CMake C++ Project Template

Division with a remainder library

Thank you for your interest in this project!

Are you just starting with CMake or C++?

Do you need some easy-to-use starting point, but one that has the basic moving parts you are likely going to need on any medium sized project?

Do you believe in test-driven development, or at the very lest — write your tests together with the feature code? If so you'd want to start your project pre-integrated with a good testing framework.

Divider is a minimal project that's kept deliberately very small. When you build it using CMake/make (see below) it generates:

1. A tiny static library lib/libdivision.a,
2. A command line binary bin/divider, which links with the library,
3. An executable unit test bin/divider_tests using Google Test library.
4. An optional BASH build script build-and-run that you can use to quickly test if the project compiles, and runs.

Usage

Prerequisites

You will need:

• A modern C/C++ compiler
• CMake 3.1+ installed (on a Mac, run brew install cmake)
• If you prefer to code in a great IDE, I highly recommend Jetbrains CLion. It is fully compatible with this project.

Building The Project

Git Clone

First we need to check out the git repo:

❯ mkdir ~/workspace
❯ cd ~/workspace
❯ git clone \
    https://github.com/kigster/cmake-project-template \
    my-project
❯ cd my-project
❯ bash build-and-run

The output of this script is rather long and is shown on this screenshot.

The script build-and-run is a short-cut — you shouldn't really be using this script to build your project, but see how to do it properly below.

Project Structure

There are three empty folders: lib, bin, and include. Those are populated by make install.

The rest should be obvious: src is the sources, and test is where we put our unit tests.

Now we can build this project, and below we show three separate ways to do so.

Building Manually

❯ rm -rf build && mkdir build
❯ cd build
❯ cmake ..
❯ make && make install
❯ cd ..

Running the tests

❯ bin/divider_tests
[==========] Running 5 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 5 tests from DividerTest
[ RUN      ] DividerTest.5_DivideBy_2
[       OK ] DividerTest.5_DivideBy_2 (1 ms)
[ RUN      ] DividerTest.9_DivideBy_3
[       OK ] DividerTest.9_DivideBy_3 (0 ms)
[ RUN      ] DividerTest.17_DivideBy_19
[       OK ] DividerTest.17_DivideBy_19 (0 ms)
[ RUN      ] DividerTest.Long_DivideBy_Long
[       OK ] DividerTest.Long_DivideBy_Long (0 ms)
[ RUN      ] DividerTest.DivisionByZero
[       OK ] DividerTest.DivisionByZero (0 ms)
[----------] 5 tests from DividerTest (1 ms total)

[----------] Global test environment tear-down
[==========] 5 tests from 1 test case ran. (1 ms total)
[  PASSED  ] 5 tests.

Running the CLI Executable

Without arguments, it prints out its usage:

❯ bin/divider

Divider © 2018 Monkey Claps Inc.

Usage:
	divider <numerator> <denominator>

Description:
	Computes the result of a fractional division,
	and reports both the result and the remainder.

But with arguments, it computes as expected the denominator:

❯ bin/divider 112443477 12309324

Divider © 2018 Monkey Claps Inc.

Division : 112443477 / 12309324 = 9
Remainder: 112443477 % 12309324 = 1659561

Building in CLion

NOTE: Since JetBrains software does not officially support git submodules, you must run git submodule init && git submodule update before starting CLion on a freshly checked-out repo.

NOTE: We recommend that you copy file .idea/workspace.xml.example into .idea/workspace.xml before starting CLion. It will provide a good starting point for your project's workspace.

Assuming you've done the above two steps, you can start CLion, and open the project's top level folder. CLion should automatically detect the top level CMakeLists.txt file and provide you with the full set of build targets.

Select menu option Build ➜ Build Project, and then Build ➜ Install.

The above screenshot is an example of CLion with this project open.

Using it as a C++ Library

We build a static library that, given a simple fraction will return the integer result of the division, and the remainder.

We can use it from C++ like so:

#include <iostream>
#include <division>

Fraction       f = Fraction{25, 7};
DivisionResult r = Division(f).divide();

std::cout << "Result of the division is " << r.division;
std::cout << "Remainder of the division is " << r.remainder;

File Locations

• src/* — C++ code that ultimately compiles into a library
• test/lib — C++ libraries used for tests (eg, Google Test)
• test/src — C++ test suite
• bin/, lib, include are all empty directories, until the make install install the project artifacts there.

Tests:

• A test folder with the automated tests and fixtures that mimics the directory structure of src.
• For every C++ file in src/A/B/<name>.cpp there is a corresponding test file test/A/B/<name>_test.cpp
• Tests compile into a single binary test/bin/runner that is run on a command line to run the tests.
• test/lib folder with a git submodule in test/lib/googletest, and possibly other libraries.

Contributing

Pull Requests are WELCOME! Please submit any fixes or improvements, and I promise to review it as soon as I can at the project URL:

• Project Github Home
• Submit Issues
• Pull Requests

License

© 2017-2019 Konstantin Gredeskoul.

Open sourced under MIT license, the terms of which can be read here — MIT License.

Acknowledgements

This project is a derivative of the CMake Tutorial, and is aimed at saving time for starting new projects in C++ that use CMake and GoogleTest.