ModernCppStarter/README.md

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# ModernCppStarter

Setting up a new C++ project usually requires a significant amount of preparation and boilerplate code, even more so for modern C++ projects with tests, executables and contiguous integration.
This template is the result of learnings from many previous projects and should help reduce the work required to setup up a modern C++ project.

## Features

- Modern CMake practices
- Suited for single header libraries and projects of any scale
- Separation into library and executable code
- Integrated test suite
- Continuous integration via [GitHub Actions](https://help.github.com/en/actions/)
- Code coverage via [codecov](https://codecov.io)
- Code formatting enforced by [clang-format](https://clang.llvm.org/docs/ClangFormat.html) via [Format.cmake](https://github.com/TheLartians/Format.cmake)
- Reproducible dependency management via [CPM.cmake](https://github.com/TheLartians/CPM.cmake)
- Installable target with versioning information via [PackageProject.cmake](https://github.com/TheLartians/PackageProject.cmake)

## Usage

### Adjust the template to your needs

- Use this repo [as a template](https://help.github.com/en/github/creating-cloning-and-archiving-repositories/creating-a-repository-from-a-template) and replace all occurrences of "Greeter" in the relevant CMakeLists.txt with the name of your project
- Replace the source files with your own
- For single-header libraries: see the comments in [CMakeLists.txt](CMakeLists.txt)
- Add your project's codecov token to your project's github secrets under `CODECOV_TOKEN`
- Happy coding!

Eventually, you can remove any unused files, such as the standalone directory or irrelevant github workflows for your project.

### Build and run the standalone target

Use the following command to build and run the executable target.

```bash
cmake -Hstandalone -Bbuild/standalone
cmake --build build/standalone
./build/standalone/Greeter --help
```

### Build and run test suite

Use the following commands from the project's root directory to run the test suite.

```bash
cmake -Htest -Bbuild/test
cmake --build build/test
CTEST_OUTPUT_ON_FAILURE=1 cmake --build build/test --target test

# or simply call the executable: 
./build/test/GreeterTests
```

To collect code coverage information, run CMake with the `-DENABLE_TEST_COVERAGE=1` option.

### Run clang-format

Use the following commands from the project's root directory to run clang-format (must be installed on the host system).

```bash
cmake -Htest -Bbuild/test

# view changes
cmake --build build/test --target format

# apply changes
cmake --build build/test --target fix-format
```

See [Format.cmake](https://github.com/TheLartians/Format.cmake) for more options.

## FAQ

  - Can I use this for header-only libraries?

    Yes, however you will need to change the library type to an `INTERFACE` library as documented in the [CMakeLists.txt](CMakeLists.txt).

  - I see you are using `GLOB` to add source files in CMakeLists.txt. Isn't that evil?

    Glob is considered bad because any changes to the source file structure [might not be automatically caught](https://cmake.org/cmake/help/latest/command/file.html#filesystem) by CMake's builders and you will need to manually invoke CMake on changes.
    I personally prefer the `GLOB` solution for its simplicity, but feel free to change it to explicitly listing sources.

  - You recommend to add external dependencies using CPM.cmake. Will this force users of my library to use CPM as well?

    [CPM.cmake](https://github.com/TheLartians/CPM.cmake) should be invisible to library users as it's a self-contained CMake Script.
    If problems do arise, users can always opt-out by defining `CPM_USE_LOCAL_PACKAGES`, which will override all calls to `CPMAddPackage` with `find_package`.
    Alternatively, you could use `CPMFindPackage` instead of `CPMAddPackage`, which will try to use `find_package` before calling `CPMAddPackage` as a fallback.
    Both approaches should be compatible with common C++ package managers without modifications, however come with the cost of reproducible builds.

  - Can I configure and build my project offline?

    Using CPM, all missing dependencies are downloaded at configure time.
    To avoid redundant downloads, it's recommended to set a CPM cache directory, e.g.: `export CPM_SOURCE_CACHE=$HOME/.cache/CPM`.
    This will also allow offline configurations if all dependencies are present.
    No internet connection is required for building.

  - Can I use CPack to create a package installer for my project?

    As there are a lot of possible options and configurations, this is not (yet) in the scope of this template. See the [CPack documentation](https://cmake.org/cmake/help/latest/module/CPack.html) for more information on setting up CPack installers.

## Coming soon

- Script to automatically adjust the template for new projects