C++ Quickstart

Note: this Quickstart uses Bazel version 7.0 or higher as the official build system for Abseil, which is supported on most major platforms (Linux, Windows, macOS, for example) and compilers.

This document is designed to allow you to get the Abseil development environment up and running. We recommend that each person starting development with Abseil code at least run through this quick tutorial.

Abseil also supports building with CMake. For information, please see the CMake Quickstart.

Prerequisites

Running the Abseil code within this tutorial requires:

  • A compatible platform (e.g. Windows, macOS, Linux, etc.). Most platforms are fully supported. Consult the Platforms Guide for more information.
  • A compatible C++ compiler supporting at least C++17. Most major compilers are supported.

Although you are free to use your own build system, most of the documentation within this guide will assume you are using Bazel.

To download and install Bazel (and any of its dependencies), consult the Bazel Installation Guide.

Set Up a Bazel Workspace to Work with Abseil

A Bazel workspace is a directory on your filesystem that contains the source files for the software you want to build. Each workspace directory has a text file named MODULE.bazel which may be empty, or may contain references to external dependencies required to build the outputs.

First, set up your development directory:

mkdir my_workspace && cd my_workspace

As of Bazel 7.0, the recommended way to consume Abseil is through the Bazel Central Registry. To do this, create a MODULE.bazel file in the root directory of your Bazel workspace with the following content:

# MODULE.bazel

# Choose the most recent version available at
# https://registry.bazel.build/modules/abseil-cpp.
bazel_dep(name = "abseil-cpp", version = "20240116.0")

This will bring in Abseil along with all of its dependencies into your new Bazel workspace.

Creating and Running a Binary

Now that you’ve setup a Bazel workspace with Abseil as a dependency, you’re ready to use it within your own project.

In this example, we will create a hello_world.cc C++ file within your Bazel workspace directory:

#include <iostream>
#include <string>
#include <vector>

#include "absl/strings/str_join.h"

int main() {
  std::vector<std::string> v = {"foo", "bar", "baz"};
  std::string s = absl::StrJoin(v, "-");

  std::cout << "Joined string: " << s << "\n";

  return 0;
}

Note that we include an Abseil header file using the absl prefix.

Creating Your BUILD.bazel file

Now, create a BUILD.bazel file with a cc_binary rule in the same directory as your hello_world.cc file:

cc_binary(
  name = "hello_world",
  deps = ["@abseil-cpp//absl/strings"],
  srcs = ["hello_world.cc"],
)

We declare a dependency on the Abseil strings library (@abseil-cpp//absl/strings) using the prefix we declared in our MODULE.bazel file (@abseil-cpp).

For more information on how to create Bazel BUILD.bazel files, consult the Bazel Tutorial.

Build our target (hello_world) and run it:

$ bazel build //:hello_world
INFO: Analysed target //:hello_world (12 packages loaded).
INFO: Found 1 target...
Target //:hello_world up-to-date:
  bazel-bin/hello_world
INFO: Elapsed time: 0.180s, Critical Path: 0.00s
INFO: Build completed successfully, 1 total action

$ bazel run //:hello_world
INFO: Running command line: bazel-bin/hello_world
Joined string: foo-bar-baz

Congratulations! You’ve created your first binary using Abseil code. If you want to see a full, working example of code using Abseil, see the bazel-hello directory in the abseil-hello repository.

What’s Next