diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..07857ef
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,74 @@
+cmake_minimum_required(VERSION 3.26)
+
+#---------------------------------------------------------------------------------------
+# Compiler config
+#---------------------------------------------------------------------------------------
+if(NOT DEFINED CMAKE_CXX_STANDARD)
+  set(CMAKE_CXX_STANDARD 20)
+endif()
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+#=============================
+project(samples LANGUAGES CXX)
+#=============================
+
+include(cmake/options.cmake)
+
+# ---- Setup default project_options ----
+
+# cmake-format: off
+project_options(
+  # PREFIX ${PROJECT_NAME}
+  ENABLE_CACHE
+  #NO! ENABLE_CLANG_TIDY
+  ${ENABLE_COVERAGE}
+  ${OPTION_ENABLED_SANITIZER}
+  #XXX ENABLE_SANITIZER_ADDRESS
+  #XXX ENABLE_SANITIZER_UNDEFINED_BEHAVIOR
+  #XXX ENABLE_SANITIZER_THREAD
+  #XXX ENABLE_SANITIZER_MEMORY
+  WARNINGS_AS_ERRORS
+)
+# cmake-format: on
+
+target_compile_features(project_options INTERFACE cxx_std_${CMAKE_CXX_STANDARD})
+
+enable_testing()
+
+# ---- Setup experimental cmake C++20 module support ----
+
+# see https://releases.llvm.org/15.0.0/projects/libcxx/docs/ReleaseNotes.html
+#XXX add_compile_options(-fexperimental-library)
+#XXX add_link_options(-lc++experimental)
+
+set(CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API 2182bf5c-ef0d-489a-91da-49dbc3090d2a)
+set(CMake_TEST_CXXModules_UUID "a246741c-d067-4019-a8fb-3d16b0c9d1d3")
+
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+  # string(CONCAT CMAKE_EXPERIMENTAL_CXX_SCANDEP_SOURCE
+  #               "<CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -E -x c++ <SOURCE>"
+  #               " -MT <DYNDEP_FILE> -MD -MF <DEP_FILE>"
+  #               " -fmodules-ts -fdep-file=<DYNDEP_FILE> -fdep-output=<OBJECT> -fdep-format=trtbd"
+  #               " -o <PREPROCESSED_SOURCE>"
+  # )
+  # set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FORMAT "gcc")
+  # set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FLAG "-fmodules-ts -fmodule-mapper=<MODULE_MAP_FILE> -fdep-format=trtbd -x c++")
+
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
+  set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FORMAT "clang")
+  set(CMAKE_EXE_LINKER_FLAGS -lstdc++)
+  # Workaround for C++Modules: Missing module map flags in exported compile commands
+  # see https://gitlab.kitware.com/cmake/cmake/-/issues/24618
+  set(CMAKE_CXX_COMPILE_OBJECT "${CMAKE_CXX_COMPILE_OBJECT} @<OBJECT>.modmap")
+
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+  set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
+
+endif()
+
+add_subdirectory(testsimple)
+add_subdirectory(testall)
+
diff --git a/cmake/CPM.cmake b/cmake/CPM.cmake
new file mode 100644
index 0000000..a3086b7
--- /dev/null
+++ b/cmake/CPM.cmake
@@ -0,0 +1,33 @@
+set(CPM_DOWNLOAD_VERSION 0.38.1)
+
+if(CPM_SOURCE_CACHE)
+  set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+elseif(DEFINED ENV{CPM_SOURCE_CACHE})
+  set(CPM_DOWNLOAD_LOCATION "$ENV{CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+else()
+  set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+endif()
+
+# Expand relative path. This is important if the provided path contains a tilde (~)
+get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)
+
+function(download_cpm)
+  message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+  file(DOWNLOAD
+       https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+       ${CPM_DOWNLOAD_LOCATION}
+  )
+endfunction()
+
+if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
+  download_cpm()
+else()
+  # resume download if it previously failed
+  file(READ ${CPM_DOWNLOAD_LOCATION} check)
+  if("${check}" STREQUAL "")
+    download_cpm()
+  endif()
+  unset(check)
+endif()
+
+include(${CPM_DOWNLOAD_LOCATION})
diff --git a/cmake/options.cmake b/cmake/options.cmake
new file mode 100644
index 0000000..c30a54b
--- /dev/null
+++ b/cmake/options.cmake
@@ -0,0 +1,87 @@
+include_guard()
+
+if(PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
+  message(
+    FATAL_ERROR
+      "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there."
+  )
+endif()
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+set(CMAKE_DEBUG_POSTFIX D)
+set(CMAKE_SKIP_INSTALL_RULES ON)
+
+option(OPTION_ENABLE_UNITY "Enable Unity builds of project" OFF)
+option(OPTION_ENABLE_CLANG_TIDY "Enable clang-tdiy as prebuild step" OFF)
+option(BUILD_SHARED_LIBS "Global flag to cause add_library() to create shared libraries if on." OFF)
+
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  if(APPLE)
+    set(OPTION_ENABLED_SANITIZER
+        "ENABLE_SANITIZER_ADDRESS; ENABLE_SANITIZER_UNDEFINED_BEHAVIOR"
+        CACHE STRING "Enabled sanitizer for debug build"
+    )
+  else()
+    set(OPTION_ENABLED_SANITIZER
+        "ENABLE_SANITIZER_MEMORY"
+        CACHE STRING "Enabled sanitizer for debug build"
+    )
+  endif()
+endif()
+
+option(OPTION_ENABLE_COVERAGE "Enable test coverage of projects" OFF)
+if(OPTION_ENABLE_COVERAGE)
+  set(ENABLE_COVERAGE "ENABLE_COVERAGE")
+endif()
+
+if(OPTION_ENABLE_UNITY)
+  set(ENABLE_UNITY "ENABLE_UNITY")
+endif()
+
+if(CMAKE_EXPORT_COMPILE_COMMANDS)
+  set(CMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES ${CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES})
+endif()
+
+include(${CMAKE_CURRENT_LIST_DIR}/CPM.cmake)
+
+cpmaddpackage("gh:aminya/project_options@0.29.0")
+list(APPEND CMAKE_MODULE_PATH ${project_options_SOURCE_DIR}/src)
+
+# Disable clang-tidy for target
+macro(target_disable_clang_tidy TARGET)
+  find_program(CLANGTIDY clang-tidy)
+  if(CLANGTIDY)
+    set_target_properties(${TARGET} PROPERTIES C_CLANG_TIDY "")
+    set_target_properties(${TARGET} PROPERTIES CXX_CLANG_TIDY "")
+  endif()
+endmacro()
+
+macro(check_system_property DIRECTORY)
+  get_property(
+    _value
+    DIRECTORY ${DIRECTORY}
+    PROPERTY SYSTEM
+    SET
+  )
+  if(NOT _value)
+    message(SEND_ERROR "SYSTEM property is NOT defined for ${DIRECTORY}")
+  endif()
+endmacro()
+
+macro(set_system_property DIRECTORY)
+  message(TRACE "${DIRECTORY}")
+  set_property(DIRECTORY ${DIRECTORY} PROPERTY SYSTEM ON)
+  check_system_property(${DIRECTORY})
+endmacro()
+
+macro(add_tests FILES)
+  foreach(source IN LISTS ${FILES})
+    string(REGEX REPLACE "\.cpp$" "" program ${source})
+    add_executable(${program} ${program}.cpp)
+    set_target_properties(${program} PROPERTIES CXX_STANDARD ${CMAKE_CXX_STANDARD})
+    if(CMAKE_SKIP_INSTALL_RULES OR CMAKE_BUILD_TYPE STREQUAL "Debug")
+      target_link_libraries(${program} PRIVATE $<BUILD_INTERFACE:project_warnings project_options>)
+    endif()
+    add_test(NAME ${program} COMMAND ${program})
+  endforeach()
+endmacro()
diff --git a/testall/CMakeLists.txt b/testall/CMakeLists.txt
new file mode 100644
index 0000000..f56044e
--- /dev/null
+++ b/testall/CMakeLists.txt
@@ -0,0 +1,27 @@
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+  add_compile_options(-Wno-unused-command-line-argument)
+endif()
+
+#
+# module with partitions
+#
+add_library(testall)
+target_sources(
+  testall
+  PRIVATE modall_impl.cpp
+  PUBLIC FILE_SET
+         cxx_modules
+         TYPE
+         CXX_MODULES
+         FILES
+            modall_if.cppm
+            modall_ifpart.cppm  # interface partition
+            modall_part.cppm    # internal partition
+)
+set_target_properties(testall PROPERTIES CXX_STANDARD ${CMAKE_CXX_STANDARD})
+if(CMAKE_SKIP_INSTALL_RULES AND CMAKE_BUILD_TYPE STREQUAL "Debug")
+  target_link_libraries(testall PUBLIC $<BUILD_INTERFACE:project_warnings project_options>)
+endif()
+add_executable(modall_test modall_test.cpp)
+target_link_libraries(modall_test testall)
+add_test(NAME modall_test COMMAND modall_test)
diff --git a/testsimple/CMakeLists.txt b/testsimple/CMakeLists.txt
new file mode 100644
index 0000000..f2108af
--- /dev/null
+++ b/testsimple/CMakeLists.txt
@@ -0,0 +1,24 @@
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+  add_compile_options(-Wno-unused-command-line-argument)
+endif()
+
+#
+# module with partitions
+#
+add_library(testsimple)
+target_sources(
+  testsimple
+  PUBLIC FILE_SET
+         cxx_modules
+         TYPE
+         CXX_MODULES
+         FILES
+            modsimple_if.cppm
+)
+set_target_properties(testsimple PROPERTIES CXX_STANDARD ${CMAKE_CXX_STANDARD})
+if(CMAKE_SKIP_INSTALL_RULES AND CMAKE_BUILD_TYPE STREQUAL "Debug")
+  target_link_libraries(testsimple PUBLIC $<BUILD_INTERFACE:project_warnings project_options>)
+endif()
+add_executable(modsimple_test modsimple_test.cpp)
+target_link_libraries(modsimple_test testsimple)
+add_test(NAME modsimple_test COMMAND modsimple_test)
diff --git a/testsimple/modsimple_if.cppm b/testsimple/modsimple_if.cppm
index 5ae557c..ddbd7bf 100644
--- a/testsimple/modsimple_if.cppm
+++ b/testsimple/modsimple_if.cppm
@@ -19,10 +19,10 @@ export class Square {
  private:
    int value;
  public:
-   Square(int i) 
+   Square(int i)
     : value{square(i)} {
    }
-   int getValue() const {
+   [[nodiscard]] int getValue() const {
      return value;
    }
 };