fix argument passing

* update URLs for new CPM.cmake organisation

* trigger travis

.clang-format

@@ -0,0 +1,16 @@
+---
+  BasedOnStyle: Google
+  AccessModifierOffset: '-2'
+  AlignTrailingComments: 'true'
+  AllowAllParametersOfDeclarationOnNextLine: 'false'
+  AlwaysBreakTemplateDeclarations: 'No'
+  BreakBeforeBraces: Attach
+  ColumnLimit: '100'
+  ConstructorInitializerAllOnOneLineOrOnePerLine: 'true'
+  IncludeBlocks: Regroup
+  IndentPPDirectives: AfterHash
+  IndentWidth: '2'
+  NamespaceIndentation: All
+  BreakBeforeBinaryOperators: All
+  BreakBeforeTernaryOperators: 'true'
+...

.cmake-format

@@ -0,0 +1,71 @@
+format:
+  tab_size: 2
+  line_width: 100
+  dangle_parens: true
+
+parse:
+  additional_commands:
+    cpmaddpackage:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: CPMAddPackage
+      kwargs: &cpmaddpackagekwargs
+        NAME: 1
+        FORCE: 1
+        VERSION: 1
+        GIT_TAG: 1
+        DOWNLOAD_ONLY: 1
+        GITHUB_REPOSITORY: 1
+        GITLAB_REPOSITORY: 1
+        GIT_REPOSITORY: 1
+        SVN_REPOSITORY: 1
+        SVN_REVISION: 1
+        SOURCE_DIR: 1
+        DOWNLOAD_COMMAND: 1
+        FIND_PACKAGE_ARGUMENTS: 1
+        NO_CACHE: 1
+        GIT_SHALLOW: 1
+        URL: 1
+        URL_HASH: 1
+        URL_MD5: 1
+        DOWNLOAD_NAME: 1
+        DOWNLOAD_NO_EXTRACT: 1
+        HTTP_USERNAME: 1
+        HTTP_PASSWORD: 1
+        OPTIONS: +
+    cpmfindpackage:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: CPMFindPackage
+      kwargs: *cpmaddpackagekwargs
+    cpmdeclarepackage:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: CPMDeclarePackage
+      kwargs: *cpmaddpackagekwargs
+    packageproject:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: packageProject
+      kwargs:
+        NAME: 1
+        VERSION: 1
+        INCLUDE_DIR: 1
+        INCLUDE_DESTINATION: 1
+        BINARY_DIR: 1
+        COMPATIBILITY: 1
+        VERSION_HEADER: 1
+        DEPENDENCIES: +
+    cpmusepackagelock:
+      pargs: 1
+      spelling: CPMUsePackageLock
+    cpmregisterpackage:
+      pargs: 1
+      spelling: CPMRegisterPackage
+    cpmgetpackageversion:
+      pargs: 2
+      spelling: CPMGetPackageVersion

.github/workflows/macos.yml

@@ -0,0 +1,22 @@
+name: MacOS
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+
+    runs-on: macos-latest
+    
+    steps:
+    - uses: actions/checkout@v1
+    
+    - name: run tests
+      run: |
+        cmake -Htest -Bbuild/test
+        cmake --build build/test --target test-verbose

.github/workflows/publish.yaml

@@ -0,0 +1,28 @@
+name: Publish
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  build:
+    name: Publish CPM.cmake
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+
+      - name: Set CPM version by tag
+        run: |
+          mkdir dist
+          sed "s/1.0.0-development-version/${GITHUB_REF/refs\/tags\/v}/g" cmake/CPM.cmake > dist/CPM.cmake
+          sed "s/1.0.0-development-version/${GITHUB_REF/refs\/tags\/v}/g" cmake/get_cpm.cmake > dist/get_cpm.cmake
+
+      - name: Upload CPM.cmake to release
+        uses: svenstaro/upload-release-action@v1-release
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          tag: ${{ github.ref }}
+          file: dist/*.cmake
+          file_glob: true
+          overwrite: true

.github/workflows/style.yml

@@ -0,0 +1,28 @@
+name: Style
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  style:
+
+    runs-on: macos-latest
+    
+    steps:
+    - uses: actions/checkout@v1
+    
+    - name: Install format dependencies
+      run: |
+        brew install clang-format
+        pip3 install cmake_format==0.6.11 pyyaml
+
+    - name: configure
+      run: cmake -Htest/style -Bbuild/style
+
+    - name: check style
+      run: cmake --build build/style --target check-format

.github/workflows/ubuntu.yml

@@ -0,0 +1,29 @@
+name: Ubuntu
+
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v1
+    
+    - name: install updates
+      run: |
+        wget -O cmake.sh https://cmake.org/files/v3.14/cmake-3.14.0-Linux-x86_64.sh 
+        sudo sh cmake.sh --skip-license --exclude-subdir --prefix=/usr/local
+        export PATH=/usr/local/bin:$PATH
+        cmake --version
+    
+    - name: run tests
+      run: |
+        cmake -Htest -Bbuild/test
+        cmake --build build/test --target test-verbose

.github/workflows/windows.yml

@@ -0,0 +1,22 @@
+name: Windows
+
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+jobs:
+  build:
+
+    runs-on: windows-latest
+    
+    steps:
+    - uses: actions/checkout@v1
+    
+    - name: run tests
+      run: |
+        cmake -Htest -Bbuild/test
+        cmake --build build/test --target test-verbose

.gitignore

@@ -1,10 +1,4 @@
-CMakeCache.txt
-CMakeFiles
-CMakeScripts
-Testing
-Makefile
-cmake_install.cmake
-install_manifest.txt
-compile_commands.json
-CTestTestfile.cmake
-build
+build/
+/build*
+/.vscode
+*.DS_Store

.travis.yml

@@ -1,11 +1,13 @@
-
 language: cpp
 sudo: require
+dist: xenial
 
 common_sources: &all_sources
   - ubuntu-toolchain-r-test
   - llvm-toolchain-trusty
-  - llvm-toolchain-trusty-6.0
+
+python:
+  - 3.7
 
 matrix:
   include:
@@ -14,7 +16,7 @@ matrix:
       addons: &gcc8
         apt:
           sources: *all_sources
-          packages: 
+          packages:
             - g++-8
       env:
         - MATRIX_EVAL="export CC=gcc-8; export CXX=g++-8;"
@@ -22,11 +24,11 @@ matrix:
     - os: linux
       compiler: clang
       addons:
-          apt:
-              sources: *all_sources
-              packages:
-                - g++-8
-                - clang-6.0
+        apt:
+          sources: *all_sources
+          packages:
+            - g++-8
+            - clang-6.0
       env:
         - MATRIX_EVAL="export CC=clang-6.0; export CXX=clang++-6.0;"
 
@@ -35,16 +37,14 @@ before_install:
   - eval "${MATRIX_EVAL}"
   - echo "CC=$CC CXX=$CXX"
   # Install a supported cmake version (>= 3.14)
-  - wget -O cmake.sh https://cmake.org/files/v3.14/cmake-3.14.0-Linux-x86_64.sh 
+  - wget -O cmake.sh https://cmake.org/files/v3.14/cmake-3.14.0-Linux-x86_64.sh
   - sudo sh cmake.sh --skip-license --exclude-subdir --prefix=/usr/local
   - export PATH=/usr/local/bin:$PATH
   - cmake --version
 
 script:
-  - cmake -Hexamples/simple -Bbuild/simple 
-  - cmake --build build/simple
-  - CTEST_OUTPUT_ON_FAILURE=1 cmake --build build/simple --target test
-  - cmake -Hexamples/complex -Bbuild/complex
-  - cmake --build build/complex
-  - CTEST_OUTPUT_ON_FAILURE=1 cmake --build build/complex --target test
- 
+  # unit tests
+  - cmake -Htest -Bbuild/test
+  - cmake --build build/test --target test-verbose
+  # build examples
+  - python3 examples/build_all.py

README.md

@@ -1,16 +1,62 @@
-[![Build Status](https://travis-ci.com/TheLartians/CPM.svg?branch=master)](https://travis-ci.com/TheLartians/CPM)
+[![Build Status](https://travis-ci.com/cpm-cmake/CPM.cmake.svg?branch=master)](https://travis-ci.com/cpm-cmake/CPM.cmake)
+[![Actions Status](https://github.com/cpm-cmake/CPM.cmake/workflows/MacOS/badge.svg)](https://github.com/cpm-cmake/CPM.cmake/actions)
+[![Actions Status](https://github.com/cpm-cmake/CPM.cmake/workflows/Windows/badge.svg)](https://github.com/cpm-cmake/CPM.cmake/actions)
+[![Actions Status](https://github.com/cpm-cmake/CPM.cmake/workflows/Ubuntu/badge.svg)](https://github.com/cpm-cmake/CPM.cmake/actions)
 
-# CPM
+<br />
+<p align="center">
+  <img src="./logo/CPM.png" height="100" />
+</p>
+<br />
 
-CPM is a simple GIT dependency manager written in CMake. The main use-case is abstracting CMake's `FetchContent` and managing dependencies in small to medium sized projects.
+# Setup-free CMake dependency management
 
-# Supported projects
+CPM.cmake is a CMake script that adds dependency management capabilities to CMake.
+It's built as a thin wrapper around CMake's [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html) module that adds version control, caching, a simple API [and more](#comparison-to-pure-fetchcontent--externalproject).
 
-Any project that you can add via `add_subdirectory` should already work with CPM.
+## Manage everything
 
-# Usage
+Any downloadable project or resource can be added as a version-controlled dependency though CPM, it is not necessary to modify or package anything.
+Projects using modern CMake are automatically configured and their targets can be used immediately.
+For everything else, the targets can be created manually after the dependency has been downloaded (see the [snippets](#snippets) below for examples).
 
-To add a new dependency to your project simply add the Projects target name, the git URL and the version. If the git tag for this version does not match the pattern `v$VERSION`, then the exact branch or tag can be specified with the `GIT_TAG` argument. CMake options can also be supplied with the package.
+## Further reading
+
+- [CPM: An Awesome Dependency Manager for C++ with CMake](https://medium.com/swlh/cpm-an-awesome-dependency-manager-for-c-with-cmake-3c53f4376766)
+- [CMake and the Future of C++ Package Management](https://ibob.github.io/blog/2020/01/13/cmake-package-management/)
+
+## Usage
+
+After `CPM.cmake` has been [added](#adding-cpm) to your project, the function `CPMAddPackage` or `CPMFindPackage` can be used to fetch and configure a dependency.
+Afterwards, any targets defined in the dependency can be used directly.
+`CPMFindPackage` and `CPMAddPackage` take the following named parameters.
+
+```cmake
+CPMAddPackage(
+  NAME          # The unique name of the dependency (should be the exported target's name)
+  VERSION       # The minimum version of the dependency (optional, defaults to 0)
+  OPTIONS       # Configuration options passed to the dependency (optional)
+  DOWNLOAD_ONLY # If set, the project is downloaded, but not configured (optional)
+  [...]         # Origin parameters forwarded to FetchContent_Declare, see below
+)
+```
+
+The origin may be specified by a `GIT_REPOSITORY`, but other sources, such as direct URLs, are [also supported](https://cmake.org/cmake/help/v3.11/module/ExternalProject.html#external-project-definition).
+If `GIT_TAG` hasn't been explicitly specified it defaults to `v(VERSION)`, a common convention for git projects.
+On the other hand, if `VERSION` hasn't been explicitly specified, CPM can automatically identify the version from the git tag in some common cases. 
+`GIT_TAG` can also be set to a specific commit or a branch name such as `master` to always download the most recent version.
+The optional argument `FIND_PACKAGE_ARGUMENTS` can be specified to a string of parameters that will be passed to `find_package` if enabled (see below).
+
+After calling `CPMAddPackage` or `CPMFindPackage`, the following variables are defined in the local scope, where `<dependency>` is the name of the dependency.
+
+- `<dependency>_SOURCE_DIR` is the path to the source of the dependency.
+- `<dependency>_BINARY_DIR` is the path to the build directory of the dependency.
+- `<dependency>_ADDED` is set to `YES` if the dependency has not been added before, otherwise it is set to `NO`.
+
+The difference between `CPMFindPackage` and `CPMAddPackage` is that `CPMFindPackage` will try to find a local dependency via CMake's `find_package` and fallback to `CPMAddPackage` if the dependency is not found.
+This behaviour can be also modified globally via [CPM options](#options).
+
+## Full CMakeLists Example
 
 ```cmake
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
@@ -18,47 +64,311 @@ cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 # create project
 project(MyProject)
 
+# add executable
+add_executable(tests tests.cpp)
+
 # add dependencies
-include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/CPM.cmake)
+include(cmake/CPM.cmake)
 
 CPMAddPackage(
-  NAME LarsParser
-  VERSION 1.8
-  GIT_REPOSITORY https://github.com/TheLartians/Parser.git
-  GIT_TAG v1.8 # optional here, as indirectly defined by VERSION
-  OPTIONS      # optional CMake arguments passed to the dependency
-    "LARS_PARSER_BUILD_GLUE_EXTENSION ON"
+  NAME Catch2
+  GITHUB_REPOSITORY catchorg/Catch2
+  VERSION 2.5.0
 )
 
-# add executable
-set (CMAKE_CXX_STANDARD 17)
-add_executable(my-project my-project.cpp)
-target_link_libraries(my-project LarsParser)
+# link dependencies
+target_link_libraries(tests Catch2)
 ```
 
-See the [examples directory](https://github.com/TheLartians/CPM/tree/master/examples) for more examples.
+See the [examples directory](https://github.com/cpm-cmake/CPM.cmake/tree/master/examples) for complete examples with source code and check [below](#snippets) or in the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/More-Snippets) for example snippets.
 
-# Adding CPM
+## Adding CPM
 
-To add CPM to your current project, simply include add `cmake/CPM.cmake` to your projects `cmake` directory. The command below will perform this automatically.
+To add CPM to your current project, simply add the [latest release](https://github.com/cpm-cmake/CPM.cmake/releases/latest) of `CPM.cmake` or `get_cpm.cmake` to your project's `cmake` directory.
+The command below will perform this automatically.
 
 ```bash
-wget -O cmake/CPM.cmake https://raw.githubusercontent.com/TheLartians/CPM/master/cmake/CPM.cmake
+mkdir -p cmake
+wget -O cmake/CPM.cmake https://github.com/cpm-cmake/CPM.cmake/releases/latest/download/get_cpm.cmake
 ```
 
-# Options
+You can also download CPM.cmake directly from your project's `CMakeLists.txt`. See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Downloading-CPM.cmake-in-CMake) for more details.
 
-If you set the CMake option `CPM_REMOTE_PACKAGES_ONLY` to `On`, packages will always be fetched via the URL. Setting `CPM_LOCAL_PACKAGES_ONLY` to `On` will only add packages via `find_package`.
+## Updating CPM
 
-# Advantages
+To update CPM to the newest version, update the script in the project's root directory, for example by running the command above.
+Dependencies using CPM will automatically use the updated script of the outermost project.
 
-- **Small repos** CPM takes care of project dependencies, allowing you to focus on creating small, well-tested frameworks.
-- **Cross-Plattform** CPM adds projects via `add_subdirectory`, which is compatible with all cmake toolchains and generators.
-- **Reproducable builds** By using versioning via git tags it is ensured that a project will always be in the same state everywhere.
-- **No installation required** No need to install anything. Just add the script to your project and you're good to go.
-- **No Setup required** There is a good chance your existing projects already work as CPM dependencies.
+## Advantages
 
-# Limitations
+- **Small and reusable projects** CPM takes care of all project dependencies, allowing developers to focus on creating small, well-tested libraries.
+- **Cross-Platform** CPM adds projects directly at the configure stage and is compatible with all CMake toolchains and generators.
+- **Reproducible builds** By versioning dependencies via git commits or tags it is ensured that a project will always be buildable.
+- **Recursive dependencies** Ensures that no dependency is added twice and all are added in the minimum required version.
+- **Plug-and-play** No need to install anything. Just add the script to your project and you're good to go.
+- **No packaging required** Simply add all external sources as a dependency.
+- **Simple source distribution** CPM makes including projects with source files and dependencies easy, reducing the need for monolithic header files or git submodules.
 
-- **First version used** In diamond-shaped dependency graphs (e.g. `A` depends on `C`(v1.1) and `A` depends on `B` depends on `C`(v1.2)) the first added dependency will be used (in this case `C`@1.1). If the current version is older than the version beeing added, or if provided options are incompatible, a CMake warning will be emitted.
-- **No auto-update** To update a dependency, version numbers or git tags in the cmake scripts must be adapted manually.
+## Limitations
+
+- **No pre-built binaries** For every new build directory, all dependencies are initially downloaded and built from scratch. To avoid extra downloads it is recommend to set the [`CPM_SOURCE_CACHE`](#CPM_SOURCE_CACHE) environmental variable. Using a caching compiler such as [ccache](https://github.com/TheLartians/Ccache.cmake) can drastically reduce build time.
+- **Dependent on good CMakeLists** Many libraries do not have CMakeLists that work well for subprojects. Luckily this is slowly changing, however, until then, some manual configuration may be required (see the snippets [below](#snippets) for examples). For best practices on preparing projects for CPM, see the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Preparing-projects-for-CPM.cmake). 
+- **First version used** In diamond-shaped dependency graphs (e.g. `A` depends on `C`@1.1 and `B`, which itself depends on `C`@1.2 the first added dependency will be used (in this case `C`@1.1). In this case, B requires a newer version of `C` than `A`, so CPM will emit a warning. This can be easily resolved by adding a new version of the dependency in the outermost project, or by introducing a [package lock file](#package-lock).
+
+For projects with more complex needs and where an extra setup step doesn't matter, it may be worth to check out an external C++ package manager such as [vcpkg](https://github.com/microsoft/vcpkg), [conan](https://conan.io) or [hunter](https://github.com/ruslo/hunter).
+Dependencies added with `CPMFindPackage` should work with external package managers.
+Additionally, the option [`CPM_USE_LOCAL_PACKAGES`](#cpmuselocalpackages) will enable `find_package` for all CPM dependencies.
+
+## Comparison to FindPackage
+
+The usual way to add libraries in CMake projects is to call `find_package(<PackageName>)` and to link against libraries defined in a `<PackageName>_LIBRARIES` variable.
+While simple, this may lead to unpredictable builds, as it requires the library to be installed on the system and it is unclear which version of the library has been added.
+Additionally, it is difficult to cross-compile projects (e.g. for mobile), as the dependencies will need to be rebuilt manually for each targeted architecture.
+
+CPM.cmake allows dependencies to be unambiguously defined and builds them from source.
+Note that the behaviour differs from `find_package`, as variables exported to the parent scope (such as  `<PackageName>_LIBRARIES`) will not be visible after adding a package using CPM.cmake.
+The behaviour can be [achieved manually](https://github.com/cpm-cmake/CPM.cmake/issues/132#issuecomment-644955140), if required.
+
+## Comparison to pure FetchContent / ExternalProject
+
+CPM.cmake is a wrapper for CMake's FetchContent module and adds a number of features that turn it into a useful dependency manager.
+The most notable features are:
+
+- A simpler to use API
+- Version checking: CPM.cmake will check the version number of any added dependency and omit a warning if another dependency requires a more recent version.
+- Options: any Options passed to a dependency are stored and compared on later use, so if another dependency tries to add an existing dependency with incompatible options a warning will be emitted to the user.
+- Offline builds: CPM.cmake will override CMake's download and update commands, which allows new builds to be configured while offline if all dependencies [are available locally](#cpm_source_cache).
+- Automatic shallow clone: if a version tag (e.g. `v2.2.0`) is provided and `CPM_SOURCE_CACHE` is used, CPM.cmake will perform a shallow clone of the dependency, which should be significantly faster while using less storage than a full clone.
+- Overridable: all `CPMAddPackage` can be configured to use `find_package` by setting a [CMake flag](#cpm_use_local_packages), making it easy to integrate into projects that may require local versioning through the system's package manager.
+- [Package lock files](#package-lock) for easier transitive dependency management.
+- Dependencies can be overridden [per-build](#local-package-override) using CMake CLI parameters.
+
+ExternalProject works similarly as FetchContent, however waits with adding dependencies until build time. 
+This has a quite a few disadvantages, especially as it makes using custom toolchains / cross-compiling very difficult and can lead to problems with nested dependencies.
+
+## Options
+
+### CPM_SOURCE_CACHE
+
+To avoid re-downloading dependencies, CPM has an option `CPM_SOURCE_CACHE` that can be passed to CMake as `-DCPM_SOURCE_CACHE=<path to an external download directory>`.
+This will also allow projects to be configured offline, as long as the dependencies have been added to the cache before.
+It may also be defined system-wide as an environmental variable, e.g. by exporting `CPM_SOURCE_CACHE` in your `.bashrc` or `.bash_profile`.
+
+```bash
+export CPM_SOURCE_CACHE=$HOME/.cache/CPM
+```
+
+Note that passing the variable as a configure option to CMake will always override the value set by the environmental variable.
+
+You can use `CPM_SOURCE_CACHE` on GitHub Actions workflows [cache](https://github.com/actions/cache) and combine it with ccache, to make your CI faster. See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Caching-with-CPM.cmake-and-ccache-on-GitHub-Actions) for more info.
+
+### CPM_DOWNLOAD_ALL
+
+If set, CPM will forward all calls to `CPMFindPackage` as `CPMAddPackage`.
+This is useful to create reproducible builds or to determine if the source parameters have all been set correctly.
+This can also be set as an environmental variable.
+
+### CPM_USE_LOCAL_PACKAGES
+
+CPM can be configured to use `find_package` to search for locally installed dependencies first by setting the CMake option `CPM_USE_LOCAL_PACKAGES`.
+If the option `CPM_LOCAL_PACKAGES_ONLY` is set, CPM will emit an error if the dependency is not found locally.
+These options can also be set as environmental variables.
+
+## Local package override
+
+Library developers are often in the situation where they work on a locally checked out dependency at the same time as on a consumer project.
+It is possible to override the consumer's dependency with the version by supplying the CMake option `CPM_<dependency name>_SOURCE` set to the absolute path of the local library.
+For example, to use the local version of the dependency `Dep` at the path `/path/to/dep`, the consumer can be built with the following command. 
+
+```bash
+cmake -Bbuild -DCPM_Dep_SOURCE=/path/to/dep
+```
+
+## Package lock
+
+In large projects with many transitive dependencies, it can be useful to introduce a package lock file.
+This will list all CPM.cmake dependencies and can be used to update dependencies without modifying the original `CMakeLists.txt`.
+To use a package lock, add the following line directly after including CPM.cmake.
+
+```cmake
+CPMUsePackageLock(package-lock.cmake)
+```
+
+To create or update the package lock file, build the `cpm-update-package-lock` target.
+
+```bash
+cmake -Bbuild
+cmake --build build --target cpm-update-package-lock
+```
+
+See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Package-lock) for more info.
+
+## Built with CPM.cmake
+
+Some amazing projects that are built using the CPM.cmake package manager. 
+If you know others, feel free to add them here through a PR.
+
+<table>
+  <tr>
+    <td>
+      <a href="https://bitfieldaudio.com">
+        <p align="center">
+          <img src="https://avatars2.githubusercontent.com/u/40357059?s=200&v=4"  alt="otto-project" height=100pt width=100pt />
+        </p>
+        <p align="center"><b>OTTO - The Open Source GrooveBox</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://maphi.app">
+        <p align="center">
+          <img src="https://user-images.githubusercontent.com/4437447/89892751-71af8000-dbd7-11ea-9d87-4fe107845069.png"  alt="maphi" height=100pt width=100pt />
+        </p>
+        <p align="center"><b>Maphi - the Math App</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/TheLartians/ModernCppStarter">
+        <p align="center">
+          <img src="https://repository-images.githubusercontent.com/254842585/4dfa7580-7ffb-11ea-99d0-46b8fe2f4170"  alt="modern-cpp-starter" height=100pt width=200pt />
+        </p>
+        <p align="center"><b>ModernCppStarter</b></p>
+      </a>
+    </td>
+  </tr>
+</table>
+
+## Snippets
+
+These examples demonstrate how to include some well-known projects with CPM.
+See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/More-Snippets) for more snippets.
+
+### [Catch2](https://github.com/catchorg/Catch2)
+
+```cmake
+CPMAddPackage(
+  NAME Catch2
+  GITHUB_REPOSITORY catchorg/Catch2
+  VERSION 2.5.0
+)
+```
+
+### [Boost (via boost-cmake)](https://github.com/Orphis/boost-cmake)
+
+```CMake
+CPMAddPackage(
+  NAME boost-cmake
+  GITHUB_REPOSITORY Orphis/boost-cmake
+  VERSION 1.67.0
+)
+```
+
+### [cxxopts](https://github.com/jarro2783/cxxopts)
+
+```cmake
+CPMAddPackage(
+  NAME cxxopts
+  GITHUB_REPOSITORY jarro2783/cxxopts
+  VERSION 2.2.0
+  OPTIONS
+    "CXXOPTS_BUILD_EXAMPLES Off"
+    "CXXOPTS_BUILD_TESTS Off"
+)
+```
+
+### [Yaml-cpp](https://github.com/jbeder/yaml-cpp)
+
+```CMake
+CPMAddPackage(
+  NAME yaml-cpp
+  GITHUB_REPOSITORY jbeder/yaml-cpp
+  # 0.6.2 uses deprecated CMake syntax
+  VERSION 0.6.3
+  # 0.6.3 is not released yet, so use a recent commit
+  GIT_TAG 012269756149ae99745b6dafefd415843d7420bb 
+  OPTIONS
+    "YAML_CPP_BUILD_TESTS Off"
+    "YAML_CPP_BUILD_CONTRIB Off"
+    "YAML_CPP_BUILD_TOOLS Off"
+)
+```
+
+### [google/benchmark](https://github.com/google/benchmark)
+
+```cmake
+CPMAddPackage(
+  NAME benchmark
+  GITHUB_REPOSITORY google/benchmark
+  VERSION 1.4.1
+  OPTIONS
+    "BENCHMARK_ENABLE_TESTING Off"
+)
+
+if (benchmark_ADDED)
+  # compile with C++17
+  set_target_properties(benchmark PROPERTIES CXX_STANDARD 17)
+endif()
+```
+
+### [nlohmann/json](https://github.com/nlohmann/json)
+
+```cmake
+CPMAddPackage(
+  NAME nlohmann_json
+  VERSION 3.6.1  
+  # the git repo is incredibly large, so we download the archived include directory
+  URL https://github.com/nlohmann/json/releases/download/v3.6.1/include.zip
+  URL_HASH SHA256=69cc88207ce91347ea530b227ff0776db82dcb8de6704e1a3d74f4841bc651cf
+)
+
+if (nlohmann_json_ADDED)
+  add_library(nlohmann_json INTERFACE IMPORTED)
+  target_include_directories(nlohmann_json INTERFACE ${nlohmann_json_SOURCE_DIR})
+endif()
+```
+
+### [Range-v3](https://github.com/ericniebler/range-v3)
+
+```Cmake
+CPMAddPackage(
+  NAME range-v3
+  URL https://github.com/ericniebler/range-v3/archive/0.5.0.zip
+  VERSION 0.5.0
+  # the range-v3 CMakeLists screws with configuration options
+  DOWNLOAD_ONLY True
+)
+
+if(range-v3_ADDED) 
+  add_library(range-v3 INTERFACE IMPORTED)
+  target_include_directories(range-v3 INTERFACE "${range-v3_SOURCE_DIR}/include")
+endif()
+```
+
+### [Lua](https://www.lua.org)
+
+```cmake
+CPMAddPackage(
+  NAME lua
+  GIT_REPOSITORY https://github.com/lua/lua.git
+  VERSION 5.3.5
+  DOWNLOAD_ONLY YES
+)
+
+if (lua_ADDED)
+  # lua has no CMake support, so we create our own target
+
+  FILE(GLOB lua_sources ${lua_SOURCE_DIR}/*.c)
+  list(REMOVE_ITEM lua_sources "${lua_SOURCE_DIR}/lua.c" "${lua_SOURCE_DIR}/luac.c")
+  add_library(lua STATIC ${lua_sources})
+
+  target_include_directories(lua
+    PUBLIC
+      $<BUILD_INTERFACE:${lua_SOURCE_DIR}>
+  )
+endif()
+```
+
+For a full example on using CPM to download and configure lua with sol2 see [here](examples/sol2).
+
+### Full Examples
+
+See the [examples directory](https://github.com/cpm-cmake/CPM.cmake/tree/master/examples) for full examples with source code and check out the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/More-Snippets) for many more example snippets.

cmake/CPM.cmake

@@ -1,127 +1,715 @@
+# CPM.cmake - CMake's missing package manager
+# ===========================================
+# See https://github.com/cpm-cmake/CPM.cmake for usage and update instructions.
+#
+# MIT License
+# -----------
+#[[
+  Copyright (c) 2021 Lars Melchior and additional contributors
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all
+  copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+]]
+
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
+set(CURRENT_CPM_VERSION 1.0.0-development-version)
+
 if(CPM_DIRECTORY)
-  if(NOT ${CPM_DIRECTORY} MATCHES ${CMAKE_CURRENT_LIST_DIR})
+  if(NOT CPM_DIRECTORY STREQUAL CMAKE_CURRENT_LIST_DIR)
+    if(CPM_VERSION VERSION_LESS CURRENT_CPM_VERSION)
+      message(
+        AUTHOR_WARNING
+          "${CPM_INDENT} \
+A dependency is using a more recent CPM version (${CURRENT_CPM_VERSION}) than the current project (${CPM_VERSION}). \
+It is recommended to upgrade CPM to the most recent version. \
+See https://github.com/cpm-cmake/CPM.cmake for more information."
+      )
+    endif()
+    if(${CMAKE_VERSION} VERSION_LESS "3.17.0")
+      include(FetchContent)
+    endif()
+    return()
+  endif()
+
+  get_property(
+    CPM_INITIALIZED GLOBAL ""
+    PROPERTY CPM_INITIALIZED
+    SET
+  )
+  if(CPM_INITIALIZED)
     return()
   endif()
 endif()
 
-set(CPM_DIRECTORY ${CMAKE_CURRENT_LIST_DIR} CACHE INTERNAL "")
-set(CPM_PACKAGES "" CACHE INTERNAL "")
+set_property(GLOBAL PROPERTY CPM_INITIALIZED true)
 
-option(CPM_LOCAL_PACKAGES_ONLY "Use only locally installed packages" OFF)
-option(CPM_REMOTE_PACKAGES_ONLY "Always download packages" OFF)
+option(CPM_USE_LOCAL_PACKAGES "Always try to use `find_package` to get dependencies"
+       $ENV{CPM_USE_LOCAL_PACKAGES}
+)
+option(CPM_LOCAL_PACKAGES_ONLY "Only use `find_package` to get dependencies"
+       $ENV{CPM_LOCAL_PACKAGES_ONLY}
+)
+option(CPM_DOWNLOAD_ALL "Always download dependencies from source" $ENV{CPM_DOWNLOAD_ALL})
+option(CPM_DONT_UPDATE_MODULE_PATH "Don't update the module path to allow using find_package"
+       $ENV{CPM_DONT_UPDATE_MODULE_PATH}
+)
+option(CPM_DONT_CREATE_PACKAGE_LOCK "Don't create a package lock file in the binary path"
+       $ENV{CPM_DONT_CREATE_PACKAGE_LOCK}
+)
+option(CPM_INCLUDE_ALL_IN_PACKAGE_LOCK
+       "Add all packages added through CPM.cmake to the package lock"
+       $ENV{CPM_INCLUDE_ALL_IN_PACKAGE_LOCK}
+)
+
+set(CPM_VERSION
+    ${CURRENT_CPM_VERSION}
+    CACHE INTERNAL ""
+)
+set(CPM_DIRECTORY
+    ${CMAKE_CURRENT_LIST_DIR}
+    CACHE INTERNAL ""
+)
+set(CPM_FILE
+    ${CMAKE_CURRENT_LIST_FILE}
+    CACHE INTERNAL ""
+)
+set(CPM_PACKAGES
+    ""
+    CACHE INTERNAL ""
+)
+set(CPM_DRY_RUN
+    OFF
+    CACHE INTERNAL "Don't download or configure dependencies (for testing)"
+)
+
+if(DEFINED ENV{CPM_SOURCE_CACHE})
+  set(CPM_SOURCE_CACHE_DEFAULT $ENV{CPM_SOURCE_CACHE})
+else()
+  set(CPM_SOURCE_CACHE_DEFAULT OFF)
+endif()
+
+set(CPM_SOURCE_CACHE
+    ${CPM_SOURCE_CACHE_DEFAULT}
+    CACHE PATH "Directory to download CPM dependencies"
+)
+
+if(NOT CPM_DONT_UPDATE_MODULE_PATH)
+  set(CPM_MODULE_PATH
+      "${CMAKE_BINARY_DIR}/CPM_modules"
+      CACHE INTERNAL ""
+  )
+  # remove old modules
+  file(REMOVE_RECURSE ${CPM_MODULE_PATH})
+  file(MAKE_DIRECTORY ${CPM_MODULE_PATH})
+  # locally added CPM modules should override global packages
+  set(CMAKE_MODULE_PATH "${CPM_MODULE_PATH};${CMAKE_MODULE_PATH}")
+endif()
+
+if(NOT CPM_DONT_CREATE_PACKAGE_LOCK)
+  set(CPM_PACKAGE_LOCK_FILE
+      "${CMAKE_BINARY_DIR}/cpm-package-lock.cmake"
+      CACHE INTERNAL ""
+  )
+  file(WRITE ${CPM_PACKAGE_LOCK_FILE}
+       "# CPM Package Lock\n# This file should be committed to version control\n\n"
+  )
+endif()
 
 include(FetchContent)
 include(CMakeParseArguments)
 
+# Initialize logging prefix
 if(NOT CPM_INDENT)
-  set(CPM_INDENT "CPM:")
+  set(CPM_INDENT
+      "CPM:"
+      CACHE INTERNAL ""
+  )
 endif()
 
-function(CPM_REGISTER_PACKAGE PACKAGE VERSION)
-  LIST(APPEND CPM_PACKAGES ${CPM_ARGS_NAME})
-  set(CPM_PACKAGES ${CPM_PACKAGES} CACHE INTERNAL "")
-  CPM_SET_PACKAGE_VERSION(${PACKAGE} ${VERSION})
+function(cpm_find_package NAME VERSION)
+  string(REPLACE " " ";" EXTRA_ARGS "${ARGN}")
+  find_package(${NAME} ${VERSION} ${EXTRA_ARGS} QUIET)
+  if(${CPM_ARGS_NAME}_FOUND)
+    message(STATUS "${CPM_INDENT} using local package ${CPM_ARGS_NAME}@${VERSION}")
+    CPMRegisterPackage(${CPM_ARGS_NAME} "${VERSION}")
+    set(CPM_PACKAGE_FOUND
+        YES
+        PARENT_SCOPE
+    )
+  else()
+    set(CPM_PACKAGE_FOUND
+        NO
+        PARENT_SCOPE
+    )
+  endif()
 endfunction()
 
-function(CPM_SET_PACKAGE_VERSION PACKAGE VERSION)
-  set("CPM_PACKAGE_${PACKAGE}_VERSION" ${VERSION} CACHE INTERNAL "")
+# Create a custom FindXXX.cmake module for a CPM package This prevents `find_package(NAME)` from
+# finding the system library
+function(cpm_create_module_file Name)
+  if(NOT CPM_DONT_UPDATE_MODULE_PATH)
+    # erase any previous modules
+    file(WRITE ${CPM_MODULE_PATH}/Find${Name}.cmake
+         "include(${CPM_FILE})\n${ARGN}\nset(${Name}_FOUND TRUE)"
+    )
+  endif()
 endfunction()
 
-function(CPM_GET_PACKAGE_VERSION PACKAGE)
-  set(CPM_PACKAGE_VERSION "${CPM_PACKAGE_${PACKAGE}_VERSION}" PARENT_SCOPE)
-endfunction()
+# Find a package locally or fallback to CPMAddPackage
+function(CPMFindPackage)
+  set(oneValueArgs NAME VERSION GIT_TAG FIND_PACKAGE_ARGUMENTS)
 
-function(CPM_PARSE_OPTION OPTION)
-  string(REGEX MATCH "^[^ ]+" OPTION_KEY ${OPTION})
-  string(LENGTH ${OPTION_KEY} OPTION_KEY_LENGTH)
-  math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
-  string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
-  set(OPTION_KEY "${OPTION_KEY}" PARENT_SCOPE)
-  set(OPTION_VALUE "${OPTION_VALUE}" PARENT_SCOPE)
-endfunction()
+  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "" ${ARGN})
 
-function(CPMAddPackage)
-    
-  set(oneValueArgs
-    NAME
-    VERSION
-    GIT_TAG
-  )
-
-  set(multiValueArgs
-    OPTIONS
-  )
-
-  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
-
-  if (CPM_ARGS_VERSION AND NOT CPM_ARGS_OPTIONS AND NOT ${CPM_REMOTE_PACKAGES_ONLY})
-    find_package(${CPM_ARGS_NAME} ${CPM_ARGS_VERSION} QUIET)
-
-    if(${CPM_PACKAGE_FOUND})
-      message(STATUS "CPM: adding local package ${CPM_ARGS_NAME}@${CPM_ARGS_VERSION}")
-      set_target_properties(${CPM_ARGS_NAME} 
-        PROPERTIES
-          IMPORTED_GLOBAL True
-      )
-      return()
+  if(NOT DEFINED CPM_ARGS_VERSION)
+    if(DEFINED CPM_ARGS_GIT_TAG)
+      cpm_get_version_from_git_tag("${CPM_ARGS_GIT_TAG}" CPM_ARGS_VERSION)
     endif()
   endif()
 
-  if (NOT CPM_ARGS_VERSION)
-    set(CPM_ARGS_VERSION 0)
-  endif()
-
-  if (NOT CPM_ARGS_GIT_TAG)
-    set(CPM_ARGS_GIT_TAG v${CPM_ARGS_VERSION})
-  endif()
-
-  if (${CPM_ARGS_NAME} IN_LIST CPM_PACKAGES)
-    CPM_GET_PACKAGE_VERSION(${CPM_ARGS_NAME})
-    if(${CPM_PACKAGE_VERSION} VERSION_LESS ${CPM_ARGS_VERSION})
-      message(WARNING "${CPM_INDENT} newer package ${CPM_ARGS_NAME} requested (${CPM_ARGS_VERSION}, currently using ${CPM_PACKAGE_VERSION})")
-    endif()
-    if (CPM_ARGS_OPTIONS)
-      foreach(OPTION ${CPM_ARGS_OPTIONS})
-        CPM_PARSE_OPTION(${OPTION})
-        if(NOT "${${OPTION_KEY}}" STREQUAL ${OPTION_VALUE})
-          message(WARNING "${CPM_INDENT} ignoring package option for ${CPM_ARGS_NAME}: ${OPTION_KEY} = ${OPTION_VALUE} (${${OPTION_KEY}})")
-        else()
-          message(STATUS "${CPM_INDENT} NOT ignoring package option for ${CPM_ARGS_NAME}: ${OPTION_KEY} = ${OPTION_VALUE} (${${OPTION_KEY}})")
-        endif()
-      endforeach()
-    endif()
-    CPM_FETCH_PACKAGE(${CPM_ARGS_NAME})
+  if(CPM_DOWNLOAD_ALL)
+    CPMAddPackage(${ARGN})
+    cpm_export_variables(${CPM_ARGS_NAME})
     return()
   endif()
 
-  CPM_REGISTER_PACKAGE(${CPM_ARGS_NAME} ${CPM_ARGS_VERSION})
+  cpm_check_if_package_already_added(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" "${CPM_ARGS_OPTIONS}")
+  if(CPM_PACKAGE_ALREADY_ADDED)
+    cpm_export_variables(${CPM_ARGS_NAME})
+    return()
+  endif()
 
-  if (CPM_ARGS_OPTIONS)
+  cpm_find_package(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" ${CPM_ARGS_FIND_PACKAGE_ARGUMENTS})
+
+  if(NOT CPM_PACKAGE_FOUND)
+    CPMAddPackage(${ARGN})
+    cpm_export_variables(${CPM_ARGS_NAME})
+  endif()
+
+endfunction()
+
+# checks if a package has been added before
+function(cpm_check_if_package_already_added CPM_ARGS_NAME CPM_ARGS_VERSION CPM_ARGS_OPTIONS)
+  if("${CPM_ARGS_NAME}" IN_LIST CPM_PACKAGES)
+    CPMGetPackageVersion(${CPM_ARGS_NAME} CPM_PACKAGE_VERSION)
+    if("${CPM_PACKAGE_VERSION}" VERSION_LESS "${CPM_ARGS_VERSION}")
+      message(
+        WARNING
+          "${CPM_INDENT} requires a newer version of ${CPM_ARGS_NAME} (${CPM_ARGS_VERSION}) than currently included (${CPM_PACKAGE_VERSION})."
+      )
+    endif()
+    if(CPM_ARGS_OPTIONS)
+      foreach(OPTION ${CPM_ARGS_OPTIONS})
+        cpm_parse_option(${OPTION})
+        if(NOT "${${OPTION_KEY}}" STREQUAL "${OPTION_VALUE}")
+          message(
+            WARNING
+              "${CPM_INDENT} ignoring package option for ${CPM_ARGS_NAME}: ${OPTION_KEY} = ${OPTION_VALUE} (${${OPTION_KEY}})"
+          )
+        endif()
+      endforeach()
+    endif()
+    cpm_get_fetch_properties(${CPM_ARGS_NAME})
+    set(${CPM_ARGS_NAME}_ADDED NO)
+    set(CPM_PACKAGE_ALREADY_ADDED
+        YES
+        PARENT_SCOPE
+    )
+    cpm_export_variables(${CPM_ARGS_NAME})
+  else()
+    set(CPM_PACKAGE_ALREADY_ADDED
+        NO
+        PARENT_SCOPE
+    )
+  endif()
+endfunction()
+
+# Download and add a package from source
+function(CPMAddPackage)
+
+  set(oneValueArgs
+      NAME
+      FORCE
+      VERSION
+      GIT_TAG
+      DOWNLOAD_ONLY
+      GITHUB_REPOSITORY
+      GITLAB_REPOSITORY
+      GIT_REPOSITORY
+      SOURCE_DIR
+      DOWNLOAD_COMMAND
+      FIND_PACKAGE_ARGUMENTS
+      NO_CACHE
+      GIT_SHALLOW
+      EXCLUDE_FROM_ALL
+  )
+
+  set(multiValueArgs OPTIONS)
+
+  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" "${ARGN}")
+
+  # Set default values for arguments
+
+  if(NOT DEFINED CPM_ARGS_VERSION)
+    if(DEFINED CPM_ARGS_GIT_TAG)
+      cpm_get_version_from_git_tag("${CPM_ARGS_GIT_TAG}" CPM_ARGS_VERSION)
+    endif()
+  endif()
+
+  if(CPM_ARGS_DOWNLOAD_ONLY)
+    set(DOWNLOAD_ONLY ${CPM_ARGS_DOWNLOAD_ONLY})
+  else()
+    set(DOWNLOAD_ONLY NO)
+  endif()
+
+  if(DEFINED CPM_ARGS_GITHUB_REPOSITORY)
+    set(CPM_ARGS_GIT_REPOSITORY "https://github.com/${CPM_ARGS_GITHUB_REPOSITORY}.git")
+  endif()
+
+  if(DEFINED CPM_ARGS_GITLAB_REPOSITORY)
+    set(CPM_ARGS_GIT_REPOSITORY "https://gitlab.com/${CPM_ARGS_GITLAB_REPOSITORY}.git")
+  endif()
+
+  if(DEFINED CPM_ARGS_GIT_REPOSITORY)
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_REPOSITORY ${CPM_ARGS_GIT_REPOSITORY})
+    if(NOT DEFINED CPM_ARGS_GIT_TAG)
+      set(CPM_ARGS_GIT_TAG v${CPM_ARGS_VERSION})
+    endif()
+  endif()
+
+  set(CPM_SKIP_FETCH FALSE)
+
+  if(DEFINED CPM_ARGS_GIT_TAG)
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_TAG ${CPM_ARGS_GIT_TAG})
+    # If GIT_SHALLOW is explicitly specified, honor the value.
+    if(DEFINED CPM_ARGS_GIT_SHALLOW)
+      list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_SHALLOW ${CPM_ARGS_GIT_SHALLOW})
+    endif()
+  endif()
+
+  # Check if package has been added before
+  cpm_check_if_package_already_added(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" "${CPM_ARGS_OPTIONS}")
+  if(CPM_PACKAGE_ALREADY_ADDED)
+    cpm_export_variables(${CPM_ARGS_NAME})
+    return()
+  endif()
+
+  # Check for manual overrides
+  if(NOT CPM_ARGS_FORCE AND NOT "${CPM_${CPM_ARGS_NAME}_SOURCE}" STREQUAL "")
+    set(PACKAGE_SOURCE ${CPM_${CPM_ARGS_NAME}_SOURCE})
+    set(CPM_${CPM_ARGS_NAME}_SOURCE "")
+    CPMAddPackage(
+      NAME ${CPM_ARGS_NAME}
+      SOURCE_DIR ${PACKAGE_SOURCE}
+      FORCE True
+      OPTIONS ${CPM_ARGS_OPTIONS}
+    )
+    cpm_export_variables(${CPM_ARGS_NAME})
+    return()
+  endif()
+
+  # Check for available declaration
+  if(NOT CPM_ARGS_FORCE AND NOT "${CPM_DECLARATION_${CPM_ARGS_NAME}}" STREQUAL "")
+    set(declaration ${CPM_DECLARATION_${CPM_ARGS_NAME}})
+    set(CPM_DECLARATION_${CPM_ARGS_NAME} "")
+    CPMAddPackage(${declaration})
+    cpm_export_variables(${CPM_ARGS_NAME})
+    # checking again to ensure version and option compatibility
+    cpm_check_if_package_already_added(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" "${CPM_ARGS_OPTIONS}")
+    return()
+  endif()
+
+  if(CPM_USE_LOCAL_PACKAGES OR CPM_LOCAL_PACKAGES_ONLY)
+    cpm_find_package(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" ${CPM_ARGS_FIND_PACKAGE_ARGUMENTS})
+
+    if(CPM_PACKAGE_FOUND)
+      cpm_export_variables(${CPM_ARGS_NAME})
+      return()
+    endif()
+
+    if(CPM_LOCAL_PACKAGES_ONLY)
+      message(
+        SEND_ERROR
+          "CPM: ${CPM_ARGS_NAME} not found via find_package(${CPM_ARGS_NAME} ${CPM_ARGS_VERSION})"
+      )
+    endif()
+  endif()
+
+  CPMRegisterPackage("${CPM_ARGS_NAME}" "${CPM_ARGS_VERSION}")
+
+  if(CPM_ARGS_OPTIONS)
     foreach(OPTION ${CPM_ARGS_OPTIONS})
-      CPM_PARSE_OPTION(${OPTION})
-      set(${OPTION_KEY} ${OPTION_VALUE} CACHE INTERNAL "")
+      cpm_parse_option(${OPTION})
+      set(${OPTION_KEY}
+          ${OPTION_VALUE}
+          CACHE INTERNAL ""
+      )
     endforeach()
   endif()
 
-  CPM_DECLARE_PACKAGE(${CPM_ARGS_NAME} ${CPM_ARGS_VERSION} ${CPM_ARGS_GIT_TAG} "${CPM_ARGS_UNPARSED_ARGUMENTS}")
-  CPM_FETCH_PACKAGE(${CPM_ARGS_NAME})
+  if(DEFINED CPM_ARGS_GIT_TAG)
+    set(PACKAGE_INFO "${CPM_ARGS_GIT_TAG}")
+  elseif(DEFINED CPM_ARGS_SOURCE_DIR)
+    set(PACKAGE_INFO "${CPM_ARGS_SOURCE_DIR}")
+  else()
+    set(PACKAGE_INFO "${CPM_ARGS_VERSION}")
+  endif()
+
+  if(DEFINED CPM_ARGS_DOWNLOAD_COMMAND)
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS DOWNLOAD_COMMAND ${CPM_ARGS_DOWNLOAD_COMMAND})
+  elseif(DEFINED CPM_ARGS_SOURCE_DIR)
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS SOURCE_DIR ${CPM_ARGS_SOURCE_DIR})
+  elseif(CPM_SOURCE_CACHE AND NOT CPM_ARGS_NO_CACHE)
+    string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
+    set(origin_parameters ${CPM_ARGS_UNPARSED_ARGUMENTS})
+    list(SORT origin_parameters)
+    string(SHA1 origin_hash "${origin_parameters}")
+    set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${origin_hash})
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS SOURCE_DIR ${download_directory})
+    if(EXISTS ${download_directory})
+      # avoid FetchContent modules to improve performance
+      set(${CPM_ARGS_NAME}_BINARY_DIR ${CMAKE_BINARY_DIR}/_deps/${lower_case_name}-build)
+      set(${CPM_ARGS_NAME}_ADDED YES)
+      set(${CPM_ARGS_NAME}_SOURCE_DIR ${download_directory})
+      if(NOT CPM_ARGS_DOWNLOAD_ONLY AND EXISTS ${download_directory}/CMakeLists.txt)
+        cpm_add_subdirectory(
+          ${download_directory} ${${CPM_ARGS_NAME}_BINARY_DIR} "${CPM_ARGS_EXCLUDE_FROM_ALL}"
+        )
+      endif()
+      set(CPM_SKIP_FETCH TRUE)
+      set(PACKAGE_INFO "${PACKAGE_INFO} at ${download_directory}")
+    else()
+      # Enable shallow clone when GIT_TAG is not a commit hash. Our guess may not be accurate, but
+      # it should guarantee no commit hash get mis-detected.
+      if(NOT DEFINED CPM_ARGS_GIT_SHALLOW)
+        cpm_is_git_tag_commit_hash("${CPM_ARGS_GIT_TAG}" IS_HASH)
+        if(NOT ${IS_HASH})
+          list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_SHALLOW TRUE)
+        endif()
+      endif()
+
+      # remove timestamps so CMake will re-download the dependency
+      file(REMOVE_RECURSE ${CMAKE_BINARY_DIR}/_deps/${lower_case_name}-subbuild)
+      set(PACKAGE_INFO "${PACKAGE_INFO} to ${download_directory}")
+    endif()
+  endif()
+
+  cpm_create_module_file(${CPM_ARGS_NAME} "CPMAddPackage(${ARGN})")
+
+  if(CPM_PACKAGE_LOCK_ENABLED)
+    if((CPM_ARGS_VERSION AND NOT CPM_ARGS_SOURCE_DIR) OR CPM_INCLUDE_ALL_IN_PACKAGE_LOCK)
+      cpm_add_to_package_lock(${CPM_ARGS_NAME} "${ARGN}")
+    elseif(CPM_ARGS_SOURCE_DIR)
+      cpm_add_comment_to_package_lock(${CPM_ARGS_NAME} "local directory")
+    else()
+      cpm_add_comment_to_package_lock(${CPM_ARGS_NAME} "${ARGN}")
+    endif()
+  endif()
+
+  message(
+    STATUS "${CPM_INDENT} adding package ${CPM_ARGS_NAME}@${CPM_ARGS_VERSION} (${PACKAGE_INFO})"
+  )
+
+  if(NOT CPM_SKIP_FETCH)
+    cpm_declare_fetch(
+      "${CPM_ARGS_NAME}" "${CPM_ARGS_VERSION}" "${PACKAGE_INFO}" "${CPM_ARGS_UNPARSED_ARGUMENTS}"
+    )
+    cpm_fetch_package("${CPM_ARGS_NAME}" "${DOWNLOAD_ONLY}" "${CPM_ARGS_EXCLUDE_FROM_ALL}")
+    cpm_get_fetch_properties("${CPM_ARGS_NAME}")
+  endif()
+
+  set(${CPM_ARGS_NAME}_ADDED YES)
+  cpm_export_variables("${CPM_ARGS_NAME}")
 endfunction()
 
-function (CPM_DECLARE_PACKAGE PACKAGE VERSION GIT_TAG)
-  message(STATUS "${CPM_INDENT} adding package ${PACKAGE}@${VERSION} (${GIT_TAG})")
+# Fetch a previously declared package
+macro(CPMGetPackage Name)
+  if(DEFINED "CPM_DECLARATION_${Name}")
+    CPMAddPackage(NAME ${Name})
+  else()
+    message(SEND_ERROR "Cannot retrieve package ${Name}: no declaration available")
+  endif()
+endmacro()
 
-  FetchContent_Declare(
-    ${PACKAGE}
-    GIT_TAG ${GIT_TAG}
-    ${ARGN}
+# export variables available to the caller to the parent scope expects ${CPM_ARGS_NAME} to be set
+macro(cpm_export_variables name)
+  set(${name}_SOURCE_DIR
+      "${${name}_SOURCE_DIR}"
+      PARENT_SCOPE
+  )
+  set(${name}_BINARY_DIR
+      "${${name}_BINARY_DIR}"
+      PARENT_SCOPE
+  )
+  set(${name}_ADDED
+      "${${name}_ADDED}"
+      PARENT_SCOPE
+  )
+endmacro()
+
+# declares a package, so that any call to CPMAddPackage for the package name will use these
+# arguments instead. Previous declarations will not be overriden.
+macro(CPMDeclarePackage Name)
+  if(NOT DEFINED "CPM_DECLARATION_${Name}")
+    set("CPM_DECLARATION_${Name}" "${ARGN}")
+  endif()
+endmacro()
+
+function(cpm_add_to_package_lock Name)
+  if(NOT CPM_DONT_CREATE_PACKAGE_LOCK)
+    cpm_prettify_package_arguments(PRETTY_ARGN false ${ARGN})
+    file(APPEND ${CPM_PACKAGE_LOCK_FILE} "# ${Name}\nCPMDeclarePackage(${Name}\n${PRETTY_ARGN})\n")
+  endif()
+endfunction()
+
+function(cpm_add_comment_to_package_lock Name)
+  if(NOT CPM_DONT_CREATE_PACKAGE_LOCK)
+    cpm_prettify_package_arguments(PRETTY_ARGN true ${ARGN})
+    file(APPEND ${CPM_PACKAGE_LOCK_FILE}
+         "# ${Name} (unversioned)\n# CPMDeclarePackage(${Name}\n${PRETTY_ARGN}#)\n"
+    )
+  endif()
+endfunction()
+
+# includes the package lock file if it exists and creates a target `cpm-write-package-lock` to
+# update it
+macro(CPMUsePackageLock file)
+  if(NOT CPM_DONT_CREATE_PACKAGE_LOCK)
+    get_filename_component(CPM_ABSOLUTE_PACKAGE_LOCK_PATH ${file} ABSOLUTE)
+    if(EXISTS ${CPM_ABSOLUTE_PACKAGE_LOCK_PATH})
+      include(${CPM_ABSOLUTE_PACKAGE_LOCK_PATH})
+    endif()
+    if(NOT TARGET cpm-update-package-lock)
+      add_custom_target(
+        cpm-update-package-lock COMMAND ${CMAKE_COMMAND} -E copy ${CPM_PACKAGE_LOCK_FILE}
+                                        ${CPM_ABSOLUTE_PACKAGE_LOCK_PATH}
+      )
+    endif()
+    set(CPM_PACKAGE_LOCK_ENABLED true)
+  endif()
+endmacro()
+
+# registers a package that has been added to CPM
+function(CPMRegisterPackage PACKAGE VERSION)
+  list(APPEND CPM_PACKAGES ${PACKAGE})
+  set(CPM_PACKAGES
+      ${CPM_PACKAGES}
+      CACHE INTERNAL ""
+  )
+  set("CPM_PACKAGE_${PACKAGE}_VERSION"
+      ${VERSION}
+      CACHE INTERNAL ""
   )
 endfunction()
 
-function (CPM_FETCH_PACKAGE PACKAGE)  
-  set(CPM_OLD_INDENT "${CPM_INDENT}")
-  set(CPM_INDENT "${CPM_INDENT} ${PACKAGE}:")
-  FetchContent_MakeAvailable(${PACKAGE})
-  set(CPM_INDENT "${CPM_OLD_INDENT}")
-endfunction()
+# retrieve the current version of the package to ${OUTPUT}
+function(CPMGetPackageVersion PACKAGE OUTPUT)
+  set(${OUTPUT}
+      "${CPM_PACKAGE_${PACKAGE}_VERSION}"
+      PARENT_SCOPE
+  )
+endfunction()
+
+# declares a package in FetchContent_Declare
+function(cpm_declare_fetch PACKAGE VERSION INFO)
+  if(${CPM_DRY_RUN})
+    message(STATUS "${CPM_INDENT} package not declared (dry run)")
+    return()
+  endif()
+
+  FetchContent_Declare(${PACKAGE} ${ARGN})
+endfunction()
+
+# returns properties for a package previously defined by cpm_declare_fetch
+function(cpm_get_fetch_properties PACKAGE)
+  if(${CPM_DRY_RUN})
+    return()
+  endif()
+  FetchContent_GetProperties(${PACKAGE})
+  string(TOLOWER ${PACKAGE} lpackage)
+  set(${PACKAGE}_SOURCE_DIR
+      "${${lpackage}_SOURCE_DIR}"
+      PARENT_SCOPE
+  )
+  set(${PACKAGE}_BINARY_DIR
+      "${${lpackage}_BINARY_DIR}"
+      PARENT_SCOPE
+  )
+endfunction()
+
+function(cpm_add_subdirectory SOURCE_DIR BINARY_DIR EXCLUDE)
+  if(EXCLUDE)
+    set(addSubdirectoryExtraArgs EXCLUDE_FROM_ALL)
+  else()
+    set(addSubdirectoryExtraArgs "")
+  endif()
+  add_subdirectory(${SOURCE_DIR} ${BINARY_DIR} ${addSubdirectoryExtraArgs})
+endfunction()
+
+# downloads a previously declared package via FetchContent
+function(cpm_fetch_package PACKAGE DOWNLOAD_ONLY EXCLUDE)
+  if(${CPM_DRY_RUN})
+    message(STATUS "${CPM_INDENT} package ${PACKAGE} not fetched (dry run)")
+    return()
+  endif()
+
+  FetchContent_GetProperties(${PACKAGE})
+  string(TOLOWER "${PACKAGE}" lower_case_name)
+
+  if(NOT ${lower_case_name}_POPULATED)
+    FetchContent_Populate(${PACKAGE})
+    if(NOT DOWNLOAD_ONLY AND EXISTS ${${lower_case_name}_SOURCE_DIR}/CMakeLists.txt)
+      set(CPM_OLD_INDENT "${CPM_INDENT}")
+      set(CPM_INDENT "${CPM_INDENT} ${PACKAGE}:")
+      cpm_add_subdirectory(
+        ${${lower_case_name}_SOURCE_DIR} ${${lower_case_name}_BINARY_DIR} "${EXCLUDE}"
+      )
+      set(CPM_INDENT "${CPM_OLD_INDENT}")
+    endif()
+  endif()
+endfunction()
+
+# splits a package option
+function(cpm_parse_option OPTION)
+  string(REGEX MATCH "^[^ ]+" OPTION_KEY ${OPTION})
+  string(LENGTH ${OPTION} OPTION_LENGTH)
+  string(LENGTH ${OPTION_KEY} OPTION_KEY_LENGTH)
+  if(OPTION_KEY_LENGTH STREQUAL OPTION_LENGTH)
+    # no value for key provided, assume user wants to set option to "ON"
+    set(OPTION_VALUE "ON")
+  else()
+    math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
+    string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
+  endif()
+  set(OPTION_KEY
+      "${OPTION_KEY}"
+      PARENT_SCOPE
+  )
+  set(OPTION_VALUE
+      "${OPTION_VALUE}"
+      PARENT_SCOPE
+  )
+endfunction()
+
+# guesses the package version from a git tag
+function(cpm_get_version_from_git_tag GIT_TAG RESULT)
+  string(LENGTH ${GIT_TAG} length)
+  if(length EQUAL 40)
+    # GIT_TAG is probably a git hash
+    set(${RESULT}
+        0
+        PARENT_SCOPE
+    )
+  else()
+    string(REGEX MATCH "v?([0123456789.]*).*" _ ${GIT_TAG})
+    set(${RESULT}
+        ${CMAKE_MATCH_1}
+        PARENT_SCOPE
+    )
+  endif()
+endfunction()
+
+# guesses if the git tag is a commit hash or an actual tag or a branch nane.
+function(cpm_is_git_tag_commit_hash GIT_TAG RESULT)
+  string(LENGTH "${GIT_TAG}" length)
+  # full hash has 40 characters, and short hash has at least 7 characters.
+  if(length LESS 7 OR length GREATER 40)
+    set(${RESULT}
+        0
+        PARENT_SCOPE
+    )
+  else()
+    if(${GIT_TAG} MATCHES "^[a-fA-F0-9]+$")
+      set(${RESULT}
+          1
+          PARENT_SCOPE
+      )
+    else()
+      set(${RESULT}
+          0
+          PARENT_SCOPE
+      )
+    endif()
+  endif()
+endfunction()
+
+function(cpm_prettify_package_arguments OUT_VAR IS_IN_COMMENT)
+  set(oneValueArgs
+      NAME
+      FORCE
+      VERSION
+      GIT_TAG
+      DOWNLOAD_ONLY
+      GITHUB_REPOSITORY
+      GITLAB_REPOSITORY
+      GIT_REPOSITORY
+      SOURCE_DIR
+      DOWNLOAD_COMMAND
+      FIND_PACKAGE_ARGUMENTS
+      NO_CACHE
+      GIT_SHALLOW
+  )
+  set(multiValueArgs OPTIONS)
+  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+  foreach(oneArgName ${oneValueArgs})
+    if(DEFINED CPM_ARGS_${oneArgName})
+      if(${IS_IN_COMMENT})
+        string(APPEND PRETTY_OUT_VAR "#")
+      endif()
+      if(${oneArgName} STREQUAL "SOURCE_DIR")
+        string(REPLACE ${CMAKE_SOURCE_DIR} "\${CMAKE_SOURCE_DIR}" CPM_ARGS_${oneArgName}
+                       ${CPM_ARGS_${oneArgName}}
+        )
+      endif()
+      string(APPEND PRETTY_OUT_VAR "  ${oneArgName} ${CPM_ARGS_${oneArgName}}\n")
+    endif()
+  endforeach()
+  foreach(multiArgName ${multiValueArgs})
+    if(DEFINED CPM_ARGS_${multiArgName})
+      if(${IS_IN_COMMENT})
+        string(APPEND PRETTY_OUT_VAR "#")
+      endif()
+      string(APPEND PRETTY_OUT_VAR "  ${multiArgName}\n")
+      foreach(singleOption ${CPM_ARGS_${multiArgName}})
+        if(${IS_IN_COMMENT})
+          string(APPEND PRETTY_OUT_VAR "#")
+        endif()
+        string(APPEND PRETTY_OUT_VAR "    \"${singleOption}\"\n")
+      endforeach()
+    endif()
+  endforeach()
+
+  if(NOT "${CPM_ARGS_UNPARSED_ARGUMENTS}" STREQUAL "")
+    if(${IS_IN_COMMENT})
+      string(APPEND PRETTY_OUT_VAR "#")
+    endif()
+    string(APPEND PRETTY_OUT_VAR " ")
+    foreach(CPM_ARGS_UNPARSED_ARGUMENT ${CPM_ARGS_UNPARSED_ARGUMENTS})
+      string(APPEND PRETTY_OUT_VAR " ${CPM_ARGS_UNPARSED_ARGUMENT}")
+    endforeach()
+    string(APPEND PRETTY_OUT_VAR "\n")
+  endif()
+
+  set(${OUT_VAR}
+      ${PRETTY_OUT_VAR}
+      PARENT_SCOPE
+  )
+
+endfunction()

cmake/get_cpm.cmake

@@ -0,0 +1,21 @@
+set(CPM_DOWNLOAD_VERSION 1.0.0-development-version)
+
+if(CPM_SOURCE_CACHE)
+  # Expand relative path. This is important if the provided path contains a tilde (~)
+  get_filename_component(CPM_SOURCE_CACHE ${CPM_SOURCE_CACHE} ABSOLUTE)
+  set(CPM_DOWNLOAD_LOCATION "${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()
+
+if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
+  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
+       ${CPM_DOWNLOAD_LOCATION}
+  )
+endif()
+
+include(${CPM_DOWNLOAD_LOCATION})

cmake/testing.cmake

@@ -0,0 +1,53 @@
+function(ASSERT_EQUAL)
+  if(NOT ARGC EQUAL 2)
+    message(FATAL_ERROR "assertion failed: invalid argument count: ${ARGC}")
+  endif()
+
+  if(NOT ${ARGV0} STREQUAL ${ARGV1})
+    message(FATAL_ERROR "assertion failed: '${ARGV0}' != '${ARGV1}'")
+  else()
+    message(STATUS "test passed: '${ARGV0}' == '${ARGV1}'")
+  endif()
+endfunction()
+
+function(ASSERT_EMPTY)
+  if(NOT ARGC EQUAL 0)
+    message(FATAL_ERROR "assertion failed: input ${ARGC} not empty: '${ARGV}'")
+  endif()
+endfunction()
+
+function(ASSERT_DEFINED KEY)
+  if(DEFINED ${KEY})
+    message(STATUS "test passed: '${KEY}' is defined")
+  else()
+    message(FATAL_ERROR "assertion failed: '${KEY}' is not defiend")
+  endif()
+endfunction()
+
+function(ASSERT_TRUTHY KEY)
+  if(${${KEY}})
+    message(STATUS "test passed: '${KEY}' is set truthy")
+  else()
+    message(FATAL_ERROR "assertion failed: value of '${KEY}' is not true (${${KEY}})")
+  endif()
+endfunction()
+
+function(ASSERTION_FAILED)
+  message(FATAL_ERROR "assertion failed: ${ARGN}")
+endfunction()
+
+function(ASSERT_EXISTS file)
+  if(EXISTS ${file})
+    message(STATUS "test passed: '${file}' exists")
+  else()
+    message(FATAL_ERROR "assertion failed: file ${file} does not exist")
+  endif()
+endfunction()
+
+function(ASSERT_NOT_EXISTS file)
+  if(NOT EXISTS ${file})
+    message(STATUS "test passed: '${file}' does not exist")
+  else()
+    message(FATAL_ERROR "assertion failed: file ${file} exists")
+  endif()
+endfunction()

examples/asio-standalone/CMakeLists.txt

@@ -0,0 +1,68 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleASIOStandalone)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+find_package(Threads REQUIRED)
+
+CPMAddPackage(
+  NAME asio
+  VERSION 1.18.1
+  GITHUB_REPOSITORY chriskohlhoff/asio
+  GIT_TAG asio-1-18-1 # asio uses non-standard version tag, we must specify GIT_TAG
+)
+
+# ASIO doesn't use CMake, we have to configure it manually. Extra notes for using on Windows:
+#
+# 1) If _WIN32_WINNT is not set, ASIO assumes _WIN32_WINNT=0x0501, i.e. Windows XP target, which is
+# definitely not the platform which most users target.
+#
+# 2) WIN32_LEAN_AND_MEAN is defined to make Winsock2 work.
+if(asio_ADDED)
+  add_library(asio INTERFACE)
+
+  target_include_directories(asio SYSTEM INTERFACE ${asio_SOURCE_DIR}/asio/include)
+
+  target_compile_definitions(asio INTERFACE ASIO_STANDALONE ASIO_NO_DEPRECATED)
+
+  target_link_libraries(asio INTERFACE Threads::Threads)
+
+  if(WIN32)
+    # macro see @ https://stackoverflow.com/a/40217291/1746503
+    macro(get_win32_winnt version)
+      if(CMAKE_SYSTEM_VERSION)
+        set(ver ${CMAKE_SYSTEM_VERSION})
+        string(REGEX MATCH "^([0-9]+).([0-9])" ver ${ver})
+        string(REGEX MATCH "^([0-9]+)" verMajor ${ver})
+        # Check for Windows 10, b/c we'll need to convert to hex 'A'.
+        if("${verMajor}" MATCHES "10")
+          set(verMajor "A")
+          string(REGEX REPLACE "^([0-9]+)" ${verMajor} ver ${ver})
+        endif("${verMajor}" MATCHES "10")
+        # Remove all remaining '.' characters.
+        string(REPLACE "." "" ver ${ver})
+        # Prepend each digit with a zero.
+        string(REGEX REPLACE "([0-9A-Z])" "0\\1" ver ${ver})
+        set(${version} "0x${ver}")
+      endif()
+    endmacro()
+
+    if(NOT DEFINED _WIN32_WINNT)
+      get_win32_winnt(ver)
+      set(_WIN32_WINNT ${ver})
+    endif()
+
+    message(STATUS "Set _WIN32_WINNET=${_WIN32_WINNT}")
+
+    target_compile_definitions(asio INTERFACE _WIN32_WINNT=${_WIN32_WINNT} WIN32_LEAN_AND_MEAN)
+  endif()
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMExampleASIOStandalone main.cpp)
+target_link_libraries(CPMExampleASIOStandalone asio)
+target_compile_features(CPMExampleASIOStandalone PRIVATE cxx_std_11)

examples/asio-standalone/main.cpp

@@ -0,0 +1,93 @@
+//
+// async_tcp_echo_server.cpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#include <cstdlib>
+#include <iostream>
+#include <memory>
+#include <utility>
+
+#include "asio.hpp"
+
+// An asynchronous tcp echo server.
+// See https://think-async.com/Asio/asio-1.16.1/src/examples/cpp11/echo/async_tcp_echo_server.cpp
+
+using asio::ip::tcp;
+
+class session : public std::enable_shared_from_this<session> {
+public:
+  session(tcp::socket socket) : socket_(std::move(socket)) {}
+
+  void start() { do_read(); }
+
+private:
+  void do_read() {
+    auto self(shared_from_this());
+    socket_.async_read_some(asio::buffer(data_, max_length),
+                            [this, self](std::error_code ec, std::size_t length) {
+                              if (!ec) {
+                                do_write(length);
+                              }
+                            });
+  }
+
+  void do_write(std::size_t length) {
+    auto self(shared_from_this());
+    asio::async_write(socket_, asio::buffer(data_, length),
+                      [this, self](std::error_code ec, std::size_t /*length*/) {
+                        if (!ec) {
+                          do_read();
+                        }
+                      });
+  }
+
+  tcp::socket socket_;
+  enum { max_length = 1024 };
+  char data_[max_length];
+};
+
+class server {
+public:
+  server(asio::io_context& io_context, short port)
+      : acceptor_(io_context, tcp::endpoint(tcp::v4(), port)) {
+    do_accept();
+  }
+
+private:
+  void do_accept() {
+    acceptor_.async_accept([this](std::error_code ec, tcp::socket socket) {
+      if (!ec) {
+        std::make_shared<session>(std::move(socket))->start();
+      }
+
+      do_accept();
+    });
+  }
+
+  tcp::acceptor acceptor_;
+};
+
+int main(int argc, char* argv[]) {
+  try {
+    if (argc != 2) {
+      std::cerr << "Usage: async_tcp_echo_server <port>\n";
+      return 1;
+    }
+
+    asio::io_context io_context;
+
+    server s(io_context, std::atoi(argv[1]));
+
+    io_context.run();
+  } catch (std::exception& e) {
+    std::cerr << "Exception: " << e.what() << "\n";
+  }
+
+  return 0;
+}

examples/benchmark/CMakeLists.txt

@@ -0,0 +1,31 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleBenchmark)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME fibonacci
+  GITLAB_REPOSITORY TheLartians/Fibonacci
+  VERSION 2.0
+)
+
+CPMAddPackage(
+  NAME benchmark
+  GITHUB_REPOSITORY google/benchmark
+  VERSION 1.5.2
+  OPTIONS "BENCHMARK_ENABLE_TESTING Off"
+)
+
+if(benchmark_ADDED)
+  # Don't use C++14 because it doesn't work in some configurations.
+  set_target_properties(benchmark PROPERTIES CXX_STANDARD 11)
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMExampleBenchmark "main.cpp")
+target_link_libraries(CPMExampleBenchmark fibonacci benchmark)
+target_compile_features(CPMExampleBenchmark PRIVATE cxx_std_17)

examples/benchmark/main.cpp

@@ -0,0 +1,35 @@
+#include <benchmark/benchmark.h>
+#include <fibonacci.h>
+
+#include <algorithm>
+#include <random>
+#include <vector>
+
+std::vector<unsigned> createTestNumbers() {
+  std::vector<unsigned> v;
+  for (int i = 0; i < 25; ++i) v.emplace_back(i);
+  std::random_device rd;
+  std::mt19937 g(rd());
+  std::shuffle(v.begin(), v.end(), g);
+  return v;
+}
+
+void fibonacci(benchmark::State& state) {
+  auto numbers = createTestNumbers();
+  for (auto _ : state) {
+    for (auto v : numbers) benchmark::DoNotOptimize(fibonacci(v));
+  }
+}
+
+BENCHMARK(fibonacci);
+
+void fastFibonacci(benchmark::State& state) {
+  auto numbers = createTestNumbers();
+  for (auto _ : state) {
+    for (auto v : numbers) benchmark::DoNotOptimize(fastFibonacci(v));
+  }
+}
+
+BENCHMARK(fastFibonacci);
+
+BENCHMARK_MAIN();

examples/boost/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleBoost)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleBoost main.cpp)
+target_compile_features(CPMExampleBoost PRIVATE cxx_std_17)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMFindPackage(
+  NAME Boost
+  GITHUB_REPOSITORY Orphis/boost-cmake
+  VERSION 1.67.0
+  FIND_PACKAGE_ARGUMENTS "COMPONENTS system"
+)
+
+find_package(Threads REQUIRED)
+
+target_link_libraries(CPMExampleBoost PRIVATE Boost::system Threads::Threads)

examples/boost/main.cpp

@@ -0,0 +1,26 @@
+//
+// timer.cpp
+// ~~~~~~~~~
+//
+// Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#include <boost/asio.hpp>
+#include <boost/date_time/posix_time/posix_time.hpp>
+#include <iostream>
+
+void print(const boost::system::error_code& /*e*/) { std::cout << "Hello, world!" << std::endl; }
+
+int main() {
+  boost::asio::io_service io;
+
+  boost::asio::deadline_timer t(io, boost::posix_time::seconds(1));
+  t.async_wait(&print);
+
+  io.run();
+
+  return 0;
+}

examples/build_all.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python3
+
+import os
+
+from pathlib import Path
+from subprocess import PIPE, run
+
+examples = [
+  x for x in Path(__file__).parent.iterdir() if x.is_dir() and (x / 'CMakeLists.txt').exists()
+]
+
+assert(len(examples) > 0)
+
+
+def runCommand(command):
+  print('- %s' % command)
+  result = run(command, stdout=PIPE, stderr=PIPE, universal_newlines=True, shell=True)
+  if result.returncode != 0:
+    print("error while running '%s':\n" % command, '  ' + str(result.stderr).replace('\n', '\n  '))
+    exit(result.returncode)
+  return result.stdout
+
+
+print('')
+for example in examples:
+  print("running example %s" % example.name)
+  print("================" + ('=' * len(example.name)))
+  project = Path(".") / 'build' / example.name
+  configure = runCommand('cmake -H%s -B%s' % (example, project))
+  print('  ' + '\n  '.join([line for line in configure.split('\n') if 'CPM:' in line]))
+  build = runCommand('cmake --build %s -- -j%i' % (project, os.cpu_count() / 2))
+  print('  ' + '\n  '.join([line for line in build.split('\n') if 'Built target' in line]))
+  print('')

examples/catch2/CMakeLists.txt

@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleCatch2)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME fibonacci
+  GITHUB_REPOSITORY TheLartians/Fibonacci
+  VERSION 2.0
+)
+
+CPMAddPackage(
+  NAME Catch2
+  GITHUB_REPOSITORY catchorg/Catch2
+  VERSION 2.13.4
+)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleCatch2 main.cpp)
+target_link_libraries(CPMExampleCatch2 fibonacci Catch2)
+target_compile_features(CPMExampleCatch2 PRIVATE cxx_std_17)
+
+# ---- Enable testing ----
+
+enable_testing()
+add_test(CPMExampleCatch2 CPMExampleCatch2)

examples/catch2/main.cpp

@@ -0,0 +1,21 @@
+#define CATCH_CONFIG_MAIN
+
+#include <fibonacci.h>
+
+#include <catch2/catch.hpp>
+
+TEST_CASE("fibonacci") {
+  REQUIRE(fibonacci(0) == 0);
+  REQUIRE(fibonacci(1) == 1);
+  REQUIRE(fibonacci(2) == 1);
+  REQUIRE(fibonacci(3) == 2);
+  REQUIRE(fibonacci(4) == 3);
+  REQUIRE(fibonacci(5) == 5);
+  REQUIRE(fibonacci(13) == 233);
+}
+
+TEST_CASE("fastFibonacci") {
+  for (unsigned i = 0; i < 25; ++i) {
+    REQUIRE(fibonacci(i) == fastFibonacci(i));
+  }
+}

examples/cereal/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleCereal)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME cereal
+  VERSION 1.3.0
+  GITHUB_REPOSITORY USCiLab/cereal
+  OPTIONS "SKIP_PORTABILITY_TEST ON" "JUST_INSTALL_CEREAL ON"
+)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleCereal main.cpp)
+target_link_libraries(CPMExampleCereal cereal)
+target_compile_features(CPMExampleCereal PRIVATE cxx_std_17)

examples/cereal/main.cpp

@@ -0,0 +1,26 @@
+#define CATCH_CONFIG_MAIN
+
+#include <cereal/archives/json.hpp>
+#include <cereal/cereal.hpp>
+#include <sstream>
+#include <string>
+
+struct player_data {
+  int id{-1};
+  std::string name{};
+};
+
+template <typename Archive> void serialize(Archive &archive, player_data const &data) {
+  archive(cereal::make_nvp("id", data.id), cereal::make_nvp("name", data.name));
+}
+
+int main(int argc, char const *argv[]) {
+  player_data player{3, "Gamer One"};
+  std::ostringstream oss;
+  cereal::JSONOutputArchive output(oss);
+  output(cereal::make_nvp("player_data", player));
+
+  std::cout << oss.str() << std::endl;
+
+  return 0;
+}

examples/complex/CMakeLists.txt

@@ -1,55 +0,0 @@
-cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
-
-project(CPMTest)
-
-include(${CMAKE_CURRENT_SOURCE_DIR}/../../cmake/CPM.cmake)
-
-# ignore locally installed projects for reproducable builds
-set(CPM_REMOTE_PACKAGES_ONLY ON CACHE INTERNAL "")
-
-# util library
-CPMAddPackage(
-  NAME LHC
-  GIT_REPOSITORY https://github.com/TheLartians/LHC.git
-  VERSION 0.7
-)
-
-# will be ignored as newer version already added
-CPMAddPackage(
-  NAME LHC
-  GIT_REPOSITORY https://github.com/TheLartians/LHC.git
-  VERSION 0.2
-)
-
-# language bindings
-# uses git tag instead of version identifier
-# depends on visitor library that depends on Event library and LHC
-# CMake configuration arguments passed via OPTIONS
-CPMAddPackage(
-  NAME Glue
-  GIT_TAG 78af65625751ad15a42ca52b842863e85b5d2adc
-  GIT_REPOSITORY https://github.com/TheLartians/Glue.git
-  VERSION 0.5.1
-  OPTIONS 
-    "GLUE_ENABLE_LUA ON"
-    "GLUE_BUILD_LUA ON"
-)
-
-# parser library 
-# depends on LHC and Glue
-CPMAddPackage(
-  NAME LarsParser
-  GIT_REPOSITORY https://github.com/TheLartians/Parser.git
-  VERSION 1.8
-  OPTIONS 
-    "LARS_PARSER_BUILD_GLUE_EXTENSION ON"
-)
-
-# add executable
-set (CMAKE_CXX_STANDARD 17)
-add_executable(cpm-test-complex main.cpp)
-target_link_libraries(cpm-test-complex LHC LarsParser Glue)
-
-# tests
-enable_testing()
-add_test(cpm-test-complex cpm-test-complex)

examples/complex/main.cpp

@@ -1,52 +0,0 @@
-#include <lars/parser/extension.h>
-#include <lars/lua_glue.h>
-#include <stdexcept>
-
-int main() {
-  // create lua state
-  auto lua = lars::LuaState();
-  lua.open_libs();
-
-  // create extensions
-  lars::Extension extensions;
-
-  // add parser library to extension
-  extensions.add_extension("parser", lars::extensions::parser());
-
-  // connect parser extension to lua
-  extensions.connect(lua.get_glue());
-
-  // create a parser
-  lua.run(R"(
-    NumberMap = parser.Program.create()
-
-    NumberMap:setRule("Whitespace", "[ \t]")
-    NumberMap:setSeparatorRule("Whitespace")
-
-    NumberMap:setRuleWithCallback("Object", "'{' KeyValue (',' KeyValue)* '}'",function(e) 
-      local N = e:size()-1
-      local res = {}
-      for i=0,N do 
-        local a = e:get(i)
-        res[a:get(0):evaluate()] = a:get(1):evaluate() 
-      end
-      return res
-    end)
-
-    NumberMap:setRule("KeyValue", "Number ':' Number")
-
-    NumberMap:setRuleWithCallback("Number", "'-'? [0-9]+", function(e) return tonumber(e:string()); end)
-    
-    NumberMap:setStartRule("Object")
-  )");
-
-  // parse a string
-  lua.run("m = NumberMap:run('{1:3, 2:-1, 3:42}')");
-  
-  // check result
-  if (lua.get_numeric("m[1]") != 3) throw std::runtime_error("unexpected result");
-  if (lua.get_numeric("m[2]") != -1) throw std::runtime_error("unexpected result");
-  if (lua.get_numeric("m[3]") != 42) throw std::runtime_error("unexpected result");
-
-  return 0;
-}

examples/cxxopts/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleCXXOpts)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME cxxopts
+  GITHUB_REPOSITORY jarro2783/cxxopts
+  VERSION 2.2.0
+  OPTIONS "CXXOPTS_BUILD_EXAMPLES Off" "CXXOPTS_BUILD_TESTS Off"
+)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleCXXOpts main.cpp)
+target_link_libraries(CPMExampleCXXOpts cxxopts)
+target_compile_features(CPMExampleCXXOpts PRIVATE cxx_std_17)

examples/cxxopts/main.cpp

@@ -0,0 +1,21 @@
+#include <cxxopts.hpp>
+#include <iostream>
+
+int main(int argc, char** argv) {
+  cxxopts::Options options("MyProgram", "One line description of MyProgram");
+  options.add_options()("h,help", "Show help")("d,debug", "Enable debugging")(
+      "f,file", "File name", cxxopts::value<std::string>());
+
+  auto result = options.parse(argc, argv);
+
+  if (result["help"].as<bool>()) {
+    std::cout << options.help() << std::endl;
+    return 0;
+  }
+
+  for (auto arg : result.arguments()) {
+    std::cout << "option: " << arg.key() << ": " << arg.value() << std::endl;
+  }
+
+  return 0;
+}

examples/doctest/CMakeLists.txt

@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleDoctest)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME fibonacci
+  GITLAB_REPOSITORY TheLartians/Fibonacci
+  VERSION 2.0
+)
+
+CPMAddPackage(
+  NAME doctest
+  GITHUB_REPOSITORY onqtam/doctest
+  GIT_TAG 2.4.5
+)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleDoctest main.cpp)
+target_link_libraries(CPMExampleDoctest fibonacci doctest)
+target_compile_features(CPMExampleDoctest PRIVATE cxx_std_17)
+
+# ---- Enable testing ----
+
+enable_testing()
+add_test(CPMExampleDoctest CPMExampleDoctest)

examples/doctest/main.cpp

@@ -0,0 +1,20 @@
+#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
+
+#include <doctest/doctest.h>
+#include <fibonacci.h>
+
+TEST_CASE("fibonacci") {
+  CHECK(fibonacci(0) == 0);
+  CHECK(fibonacci(1) == 1);
+  CHECK(fibonacci(2) == 1);
+  CHECK(fibonacci(3) == 2);
+  CHECK(fibonacci(4) == 3);
+  CHECK(fibonacci(5) == 5);
+  CHECK(fibonacci(13) == 233);
+}
+
+TEST_CASE("fastfibonacci") {
+  for (unsigned i = 0; i < 25; ++i) {
+    CHECK(fibonacci(i) == fastFibonacci(i));
+  }
+}

examples/entt/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMEnTTExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME EnTT
+  VERSION 3.1.1
+  GITHUB_REPOSITORY skypjack/entt
+  # EnTT's CMakeLists screws with configuration options
+  DOWNLOAD_ONLY True
+)
+
+if(EnTT_ADDED)
+  add_library(EnTT INTERFACE)
+  target_include_directories(EnTT SYSTEM INTERFACE ${EnTT_SOURCE_DIR}/src)
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMEnTTExample main.cpp)
+target_compile_features(CPMEnTTExample PRIVATE cxx_std_17)
+target_link_libraries(CPMEnTTExample EnTT)

examples/entt/main.cpp

@@ -0,0 +1,56 @@
+#include <cstdint>
+#include <entt/entt.hpp>
+
+struct position {
+  float x;
+  float y;
+};
+
+struct velocity {
+  float dx;
+  float dy;
+};
+
+void update(entt::registry &registry) {
+  auto view = registry.view<position, velocity>();
+
+  for (auto entity : view) {
+    // gets only the components that are going to be used ...
+
+    auto &vel = view.get<velocity>(entity);
+
+    vel.dx = 0.;
+    vel.dy = 0.;
+
+    // ...
+  }
+}
+
+void update(std::uint64_t dt, entt::registry &registry) {
+  registry.view<position, velocity>().each([dt](auto &pos, auto &vel) {
+    // gets all the components of the view at once ...
+
+    pos.x += vel.dx * dt;
+    pos.y += vel.dy * dt;
+
+    // ...
+  });
+}
+
+int main() {
+  entt::registry registry;
+  std::uint64_t dt = 16;
+
+  for (auto i = 0; i < 10; ++i) {
+    auto entity = registry.create();
+    registry.assign<position>(entity, i * 1.f, i * 1.f);
+    if (i % 2 == 0) {
+      registry.assign<velocity>(entity, i * .1f, i * .1f);
+    }
+  }
+
+  update(dt, registry);
+  update(registry);
+
+  // ...
+}

examples/fmt/CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMJSONExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME fmt
+  GIT_TAG 7.1.3
+  GITHUB_REPOSITORY fmtlib/fmt
+)
+
+# ---- Executable ----
+
+add_executable(CPMFmtExample main.cpp)
+target_compile_features(CPMFmtExample PRIVATE cxx_std_17)
+target_link_libraries(CPMFmtExample fmt)

examples/fmt/main.cpp

@@ -0,0 +1,6 @@
+#include <fmt/format.h>
+
+int main() {
+  fmt::print("Hello, {}!\n", "world");
+  return 0;
+}

examples/gtest/CMakeLists.txt

@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleGtest)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME fibonacci
+  GITLAB_REPOSITORY TheLartians/Fibonacci
+  VERSION 2.0
+)
+
+CPMAddPackage(
+  NAME googletest
+  GITHUB_REPOSITORY google/googletest
+  GIT_TAG release-1.10.0
+  VERSION 1.10.0
+  OPTIONS "INSTALL_GTEST OFF" "gtest_force_shared_crt"
+)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleGtest main.cpp)
+target_link_libraries(CPMExampleGtest fibonacci gtest gtest_main gmock)
+target_compile_features(CPMExampleGtest PRIVATE cxx_std_17)
+
+# ---- Enable testing ----
+
+enable_testing()
+add_test(CPMExampleGtest CPMExampleGtest)

examples/gtest/main.cpp

@@ -0,0 +1,12 @@
+#include <fibonacci.h>
+#include <gtest/gtest.h>
+
+TEST(FibonacciTests, BasicChecks) {
+  ASSERT_TRUE(fibonacci(0) == 0);
+  ASSERT_TRUE(fibonacci(1) == 1);
+  ASSERT_TRUE(fibonacci(2) == 1);
+  ASSERT_TRUE(fibonacci(3) == 2);
+  ASSERT_TRUE(fibonacci(4) == 3);
+  ASSERT_TRUE(fibonacci(5) == 5);
+  ASSERT_TRUE(fibonacci(13) == 233);
+}

examples/json/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMJSONExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME nlohmann_json
+  VERSION 3.9.1
+  # not using the repo as it takes forever to clone
+  URL https://github.com/nlohmann/json/releases/download/v3.9.1/include.zip
+  URL_HASH SHA256=6bea5877b1541d353bd77bdfbdb2696333ae5ed8f9e8cc22df657192218cad91
+)
+
+if(nlohmann_json_ADDED)
+  add_library(nlohmann_json INTERFACE)
+  target_include_directories(nlohmann_json SYSTEM INTERFACE ${nlohmann_json_SOURCE_DIR}/include)
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMJSONExample main.cpp)
+target_compile_features(CPMJSONExample PRIVATE cxx_std_17)
+target_link_libraries(CPMJSONExample nlohmann_json)

examples/json/main.cpp

@@ -0,0 +1,17 @@
+#include <iomanip>
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main() {
+  nlohmann::json json = {{"pi", 3.141},
+                         {"happy", true},
+                         {"name", "Niels"},
+                         {"nothing", nullptr},
+                         {"answer", {{"everything", 42}}},
+                         {"list", {1, 0, 2}},
+                         {"object", {{"currency", "USD"}, {"value", 42.99}}}};
+
+  std::cout << "declared JSON object: " << std::setw(2) << json << std::endl;
+
+  return 0;
+}

examples/linenoise/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMlinenoiseExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME linenoise
+  GIT_TAG 1.0
+  GITHUB_REPOSITORY antirez/linenoise
+)
+
+if(linenoise_ADDED)
+  add_library(linenoise ${linenoise_SOURCE_DIR}/linenoise.c)
+  target_include_directories(linenoise SYSTEM PUBLIC ${linenoise_SOURCE_DIR})
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMlinenoiseExample main.cpp)
+target_compile_features(CPMlinenoiseExample PRIVATE cxx_std_17)
+target_link_libraries(CPMlinenoiseExample linenoise)

examples/linenoise/main.cpp

@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "linenoise.h"
+
+void completion(const char *buf, linenoiseCompletions *lc) {
+  if (buf[0] == 'h') {
+    linenoiseAddCompletion(lc, "hello");
+    linenoiseAddCompletion(lc, "hello there");
+  }
+}
+
+int main(int argc, char **argv) {
+  char *line;
+  char *prgname = argv[0];
+
+  /* Parse options, with --multiline we enable multi line editing. */
+  while (argc > 1) {
+    argc--;
+    argv++;
+    if (!strcmp(*argv, "--multiline")) {
+      linenoiseSetMultiLine(1);
+      printf("Multi-line mode enabled.\n");
+    } else if (!strcmp(*argv, "--keycodes")) {
+      linenoisePrintKeyCodes();
+      exit(0);
+    } else {
+      fprintf(stderr, "Usage: %s [--multiline] [--keycodes]\n", prgname);
+      exit(1);
+    }
+  }
+
+  /* Set the completion callback. This will be called every time the
+   * user uses the <tab> key. */
+  linenoiseSetCompletionCallback(completion);
+
+  /* Load history from file. The history file is just a plain text file
+   * where entries are separated by newlines. */
+  linenoiseHistoryLoad("history.txt"); /* Load the history at startup */
+
+  /* Now this is the main loop of the typical linenoise-based application.
+   * The call to linenoise() will block as long as the user types something
+   * and presses enter.
+   *
+   * The typed string is returned as a malloc() allocated string by
+   * linenoise, so the user needs to free() it. */
+  while ((line = linenoise("hello> ")) != NULL) {
+    /* Do something with the string. */
+    if (line[0] != '\0' && line[0] != '/') {
+      printf("echo: '%s'\n", line);
+      linenoiseHistoryAdd(line);           /* Add to the history. */
+      linenoiseHistorySave("history.txt"); /* Save the history on disk. */
+    } else if (!strncmp(line, "/historylen", 11)) {
+      /* The "/historylen" command will change the history len. */
+      int len = atoi(line + 11);
+      linenoiseHistorySetMaxLen(len);
+    } else if (line[0] == '/') {
+      printf("Unreconized command: %s\n", line);
+    }
+    free(line);
+  }
+  return 0;
+}

examples/range-v3/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMRangev3Example)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME range-v3
+  URL https://github.com/ericniebler/range-v3/archive/0.11.0.zip
+  VERSION 0.11.0
+  # the range-v3 CMakeLists screws with configuration options
+  DOWNLOAD_ONLY True
+)
+
+if(range-v3_ADDED)
+  add_library(range-v3 INTERFACE IMPORTED)
+  target_include_directories(range-v3 SYSTEM INTERFACE "${range-v3_SOURCE_DIR}/include")
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMRangev3Example main.cpp)
+target_compile_features(CPMRangev3Example PRIVATE cxx_std_17)
+target_link_libraries(CPMRangev3Example range-v3)

examples/range-v3/main.cpp

@@ -0,0 +1,41 @@
+// Range v3 library
+//
+//  Copyright Jeff Garland 2017
+//
+//  Use, modification and distribution is subject to the
+//  Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//
+// Project home: https://github.com/ericniebler/range-v3
+//
+
+//[any_all_none_of]]
+// Demonstrates any_of, all_of, none_of
+// output
+// vector: [6,2,3,4,5,6]
+// vector any_of is_six: true
+// vector all_of is_six: false
+// vector none_of is_six: false
+
+#include <iostream>
+#include <range/v3/algorithm/all_of.hpp>
+#include <range/v3/algorithm/any_of.hpp>
+#include <range/v3/algorithm/for_each.hpp>
+#include <range/v3/algorithm/none_of.hpp>
+#include <range/v3/view/all.hpp>
+#include <vector>
+using std::cout;
+
+auto is_six = [](int i) { return i == 6; };
+
+int main() {
+  std::vector<int> v{6, 2, 3, 4, 5, 6};
+  cout << std::boolalpha;
+  cout << "vector: " << ranges::view::all(v) << '\n';
+
+  cout << "vector any_of is_six: " << ranges::any_of(v, is_six) << '\n';
+  cout << "vector all_of is_six: " << ranges::all_of(v, is_six) << '\n';
+  cout << "vector none_of is_six: " << ranges::none_of(v, is_six) << '\n';
+}
+//[any_all_none_of]]

examples/simple/CMakeLists.txt

@@ -1,21 +0,0 @@
-cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
-
-project(CPMTest)
-
-# add dependencies
-include(${CMAKE_CURRENT_SOURCE_DIR}/../../cmake/CPM.cmake)
-
-CPMAddPackage(
-  NAME LarsParser
-  GIT_REPOSITORY https://github.com/TheLartians/Parser.git
-  VERSION 1.7
-)
-
-# add executable
-set (CMAKE_CXX_STANDARD 17)
-add_executable(cpm-test-simple main.cpp)
-target_link_libraries(cpm-test-simple LarsParser)
-
-# tests
-enable_testing()
-add_test(cpm-test-simple cpm-test-simple)

examples/simple/main.cpp

@@ -1,27 +0,0 @@
-#include <lars/parser/generator.h>
-
-int main() {
-  lars::ParserGenerator<float> g;
-
-  // Define grammar and evaluation rules
-  g.setSeparator(g["Whitespace"] << "[\t ]");
-  g["Sum"     ] << "Add | Subtract | Product";
-  g["Product" ] << "Multiply | Divide | Atomic";
-  g["Atomic"  ] << "Number | '(' Sum ')'";
-  g["Add"     ] << "Sum '+' Product"    >> [](auto e){ return e[0].evaluate() + e[1].evaluate(); };
-  g["Subtract"] << "Sum '-' Product"    >> [](auto e){ return e[0].evaluate() - e[1].evaluate(); };
-  g["Multiply"] << "Product '*' Atomic" >> [](auto e){ return e[0].evaluate() * e[1].evaluate(); };
-  g["Divide"  ] << "Product '/' Atomic" >> [](auto e){ return e[0].evaluate() / e[1].evaluate(); };
-  g["Number"  ] << "'-'? [0-9]+ ('.' [0-9]+)?" >> [](auto e){ return stof(e.string()); };
-  g.setStart(g["Sum"]);
-
-  // Execute a string
-  float result = g.run("1 + 2 * (3+4)/2 - 3");
-
-  // validate result
-  if (result == 5) {
-    return 0;
-  } else {
-    return 1;
-  }
-}

examples/simple_match/CMakeLists.txt

@@ -0,0 +1,25 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMSimpleMatchExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME simple_match
+  GIT_REPOSITORY https://github.com/jbandela/simple_match.git
+  GIT_TAG a3ab17f3d98db302de68ad85ed399a42ae41889e
+  DOWNLOAD_ONLY True
+)
+
+if(simple_match_ADDED)
+  add_library(simple_match INTERFACE IMPORTED)
+  target_include_directories(simple_match SYSTEM INTERFACE "${simple_match_SOURCE_DIR}/include")
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMSimpleMatchExample main.cpp)
+target_compile_features(CPMSimpleMatchExample PRIVATE cxx_std_17)
+target_link_libraries(CPMSimpleMatchExample simple_match)

examples/simple_match/main.cpp

@@ -0,0 +1,34 @@
+#include <iostream>
+#include <simple_match/simple_match.hpp>
+
+int main(int argc, char** argv) {
+  using namespace simple_match;
+  using namespace simple_match::placeholders;
+
+  std::string input;
+  std::cout << "please enter a number or 'quit' to exit" << std::endl;
+
+  while (true) {
+    std::cout << "> ";
+    std::getline(std::cin, input);
+    if (input == "quit") {
+      break;
+    }
+    int x;
+    try {
+      x = std::stoi(input);
+    } catch (std::invalid_argument&) {
+      std::cout << "invalid input" << std::endl;
+      continue;
+    }
+
+    match(
+        x, 1, []() { std::cout << "The answer is one\n"; }, 2,
+        []() { std::cout << "The answer is two\n"; }, _x < 10,
+        [](auto&& a) { std::cout << "The answer " << a << " is less than 10\n"; }, 10 < _x < 20,
+        [](auto&& a) { std::cout << "The answer " << a << " is between 10 and 20 exclusive\n"; }, _,
+        []() { std::cout << "Did not match\n"; });
+  }
+
+  return 0;
+}

examples/sol2/CMakeLists.txt

@@ -0,0 +1,43 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMSol2Example)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME lua
+  GIT_REPOSITORY https://github.com/lua/lua.git
+  VERSION 5.3.5
+  DOWNLOAD_ONLY YES
+)
+
+if(lua_ADDED)
+  # lua has no CMakeLists, so we create our own target
+
+  file(GLOB lua_sources ${lua_SOURCE_DIR}/*.c)
+  list(REMOVE_ITEM lua_sources "${lua_SOURCE_DIR}/lua.c" "${lua_SOURCE_DIR}/luac.c")
+  add_library(lua STATIC ${lua_sources})
+
+  target_include_directories(lua SYSTEM PUBLIC $<BUILD_INTERFACE:${lua_SOURCE_DIR}>)
+endif()
+
+CPMAddPackage(
+  NAME sol2
+  URL https://github.com/ThePhD/sol2/archive/v3.0.2.zip
+  VERSION 3.0.2
+  DOWNLOAD_ONLY YES
+)
+
+if(sol2_ADDED)
+  add_library(sol2 INTERFACE IMPORTED)
+  target_include_directories(sol2 SYSTEM INTERFACE ${sol2_SOURCE_DIR}/include)
+  target_link_libraries(sol2 INTERFACE lua)
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMSol2Example main.cpp)
+target_compile_features(CPMSol2Example PRIVATE cxx_std_17)
+target_link_libraries(CPMSol2Example sol2)

examples/sol2/main.cpp

@@ -0,0 +1,17 @@
+#include <cassert>
+#include <sol/sol.hpp>
+
+struct vars {
+  int boop = 0;
+};
+
+int main() {
+  sol::state lua;
+  lua.open_libraries(sol::lib::base);
+  lua.new_usertype<vars>("vars", "boop", &vars::boop);
+  lua.script(
+      "beep = vars.new()\n"
+      "beep.boop = 1\n"
+      "print('beep boop')");
+  assert(lua.get<vars>("beep").boop == 1);
+}

examples/spdlog/CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMSpdlogExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME spdlog
+  GITHUB_REPOSITORY gabime/spdlog
+  VERSION 1.8.2
+)
+
+# ---- Executable ----
+
+add_executable(CPMSpdlogExample main.cpp)
+target_compile_features(CPMSpdlogExample PRIVATE cxx_std_17)
+target_link_libraries(CPMSpdlogExample spdlog)

examples/spdlog/main.cpp

@@ -0,0 +1,6 @@
+#include <spdlog/spdlog.h>
+
+int main() {
+  spdlog::info("Hello, world!");
+  return 0;
+}

examples/yaml/CMakeLists.txt

@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMYamlExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME yaml-cpp
+  GIT_REPOSITORY https://github.com/jbeder/yaml-cpp.git
+  VERSION 0.6.3
+  GIT_TAG yaml-cpp-0.6.3
+  OPTIONS "YAML_CPP_BUILD_TESTS Off" "YAML_CPP_BUILD_CONTRIB Off" "YAML_CPP_BUILD_TOOLS Off"
+)
+
+# ---- Executable ----
+
+add_executable(CPMYamlExample main.cpp)
+target_compile_features(CPMYamlExample PRIVATE cxx_std_17)
+target_link_libraries(CPMYamlExample yaml-cpp)

examples/yaml/main.cpp

@@ -0,0 +1,15 @@
+#include <yaml-cpp/yaml.h>
+
+#include <iostream>
+
+int main(int argc, char** argv) {
+  if (argc != 2) {
+    std::cout << "usage: " << argv[0] << " <path to yaml file>" << std::endl;
+    return 1;
+  }
+
+  YAML::Node config = YAML::LoadFile(argv[1]);
+  std::cout << "Parsed YAML:\n" << config << std::endl;
+
+  return 0;
+}

examples/yaml/monsters.yaml

@@ -0,0 +1,21 @@
+- name: Ogre
+  position: [0, 5, 0]
+  powers:
+    - name: Club
+      damage: 10
+    - name: Fist
+      damage: 8
+- name: Dragon
+  position: [1, 0, 10]
+  powers:
+    - name: Fire Breath
+      damage: 25
+    - name: Claws
+      damage: 15
+- name: Wizard
+  position: [5, -3, 0]
+  powers:
+    - name: Acid Rain
+      damage: 50
+    - name: Staff
+      damage: 3

test/CMakeLists.txt

@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMTests)
+
+file(GLOB tests "${CMAKE_CURRENT_SOURCE_DIR}/unit/*.cmake")
+
+enable_testing()
+
+foreach(test ${tests})
+  message(STATUS "adding test: ${test}")
+  add_test(NAME ${test} COMMAND ${CMAKE_COMMAND} -DCPM_PATH=${CMAKE_CURRENT_SOURCE_DIR}/../cmake -P
+                                "${test}"
+  )
+endforeach()
+
+add_custom_target(test-verbose COMMAND ${CMAKE_CTEST_COMMAND} -C Debug --verbose)

test/style/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMStyleCheck)
+
+include(${CMAKE_CURRENT_LIST_DIR}/../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME Format.cmake
+  VERSION 1.6
+  GITHUB_REPOSITORY TheLartians/Format.cmake
+  OPTIONS "FORMAT_CHECK_CMAKE ON"
+)

test/unit/cache.cmake

@@ -0,0 +1,137 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/testing.cmake)
+include(CMakePackageConfigHelpers)
+
+set(CPM_SOURCE_CACHE_DIR "${CMAKE_CURRENT_BINARY_DIR}/CPM")
+set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/remote_dependency)
+
+function(clear_cache)
+  message(STATUS "clearing CPM cache")
+  file(REMOVE_RECURSE ${CPM_SOURCE_CACHE_DIR})
+  assert_not_exists("${CPM_SOURCE_CACHE_DIR}")
+endfunction()
+
+function(update_cmake_lists)
+  configure_package_config_file(
+    "${CMAKE_CURRENT_LIST_DIR}/remote_dependency/CMakeLists.txt.in"
+    "${CMAKE_CURRENT_LIST_DIR}/remote_dependency/CMakeLists.txt"
+    INSTALL_DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/junk
+  )
+endfunction()
+
+function(reset_test)
+  clear_cache()
+  file(REMOVE_RECURSE ${TEST_BUILD_DIR})
+  update_cmake_lists()
+endfunction()
+
+set(FIBONACCI_VERSION 1.0)
+
+# Read CPM_SOURCE_CACHE from arguments
+
+reset_test()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}"
+          "-DCPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
+
+file(GLOB FIBONACCI_VERSIONs "${CPM_SOURCE_CACHE_DIR}/fibonacci/*")
+list(LENGTH FIBONACCI_VERSIONs FIBONACCI_VERSION_count)
+assert_equal(${FIBONACCI_VERSION_count} "1")
+
+file(GLOB fibonacci_versions "${CPM_SOURCE_CACHE_DIR}/fibonacci/*")
+list(LENGTH fibonacci_versions fibonacci_version_count)
+assert_equal(${fibonacci_version_count} "1")
+
+# Update dependency and keep CPM_SOURCE_CACHE
+
+set(FIBONACCI_VERSION 2.0)
+update_cmake_lists()
+
+execute_process(COMMAND ${CMAKE_COMMAND} ${TEST_BUILD_DIR} RESULT_VARIABLE ret)
+
+assert_equal(${ret} "0")
+
+file(GLOB FIBONACCI_VERSIONs "${CPM_SOURCE_CACHE_DIR}/fibonacci/*")
+list(LENGTH FIBONACCI_VERSIONs FIBONACCI_VERSION_count)
+assert_equal(${FIBONACCI_VERSION_count} "2")
+
+# Clear cache and update
+
+clear_cache()
+
+execute_process(COMMAND ${CMAKE_COMMAND} ${TEST_BUILD_DIR} RESULT_VARIABLE ret)
+
+assert_equal(${ret} "0")
+assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
+
+# Read CPM_SOURCE_CACHE from environment
+
+reset_test()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
+          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
+
+# Reuse cached packages for other build
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
+          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}-2"
+  RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+
+# Overwrite CPM_SOURCE_CACHE with argument
+
+reset_test()
+
+execute_process(
+  COMMAND
+    ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CMAKE_CURRENT_BINARY_DIR}/junk" ${CMAKE_COMMAND}
+    "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}"
+    "-DCPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}"
+  RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
+
+# Use NO_CACHE option
+
+set(FIBONACCI_PACKAGE_ARGS "NO_CACHE YES")
+set(FIBONACCI_VERSION 1.0)
+update_cmake_lists()
+reset_test()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
+          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+assert_not_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
+
+# Use commit hash after version
+
+set(FIBONACCI_PACKAGE_ARGS "NO_CACHE YES GIT_TAG e9ebf168ca0fffaa4ef8c6fefc6346aaa22f6ed5")
+set(FIBONACCI_VERSION 1.1)
+update_cmake_lists()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
+          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+assert_not_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")

test/unit/dependency_properties.cmake

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+set(CPM_DRY_RUN ON)
+
+CPMAddPackage(NAME A GIT_TAG 1.2.3)
+
+CPMAddPackage(NAME A VERSION 1.2.3)
+
+CPMGetPackageVersion(A VERSION)
+assert_equal(${VERSION} "1.2.3")
+
+CPMAddPackage(NAME B VERSION 2.4.1)
+
+CPMAddPackage(NAME B GIT_TAG v2.3.1)
+
+CPMGetPackageVersion(B VERSION)
+assert_equal(${VERSION} "2.4.1")
+
+CPMAddPackage(
+  NAME C
+  GIT_TAG v3.1.2-a
+  VERSION 3.1.2
+)
+
+CPMGetPackageVersion(C VERSION)
+assert_equal(${VERSION} "3.1.2")

test/unit/is_git_tag_commit_hash.cmake

@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+cpm_is_git_tag_commit_hash("v1.2.3" RESULT)
+assert_equal("0" ${RESULT})
+
+cpm_is_git_tag_commit_hash("asio-1-12-1" RESULT)
+assert_equal("0" ${RESULT})
+
+cpm_is_git_tag_commit_hash("513039e3cba83284cec71287fd829865b9f423bc" RESULT)
+assert_equal("1" ${RESULT})
+
+cpm_is_git_tag_commit_hash("513039E3CBA83284CEC71287FD829865B9F423BC" RESULT)
+assert_equal("1" ${RESULT})
+
+cpm_is_git_tag_commit_hash("513039E" RESULT)
+assert_equal("1" ${RESULT})
+
+cpm_is_git_tag_commit_hash("513039E3CBA8" RESULT)
+assert_equal("1" ${RESULT})

test/unit/local_dependency/.gitignore

@@ -0,0 +1,2 @@
+/CMakeLists.txt
+/package-lock.cmake

test/unit/local_dependency/ModuleCMakeLists.txt.in

@@ -0,0 +1,34 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMTest)
+
+# ---- Options ----
+
+option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
+
+# ---- Dependencies ----
+
+include(@CPM_PATH@/CPM.cmake)
+
+CPMAddPackage(
+  NAME @TEST_DEPENDENCY_NAME@
+  SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/dependency
+)
+
+# ---- check if generated modules override find_package ----
+
+if (@test_check_find_package@)
+  find_package(@TEST_DEPENDENCY_NAME@ REQUIRED)
+endif()
+
+# ---- Call dependency method to validate correct addition of directory ----
+
+dependency_function()
+
+# ---- Check parameters ----
+
+include(@CPM_PATH@/testing.cmake)
+
+ASSERT_TRUTHY(@TEST_DEPENDENCY_NAME@_ADDED)
+ASSERT_DEFINED(@TEST_DEPENDENCY_NAME@_SOURCE_DIR)
+ASSERT_DEFINED(@TEST_DEPENDENCY_NAME@_BINARY_DIR)

test/unit/local_dependency/OverrideCMakeLists.txt.in

@@ -0,0 +1,27 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMTest)
+
+# ---- Options ----
+
+option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
+
+# ---- Dependencies ----
+
+include(@CPM_PATH@/CPM.cmake)
+
+CPMAddPackage(
+  NAME Dependency
+)
+
+# ---- Call dependency method to validate correct addition of directory ----
+
+dependency_function()
+
+# ---- Check parameters ----
+
+include(@CPM_PATH@/testing.cmake)
+
+ASSERT_TRUTHY(Dependency_ADDED)
+ASSERT_DEFINED(Dependency_SOURCE_DIR)
+ASSERT_DEFINED(Dependency_BINARY_DIR)

test/unit/local_dependency/PackageLockCMakeLists.txt.in

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMTest)
+
+# ---- Options ----
+
+option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
+
+# ---- Dependencies ----
+
+include(@CPM_PATH@/CPM.cmake)
+CPMUsePackageLock(package-lock.cmake)
+
+@PREPARE_CODE@
+
+CPMGetPackage(Dependency)
+
+# ---- Call dependency method to validate correct addition of directory ----
+
+dependency_function()

test/unit/local_dependency/dependency/CMakeLists.txt

@@ -0,0 +1,3 @@
+function(dependency_function)
+  message("called external method")
+endfunction()

test/unit/modules.cmake

@@ -0,0 +1,28 @@
+include(CMakePackageConfigHelpers)
+include(${CPM_PATH}/testing.cmake)
+
+set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/modules)
+
+function(init_project_with_dependency TEST_DEPENDENCY_NAME)
+  configure_package_config_file(
+    "${CMAKE_CURRENT_LIST_DIR}/local_dependency/ModuleCMakeLists.txt.in"
+    "${CMAKE_CURRENT_LIST_DIR}/local_dependency/CMakeLists.txt"
+    INSTALL_DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/junk
+  )
+
+  execute_process(
+    COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
+    RESULT_VARIABLE ret
+  )
+
+  assert_equal(${ret} "0")
+endfunction()
+
+init_project_with_dependency(A)
+assert_exists(${TEST_BUILD_DIR}/CPM_modules)
+assert_exists(${TEST_BUILD_DIR}/CPM_modules/FindA.cmake)
+assert_not_exists(${TEST_BUILD_DIR}/CPM_modules/FindB.cmake)
+
+init_project_with_dependency(B)
+assert_not_exists(${TEST_BUILD_DIR}/CPM_modules/FindA.cmake)
+assert_exists(${TEST_BUILD_DIR}/CPM_modules/FindB.cmake)

test/unit/package-lock.cmake

@@ -0,0 +1,53 @@
+include(CMakePackageConfigHelpers)
+include(${CPM_PATH}/testing.cmake)
+
+set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/package-lock)
+
+function(configure_with_declare DECLARE_DEPENDENCY)
+  execute_process(COMMAND ${CMAKE_COMMAND} -E rm -rf ${TEST_BUILD_DIR})
+
+  if(DECLARE_DEPENDENCY)
+    set(PREPARE_CODE
+        "CPMDeclarePackage(Dependency
+      NAME Dependency
+      SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/local_dependency/dependency
+    )"
+    )
+  else()
+    set(PREPARE_CODE "")
+  endif()
+
+  configure_package_config_file(
+    "${CMAKE_CURRENT_LIST_DIR}/local_dependency/PackageLockCMakeLists.txt.in"
+    "${CMAKE_CURRENT_LIST_DIR}/local_dependency/CMakeLists.txt"
+    INSTALL_DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/junk
+  )
+
+  execute_process(
+    COMMAND ${CMAKE_COMMAND} -H${CMAKE_CURRENT_LIST_DIR}/local_dependency -B${TEST_BUILD_DIR}
+            -DCPM_INCLUDE_ALL_IN_PACKAGE_LOCK=1 RESULT_VARIABLE ret
+  )
+
+  assert_equal(${ret} "0")
+endfunction()
+
+function(update_package_lock)
+  execute_process(
+    COMMAND ${CMAKE_COMMAND} --build ${TEST_BUILD_DIR} --target cpm-update-package-lock
+    RESULT_VARIABLE ret
+  )
+
+  assert_equal(${ret} "0")
+endfunction()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E rm -f ${CMAKE_CURRENT_LIST_DIR}/local_dependency/package-lock.cmake
+)
+configure_with_declare(YES)
+assert_not_exists(${CMAKE_CURRENT_LIST_DIR}/local_dependency/package-lock.cmake)
+update_package_lock()
+assert_exists(${CMAKE_CURRENT_LIST_DIR}/local_dependency/package-lock.cmake)
+configure_with_declare(NO)
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E rm -f ${CMAKE_CURRENT_LIST_DIR}/local_dependency/package-lock.cmake
+)

test/unit/package-lock_prettify.cmake

@@ -0,0 +1,42 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+# cmake-format: off
+cpm_prettify_package_arguments(PRETTY_ARGN false
+  NAME Dependency
+  SOURCE_DIR ${CMAKE_SOURCE_DIR}/local_dependency/dependency
+  UPDATE_DISCONNECTED ON
+  TESTCUSTOMDATA TRUE
+)
+# cmake-format: on
+set(EXPECTED_UNCOMMENTED
+    "  NAME Dependency
+  SOURCE_DIR \${CMAKE_SOURCE_DIR}/local_dependency/dependency
+  UPDATE_DISCONNECTED ON TESTCUSTOMDATA TRUE
+"
+)
+assert_equal(${PRETTY_ARGN} ${EXPECTED_UNCOMMENTED})
+
+# cmake-format: off
+cpm_prettify_package_arguments(PRETTY_ARGN true
+  NAME Dependency
+  SOURCE_DIR ${CMAKE_SOURCE_DIR}/local_dependency/dependency
+  UPDATE_DISCONNECTED ON
+  TESTCUSTOMDATA TRUE
+)
+# cmake-format: on
+set(EXPECTED_COMMENTED
+    "#  NAME Dependency
+#  SOURCE_DIR \${CMAKE_SOURCE_DIR}/local_dependency/dependency
+#  UPDATE_DISCONNECTED ON TESTCUSTOMDATA TRUE
+"
+)
+assert_equal(${PRETTY_ARGN} ${EXPECTED_COMMENTED})
+
+cpm_prettify_package_arguments(PRETTY_ARGN true "local directory")
+set(EXPECTED_COMMENTED_LOCALDIR "#  local directory
+"
+)
+assert_equal(${PRETTY_ARGN} ${EXPECTED_COMMENTED_LOCALDIR})

test/unit/package-override.cmake

@@ -0,0 +1,20 @@
+include(CMakePackageConfigHelpers)
+include(${CPM_PATH}/testing.cmake)
+
+set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/project-override)
+
+execute_process(COMMAND ${CMAKE_COMMAND} -E rm -rf ${TEST_BUILD_DIR})
+
+configure_package_config_file(
+  "${CMAKE_CURRENT_LIST_DIR}/local_dependency/OverrideCMakeLists.txt.in"
+  "${CMAKE_CURRENT_LIST_DIR}/local_dependency/CMakeLists.txt"
+  INSTALL_DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/junk
+)
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -H${CMAKE_CURRENT_LIST_DIR}/local_dependency -B${TEST_BUILD_DIR}
+          -DCPM_Dependency_SOURCE=${CMAKE_CURRENT_LIST_DIR}/local_dependency/dependency
+  RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")

test/unit/remote_dependency/.gitignore

@@ -0,0 +1 @@
+/CMakeLists.txt

test/unit/remote_dependency/CMakeLists.txt.in

@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleCatch2)
+
+# ---- Options ----
+
+option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
+
+# ---- Dependencies ----
+
+include(@CPM_PATH@/CPM.cmake)
+
+CPMAddPackage(
+  NAME fibonacci
+  GIT_REPOSITORY https://github.com/TheLartians/Fibonacci.git
+  VERSION @FIBONACCI_VERSION@
+  @FIBONACCI_PACKAGE_ARGS@
+)
+
+# ---- Create binary ----
+
+add_executable(CPMExampleCatch2 main.cpp)
+target_link_libraries(CPMExampleCatch2 fibonacci)
+set_target_properties(CPMExampleCatch2 PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-Wall -pedantic -Wextra -Werror")
+
+# ---- Check parameters ----
+
+include(@CPM_PATH@/testing.cmake)
+
+ASSERT_TRUTHY(fibonacci_ADDED)
+ASSERT_DEFINED(fibonacci_SOURCE_DIR)
+ASSERT_DEFINED(fibonacci_BINARY_DIR)

test/unit/remote_dependency/main.cpp

@@ -0,0 +1,10 @@
+#define CATCH_CONFIG_MAIN
+
+#include <fibonacci.h>
+
+#include <iostream>
+
+int main() {
+  std::cout << "fib(10) = " << fastFibonacci(10) << std::endl;
+  return 0;
+}

test/unit/source_dir.cmake

@@ -0,0 +1,19 @@
+include(CMakePackageConfigHelpers)
+include(${CPM_PATH}/testing.cmake)
+
+set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/source_dir)
+
+set(TEST_DEPENDENCY_NAME Dependency)
+
+configure_package_config_file(
+  "${CMAKE_CURRENT_LIST_DIR}/local_dependency/ModuleCMakeLists.txt.in"
+  "${CMAKE_CURRENT_LIST_DIR}/local_dependency/CMakeLists.txt"
+  INSTALL_DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/junk
+)
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
+  RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")

test/unit/version_from_git_tag.cmake

@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+cpm_get_version_from_git_tag("1.2.3" VERSION)
+assert_equal("1.2.3" ${VERSION})
+
+cpm_get_version_from_git_tag("v1.2.3" VERSION)
+assert_equal("1.2.3" ${VERSION})
+
+cpm_get_version_from_git_tag("1.2.3-a" VERSION)
+assert_equal("1.2.3" ${VERSION})
+
+cpm_get_version_from_git_tag("v1.2.3-a" VERSION)
+assert_equal("1.2.3" ${VERSION})