Co[ro]nan is an example C++20 CLI and Qt project using conan and CMake. It reads the latest data of Corona (Covid-19) cases for a country from the COVID-19 Statistics API.

The COVID-19 Statistics API provides statistics via REST API from the Johns Hopkins CSSE.

This projects is a C++ project template. It includes everything a "Modern" C++ project possibly needs:

• C++ 20 Standard

  • GCC (>= gcc-12)
  • Clang (>= clang-13)
  • Visual Studio 2022

• conan package Manager

• Dependencies:

  • to install:
    • Qt6 (minimal version required: 6.4)
  • with conan:
    • Poco Networking library
    • RapidJSON
    • Lyra command line arguments parser
    • {fmt} formatting library (std::print is C++23 and therefore not used yet)
    • date date and time library (std::chrono::year_month_day is not fully supported in older c++20 compilers (gcc 12, 13 and clang 13-16) therefor it is not used yet)
    • Catch2 (for unittests)_

• Unittests with Coverage using Catch2

• CMake with CMakePresets (CMake >= 3.23)

• CPack packaging:

  • tar gzip archive
  • Debian package
  • Qt Installer Framework
  • WIX

• Build Caching support:

  • ccache
  • sccache

• Static Analyzer support:

  • clang-tidy
  • cppcheck
  • include-what-you-use
  • link-what-you-use

• Sanitizers support:

  • Address Sanitizer
  • Leak Sanitizer
  • Undefined Behavior Sanitizer
  • Thread Sanitizer
  • Memory Sanitizer

• Documentation Generation using

  • Doxygen using the "doxygen-awesome-sidebar-only" theme by
  • doxygen-awesome-css by default

• Code formatting:

  • clang-format for C++ files
  • cmake-format for CMake files

• Pre-commit-hooks support

• Nix environment support

• gitpod support

• Continuous integration (CI):

  • GitHub Action

    • Mac OS X

      • 13 (AppleClang 14)
      • 14 (AppleClang 15)
      • 15 (AppleClang 15)

    • Ubuntu 22.04

      • GCC 12
      • Clang 13, 14 & 15

    • Ubuntu 24.04

      • GCC 13 & 14
      • Clang 16, 17 & 18

    • Windows

      • Visual Studio 2022

    • Nix

      • GCC 14
      • Clang 18

    • Codacy Security Scan

    • CodeQL Static Analysis

    • Coverity Scan Static Analysis

    • Codecov Coverage Reporter

    • Sonar Cloud Static Analysis

  • AppVeyor

    • Windows Visual Studio 2019

To build the project you need python and a recent conan version, a recent version of CMake (>= 3.23), a modern C++ compiler (C++20 support) and Qt6 with QtCharts.

To install all python requirements for documentation generation, build and coverage generation (including conan and cmake) use:

pip3 install -r py-requirements.txt

You have the following options to build the project

Use build script:

In a linux shell you can build the project with the provided build.sh script. E.g. to build in folder build execute:

./build.sh ./build

See ./build.sh -h for more options

CMake:

You can also build it yourself using CMake and conan

• Install dependencies with conan

  conan install . --build=missing --settings=build_type=Debug

  Because the conan cmake_layout and the CMakeDeps generator is used, the necessary cmake files used with find_packages() are generated into build\<build_type>\generators. CMAKE_PREFIX_PATH is adapted accordingly in the root CMakeLists.txt.

• Without CMake Presets

  cmake -S . -B ./build -DCMAKE_BUILD_TYPE=Debug
  cmake --build ./build

• With CMake Presets

  cmake -S . --preset=linux-gcc-debug
  cmake --build --preset=gcc-debug

  or any other CMakePresets.

For source code formatting clang-format for C++ files and cmake-format for the CMake files are used. Run format_source_files.sh to format all C++ and CMake files.

Note: Delete the build directory before formatting, otherwise all CMake files in the build folder will be formatted as well, what may take a while.

• DOWNLOAD_QT6: Download and build Qt6 otherwise use installed. Default: OFF
• ENABLE_TESTING: Build (and run) unittests. Default: ON
• ENABLE_BUILD_WITH_TIME_TRACE: Enable Clang Time Trace Feature. Default: OFF
• ENABLE_PCH: Enable Precompiled Headers. Default: OFF
• ENABLE_CACHE: Enable caching if available, e.g. ccache or sccache. Default: ON
• ENABLE_COVERAGE: Enable coverage reporting for gcc/clang. Default: OFF
• ENABLE_DOXYGEN: Enable doxygen documentation build (Doxygen must be installed). Default: ON if Doxygen is installed OFF otherwise.
• ENABLE_SANITIZERS: Enable supported sanitizers. Default: OFF
  • ENABLE_SANITIZER_ADDRESS: Enable address sanitizer. Default: ON if supported by the compiler and ENABLE_SANITIZERS is ON otherwise OFF.
  • ENABLE_SANITIZER_LEAK: Enable leak sanitizer. Default: OFF
  • ENABLE_SANITIZER_UNDEFINED_BEHAVIOR: Enable undefined behavior sanitizer. Default: ON if supported by the compiler and ENABLE_SANITIZERS is ON otherwise OFF.
  • ENABLE_SANITIZER_THREAD: Enable thread sanitizer. Default: OFF
  • ENABLE_SANITIZER_MEMORY: Enable memory sanitizer. Default: OFF
• ENABLE_IPO: Enable intermodular optimization, aka Link Time Optimization (LTO). Default: OFF
• ENABLE_CPPCHECK: Enable static analysis with cppcheck. Default: ON if cppcheck is installed OFF otherwise.
• ENABLE_CLANG_TIDY: Enable static analysis with clang-tidy. Default: ON if clang-tidy is installed OFF otherwise.
• ENABLE_INCLUDE_WHAT_YOU_USE: Enable static analysis with include-what-you-use. Default: ON if include-what-you-use is installed OFF otherwise.
• ENABLE_LINK_WHAT_YOU_USE : Enable link what you use cmake built-in static analysis. _Default: OFF
• WARNINGS_AS_ERRORS: Treat compiler warnings as errors. _Default: OFF

The following Pre-commit-hooks are used to check and format files before committing:

• check-added-large-files: Prevent giant files (> 500kB) from being committed.
• fix-byte-order-marker: Forbid files which have a UTF-8 byte-order marker
• check-case-conflict: Check for files with names that would conflict on a case-insensitive filesystem like MacOS HFS+ or Windows FAT.
• check-merge-conflict: Check for files that contain merge conflict strings.
• check-symlinks: Checks for symlinks which do not point to anything.
• check-yaml: Attempts to load all yaml files to verify syntax.
• check-json: Attempts to load all json files to verify syntax.
• check-toml: Attempts to load all TOML files to verify syntax.
• check-executables-have-shebangs: Checks that non-binary executables have a proper shebang.
• end-of-file-fixer: Makes sure files end in a newline and only a newline.
• mixed-line-ending: Replaces or checks mixed line ending.
• trailing-whitespace: Trims trailing whitespace in markdown
• clang-format: Format C++ files using clang-format
• cmake-format: Format CMake files using cmake-format
• yamllint: Linter for yaml files
• yamlfmt: Format yaml files

Please install pre-commit hooks before committing any code.

pre-commit install -f --hook-type pre-commit

To manually check all files run:

pre-commit run --all-files

To start right away without installing anything on your local machine, you can simply use the button in the Project State section at the top of this README.

If you have direnv and nix installed everything should be setup to start upon entering the project folder, if use nix is not commented out in .envrc. gcc (gcc14) is set as default C and C++ compiler. If you prefer clang (clang_18) change it in .envrc

You can also use nix-shell directly to build when use nix is disabled, e.g.:

nix-shell --command "conan profile detect"
nix-shell --command "conan install . --build=missing --settings=build_type=Debug"
nix-shell --command "cmake -S . --preset=linux-debug-ninja
nix-shell --command "cmake --build --preset=ninja-debug

When using nix, a new cmake is available and therefore configure and build CMakePresets can be used.