Tutorial: Install and use packages with vcpkg

This tutorial shows you how to create a C++ "Hello World" program that uses the fmt library with CMake and vcpkg. You'll install dependencies, configure, build, and run a simple application.

Prerequisites

Note

For Windows users, Visual Studio's MSVC (Microsoft Visual C++ Compiler) is the required compiler for C++ development.

1 - Set up vcpkg

  1. Clone the repository

    The first step is to clone the vcpkg repository from GitHub. The repository contains scripts to acquire the vcpkg executable and a registry of curated open-source libraries maintained by the vcpkg community. To do this, run:

    git clone https://github.com/microsoft/vcpkg.git
    

    The vcpkg curated registry is a set of over 2,000 open-source libraries. These libraries have been validated by vcpkg's continuous integration pipelines to work together. While the vcpkg repository does not contain the source code for these libraries, it holds recipes and metadata to build and install them in your system.

  2. Run the bootstrap script

    Now that you have cloned the vcpkg repository, navigate to the vcpkg directory and execute the bootstrap script:

    cd vcpkg && bootstrap-vcpkg.bat
    
    cd vcpkg; .\bootstrap-vcpkg.bat
    
    cd vcpkg && ./bootstrap-vcpkg.sh
    

    The bootstrap script performs prerequisite checks and downloads the vcpkg executable.

    That's it! vcpkg is set up and ready to use.

2 - Set up the project

  1. Configure the VCPKG_ROOT environment variable.

    export VCPKG_ROOT=/path/to/vcpkg
    export PATH=$VCPKG_ROOT:$PATH
    

    Note

    Setting the VCPKG_ROOT environment variable using the export command only affects the current shell session. To make this change permanent across sessions, you'll need to add the export command to your shell's profile script (e.g., ~/.bashrc or ~/.zshrc).

    set VCPKG_ROOT="C:\path\to\vcpkg"
    set PATH=%VCPKG_ROOT%;%PATH%
    

    Note

    Setting the VCPKG_ROOT environment variable using the set command only affects the current shell session. To make this change permanent across sessions, you can use the setx command and restart the shell session.

    $env:VCPKG_ROOT = "C:\path\to\vcpkg"
    $env:PATH = "$env:VCPKG_ROOT;$env:PATH"
    

    Note

    Setting the VCPKG_ROOT and updating the PATH environment variables in this manner only affects the current PowerShell session. To make these changes permanent across all sessions, you should add them to your PowerShell profile or set them through the Windows System Environment Variables panel.

    Setting VCPKG_ROOT tells vcpkg where your vcpkg instance is located. Adding it to PATH ensures you can run vcpkg commands directly from the shell.

  2. Create the project directory.

    mkdir helloworld && cd helloworld
    

3 - Add dependencies and project files

  1. Create the manifest file and add the fmt dependency.

    First, create a manifest file (vcpkg.json) in your project's directory by running the vcpkg new command from within the helloworld directory:

    vcpkg new --application
    

    Next, add the fmt dependency:

    vcpkg add port fmt
    

    Your vcpkg.json should look like this:

    {
        "dependencies": [
            "fmt"
        ]
    }
    

    This is your manifest file. vcpkg reads the manifest file to learn what dependencies to install and integrates with CMake to provide the dependencies required by your project.

    The default vcpkg-configuration.json file introduces baseline constraints, specifying the minimum versions of dependencies that your project should use. While modifying this file is beyond the scope of this tutorial, it plays a crucial role in defining version constraints for your project's dependencies. Therefore, even though it's not strictly necessary for this tutorial, it's a good practice to add vcpkg-configuration.json to your source control to ensure version consistency across different development environments.

  2. Create the project files.

    Create the CMakeLists.txt file with the following content:

    cmake_minimum_required(VERSION 3.10)
    
    project(HelloWorld)
    
    find_package(fmt CONFIG REQUIRED)
    
    add_executable(HelloWorld helloworld.cpp)
    
    target_link_libraries(HelloWorld PRIVATE fmt::fmt)
    

    Now, let's break down what each line in the CMakeLists.txt file does:

    • cmake_minimum_required(VERSION 3.10): Specifies that the minimum version of CMake required to build the project is 3.10. If the version of CMake installed on your system is lower than this, an error will be generated.
    • project(HelloWorld): Sets the name of the project to "HelloWorld."
    • find_package(fmt CONFIG REQUIRED): Looks for the fmt library using its CMake configuration file. The REQUIRED keyword ensures that an error is generated if the package is not found.
    • add_executable(HelloWorld main.cpp): Adds an executable target named "HelloWorld," built from the source file main.cpp.
    • target_link_libraries(HelloWorld PRIVATE fmt::fmt): Specifies that the HelloWorld executable should link against the fmt library. The PRIVATE keyword indicates that fmt is only needed for building HelloWorld and should not propagate to other dependent projects.

    Create the main.cpp file with the following content:

    #include <fmt/core.h>
    
    int main()
    {
        fmt::print("Hello World!\n");
        return 0;
    }
    

    In this main.cpp file, the <fmt/core.h> header is included for using the fmt library. The main() function then calls fmt::print() to output the "Hello World!" message to the console.

4 - Build and run the project

  1. Run CMake configuration

    To allow the CMake project system to recognize C++ libraries provided by vcpkg, you'll need to provide the vcpkg.cmake toolchain file. To automate this, create a CMakePresets.json file in the "helloworld" directory with the following content:

    {
      "version": 2,
      "configurePresets": [
        {
          "name": "default",
          "generator": "Ninja",
          "binaryDir": "${sourceDir}/build",
          "cacheVariables": {
            "CMAKE_TOOLCHAIN_FILE": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake"
          }
        }
      ]
    }
    

    This CMakePresets.json file contains a single "default" preset for CMake and sets the CMAKE_TOOLCHAIN_FILE variable. The CMAKE_TOOLCHAIN_FILE allows the CMake project system to recognize C++ libraries provided by vcpkg. Adding the CMakePresets.json automates the process of specifying the toolchain when running CMake.

    Configure the build using CMake:

    cmake --preset=default
    
  2. Build the project

    Run:

    cmake --build build
    
  3. Run the application

    Finally, run the executable to see your application in action:

    ./build/HelloWorld
    
    Hello World!
    
    .\build\HelloWorld.exe
    
    Hello World!
    

Next steps

To learn more about vcpkg.json, see our reference documentation: