES "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
 )
 
 install(DIRECTORY absl
diff --git a/absl/types/optional.h b/absl/types/optional.h
index 58906aa46..f0ae9a173 100644
--- a/absl/types/optional.h
+++ b/absl/types/optional.h
@@ -36,6 +36,7 @@
 #define ABSL_TYPES_OPTIONAL_H_
 
 #include "absl/base/config.h"
+#include "absl/memory/memory.h"
 #include "absl/utility/utility.h"
 
 #ifdef ABSL_HAVE_STD_OPTIONAL
@@ -60,7 +61,6 @@ using std::nullopt;
 #include <utility>
 
 #include "absl/base/attributes.h"
-#include "absl/memory/memory.h"
 #include "absl/meta/type_traits.h"
 #include "absl/types/bad_optional_access.h"
 
@@ -400,23 +400,24 @@ class optional_assign_base<copy_traits::non_movable> {
 };
 
 template <typename T>
-constexpr copy_traits get_ctor_copy_traits() {
-  return std::is_copy_constructible<T>::value
-             ? copy_traits::copyable
-             : std::is_move_constructible<T>::value ? copy_traits::movable
-                                                    : copy_traits::non_movable;
-}
+struct ctor_copy_traits {
+  static constexpr copy_traits traits =
+      std::is_copy_constructible<T>::value
+          ? copy_traits::copyable
+          : std::is_move_constructible<T>::value ? copy_traits::movable
+                                                 : copy_traits::non_movable;
+};
 
 template <typename T>
-constexpr copy_traits get_assign_copy_traits() {
-  return absl::is_copy_assignable<T>::value &&
-                 std::is_copy_constructible<T>::value
-             ? copy_traits::copyable
-             : absl::is_move_assignable<T>::value &&
-                       std::is_move_constructible<T>::value
-                   ? copy_traits::movable
-                   : copy_traits::non_movable;
-}
+struct assign_copy_traits {
+  static constexpr copy_traits traits =
+      absl::is_copy_assignable<T>::value && std::is_copy_constructible<T>::value
+          ? copy_traits::copyable
+          : absl::is_move_assignable<T>::value &&
+                    std::is_move_constructible<T>::value
+                ? copy_traits::movable
+                : copy_traits::non_movable;
+};
 
 // Whether T is constructible or convertible from optional<U>.
 template <typename T, typename U>
@@ -482,9 +483,9 @@ struct optional_hash_base<T, decltype(std::hash<absl::remove_const_t<T> >()(
 template <typename T>
 class optional : private optional_internal::optional_data<T>,
                  private optional_internal::optional_ctor_base<
-                     optional_internal::get_ctor_copy_traits<T>()>,
+                     optional_internal::ctor_copy_traits<T>::traits>,
                  private optional_internal::optional_assign_base<
-                     optional_internal::get_assign_copy_traits<T>()> {
+                     optional_internal::assign_copy_traits<T>::traits> {
   using data_base = optional_internal::optional_data<T>;
 
  public:
diff --git a/ci/cmake_install_test.sh b/ci/cmake_install_test.sh
new file mode 100755
index 000000000..e54b78379
--- /dev/null
+++ b/ci/cmake_install_test.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+#
+# Copyright 2019 The Abseil Authors.
+#
+# 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
+#
+#    https://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.
+
+set -euox pipefail
+
+if [ -z ${ABSEIL_ROOT:-} ]; then
+  ABSEIL_ROOT="$(realpath $(dirname ${0})/..)"
+fi
+
+time docker run \
+    --volume="${ABSEIL_ROOT}:/abseil-cpp:ro" \
+    --workdir=/abseil-cpp \
+    --tmpfs=/buildfs:exec \
+    --cap-add=SYS_PTRACE \
+    --rm \
+    -e CFLAGS="-Werror" \
+    -e CXXFLAGS="-Werror" \
+    gcr.io/google.com/absl-177019/linux_gcc-4.8:20190316 \
+    /bin/bash CMake/install_test_project/test.sh
+