YACS - Yet Another C++ Starter

Uses Catch2 for testing. Choose between conan/CMake or GNU make for builds.

Motivation

There are many high-quality C++ boilerplates in existence already. However, I have a couple reasons for wanting to build my own. First, I don't want to learn CMake (yet). And also, I think I'll be happier if things are set up just the way I like.

Goals

• Easy. "Just Works", even when adding dependencies.
• Simple, understandable code.
• Testing is built-in.
• Educational: well-commented and able to teach someone new to build systems

Boilerplate Types, Quickstart

This repository contains two folders, full-build-system and minimal. Each contains one style of boilerplate, which will be explained below.

If you're anxious to get started, copy either one of those directories to somewhere on your computer and start coding. Note that full-build-system requires conan (pip3 install --user conan). For more information on each, read on.

Minimal

The goal of this boilerplate is to provide the simplest possible build solution while still providing basic features. It is intended to be used for PoCs, experiments, or projects that have few dependencies.

Features:

• Only re-compiles changed files
• If a header file is changed, the associated source file is recompiled
• Fairly modular and DRY
• Some sensible default command line options are included
• No dependencies except a C++ compiler (however, -std=c++17 is enabled by default)

This folder contains a makefile, a src folder, a lib folder, and a tests folder. The directory build is generated when running the makefile. The src folder contains a simple main file, lib contains a hello world program written across multiple files, tests is where (optional) catch2 tests are stored, and the build folder is where objects and the executable will be created.

All source files should be created in the lib folder. To change the name of the executable or add library flags and locations, edit the variables at the very top of the makefile. However, if many dependencies are needed, consider using the more complete build system outlined below.

Prerequisistes:

• GNU Make
• A C++ compiler

Install both of these with your package manager. On ubuntu you can do this with sudo apt install build-essential

Usage:

Running

To run this boilerplate, simply cd into the directory minimal, run make, and then run build/bin/hello. Alternatively, run make run to build and run in one step.

Adding Dependencies

The general procedure is as follows:

1. Install your dependency. Whatever way you do this (package manager, build from source, etc.) make sure you find where it is installed.
2. In the makefile, add -l<library-name> to the variable EXT_LIBS
3. Next, add -I/path/to/library/headers to the variable INCLUDES
4. At this point, try to run your program with make run, as this may be all you need. If your code can now use the new library, you're done. Otherwise move on to the next step.
5. In the makefile, add -L/path/to/library/libfiles to the variable EXT_LIB_DIRS. This is not always necessary, as libraries installed with the package manager usually get placed in a path that the compiler already searches. However, this is necessary if, for instance, you build something from source and install it to a custom location.

This procedure can be made much easier by using the program pkg-config. It automatically finds the location of many libraries and generates the flags needed to pass to the compiler. For instance, suppose you just installed libcrypto. To find the flags you need with pkg-config, follow these instructions:

1. Run pkg-config --libs-only-l libcrypto. The output of this command is what you need to add to EXT_LIBS in the makefile.
2. Run pkg-config --libs-only-L libcrypto (note the capital L). The output of this command is what you need to add to EXT_LIBS_DIRS in the makefile. This output might be empty. If so, do nothing to EXT_LIBS_DIRS.
3. Run pkg-config --cflags libcrypto. The output of this command is what you need to add to INCLUDES in the makefile. This output might be empty. If so, do nothing to INCLUDES.

Testing

In order for testing to work, we assume you have Catch2 installed. Use your package manager to find this, e.g. apt search catch2, dnf search catch2, zypper se catch2, etc.

After that, run make tests, as it should work out of the box. If not, make sure catch2 is installed to a "standard" location like /usr/include.

Full Build System

This folder uses Conan for dependency resolution and build management. All features are available from the command line, but it also integrates nicely with JetBrains's CLion IDE if you install the conan plugin.

Prerequisites:

• CMake (install with your distro's package manager: sudo apt install cmake or similar)
• conan.

Features:

• Only recompiles what is changed
• Very easy to use, no messing with CMakeList.txt or makefile files.
• Dependencies are easy with package management by conan

All sources are in the src directory. No build directory exists by default, but I recommend (and the .gitignore expects) you to name it 'build'. If you add source files, add their names to the variable sourcesList in the file CMakeLists.txt. There you may also change the name of your project or executable.

The real beauty of Conan is how easy it is to add dependencies. You don't have to worry about where they're stored or dependencies-of-dependencies. You simply add whatever library you want to conanfile.txt and conan will automatically grab it and its transitive dependencies.

Usage:

Running

To run your program, first make a build directory and switch to it: mkdir build && cd build. Next, run the following commands in that build directory:

1. conan install ..
2. cmake .. -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release
3. cmake --build .

After that, run your program with bin/hello.

Once you've run each of those commands once, you can rebuild your program by only running cmake --build . in your project build directory, as long as your dependencies haven't changed.

Adding Dependencies

To add dependencies, do the following:

1. Search for your package on conan center. If it isn't there, you'll have to figure something else out. Maybe search for 'conan ' on the web. You may have to use another build system.
2. Assuming you found your package, copy the name and version (ex. openssl/1.1.1i) to your clipboard
3. Paste that string on a new line in the [requires] section of conanfile.txt
4. Re-run all build steps described above.

Testing

When following the instructions described in the section 'Running', both the main executable and the testing executable are generated. Simply run bin/hello-test from the build directory.