Set Up Your Toolchain

You need two things to take this course: a C++ compiler that supports C++17, and a text editor. That is all. There is no build system to learn, no framework to install, and nothing to configure.

Pick the route that matches your machine, then run the verification at the end of this page before moving on.

The only command the course uses

g++ -std=c++17 -Wall -Wextra your_file.cpp -o your_file

• -std=c++17 — compile as C++17, the standard this course is written in.
• -Wall -Wextra — turn on the useful warnings, so the compiler tells you about suspicious code before it becomes a bug.
• Everything the course says about a program's behaviour assumes these flags. Using them means what you see matches what the author saw.

---

Route A — Windows

A1. WSL (recommended)

Windows Subsystem for Linux gives you a real Linux toolchain with one command, and it behaves identically to the instructions used throughout this course.

1. Open PowerShell as Administrator and run:

wsl --install

1. Restart when prompted. Ubuntu opens and asks for a username and password.
2. Inside Ubuntu, install the compiler:

sudo apt update
sudo apt install -y build-essential

1. Your course files should live on the Linux side for speed — for example in ~/oop-course. You can still open them from Windows editors; see Editor setup below.

A2. MSYS2 (native Windows toolchain, no Linux)

Prefer to stay entirely inside Windows? Use MSYS2.

1. Install MSYS2 from the official site, https://www.msys2.org.
2. Open the MSYS2 UCRT64 shell (not the plain MSYS2 shell) and run:

pacman -Syu

Close and reopen the shell if it asks you to. 3. Install the compiler:

pacman -S --needed base-devel mingw-w64-ucrt-x86_64-gcc

1. Add C:\msys64\ucrt64\bin to your PATH environment variable, so g++ works from any terminal — including PowerShell and the VS Code terminal.
2. Close and reopen every terminal window afterwards.

A3. Single-folder compiler bundles

If you want neither WSL nor a package manager, standalone bundles such as w64devkit or the MinGW-w64 builds from WinLibs give you g++ in one folder. Unzip it, add its bin directory to PATH, and you are done.

A4. Visual Studio (MSVC) — an alternative, not the course default

Microsoft's compiler works perfectly well, but its command line differs from the one used in this course. If you use it, the equivalent build is:

cl /std:c++17 /W4 /EHsc your_file.cpp

Keep the standard flag /std:c++17; without it, older Visual Studio versions default to an older C++ standard and some course examples will not compile.

One toolchain, not several

Mixing compilers is the most common cause of confusing errors. Pick one route — WSL or MSYS2 or MSVC — and stay with it for the whole course.

---

Route B — Linux

Use your distribution's package manager. The package that contains g++ along with the other basic build tools is build-essential on Debian and Ubuntu:

sudo apt update
sudo apt install -y build-essential

Other distributions:

Distribution	Command
Fedora / RHEL	sudo dnf install -y gcc-c++
Arch / Manjaro	sudo pacman -S --needed gcc
openSUSE	sudo zypper install -y gcc-c++
Alpine	sudo apk add build-base

---

Route C — macOS

Apple's command-line developer tools include Clang, which compiles C++17 fine:

xcode-select --install

On macOS, g++ is Clang

macOS does not ship GNU g++. The g++ command is a small alias that calls Apple's Clang instead. That is fine — the course's compile command works unchanged — but do not be surprised when g++ --version reports an Apple clang version rather than a GCC version.

If you specifically want GNU GCC (some compiler messages differ), install it with Homebrew: brew install gcc, then use g++-14 or whichever version it reports.

---

Route D — No installation at all (online compilers)

You can complete most of the modules using only a browser. These sites compile and run C++:

Site	Notes
Compiler Explorer — https://godbolt.org	The best choice for understanding code: it shows the generated assembly next to your source. Set the compiler to a recent GCC or Clang and the standard to C++17.
Wandbox — https://wandbox.org	Clean, fast, supports many compiler versions.
OnlineGDB — https://www.onlinegdb.com/online_c++_compiler	Includes a debugger you can step through.
Programiz — https://www.programiz.com/cpp-programming/online-compiler	Beginner-friendly interface.

Important limitations. Online compilers:

• usually do not let you choose an older or newer standard cleanly, so make sure C++17 is selected;
• often do not support file input/output that persists, which matters from Module 16 onwards;
• cannot use sanitizers, which the course uses to demonstrate memory bugs in Modules 10 and 11.

Use an online compiler when you are stuck on a machine without a toolchain, but install a local compiler before the labs that involve files or memory.

---

Editor setup

Any editor works — even Notepad will compile the course's examples. For a comfortable experience without a heavy IDE, VS Code with the official C/C++ extension is a good default: it gives you syntax highlighting, inline compiler messages, and F5 to build and run.

To make VS Code use exactly the course's compile command, create .vscode/tasks.json in your own project folder (not in this repository) with:

{
  "version": "2.0.0",
  "tasks": [
    {
      "label": "Compile (course flags)",
      "type": "shell",
      "command": "g++",
      "args": ["-std=c++17", "-Wall", "-Wextra", "${file}", "-o", "${fileDirname}/${fileBasenameNoExtension}"],
      "group": { "kind": "build", "isDefault": true },
      "problemMatcher": ["$gcc"]
    }
  ]
}

On Windows with MSYS2, if your editor cannot find g++, give the full path in "command", for example C:\\msys64\\ucrt64\\bin\\g++.exe.

Where to keep your own files

Do not work inside the repository's examples/ folder — you would end up editing the course's reference copies. Create your own folder, for example ~/cpp-practice/, or use the scratch/ folder at the repository root, which is already excluded from version control.

---

Verify your setup

Run these three commands. All three must succeed before you continue.

g++ --version

You should see a version banner. If it says command not found on Linux/macOS, or is not recognized on Windows, your PATH is not set — go back to your route above.

g++ -std=c++17 -Wall -Wextra -x c++ - -o /tmp/check && /tmp/check

Type the following, then press Ctrl+D (Linux/macOS) to end input:

#include <iostream>
int main() { std::cout << "toolchain ok\n"; }

Expected output:

toolchain ok

On Windows, replace /tmp/check with check.exe and run check.exe.

Then confirm your editor can save a .cpp file with LF line endings — if you cloned the repository, its .editorconfig sets this automatically in most editors. CRLF line endings are harmless to the compiler, but they make your file differ from every other file in the course for no reason, and they produce noisy diffs the moment you keep your own work in version control.

---

Troubleshooting

Symptom	Cause	Fix
g++: command not found (Linux/macOS)	Compiler not installed, or not on PATH	Install it via your package manager; reopen the terminal
'g++' is not recognized... (Windows)	PATH does not include the compiler's bin folder	Add it, then reopen the terminal (changes to PATH do not affect open windows)
unrecognized command line option '-std=c++17'	The compiler is too old to understand the C++17 flag	Install a newer GCC. GCC 9 or newer is the practical recommendation for this course
fatal error: iostream: No such file or directory	You are compiling a C++ file with the C compiler	Use g++, not gcc
permission denied: ./hello	Missing execute permission	chmod +x ./hello
cannot execute binary file	You are running a file built for another platform	Rebuild with your own compiler
Command runs but nothing happens	On Windows you may need hello.exe	Run hello.exe, or ./hello.exe in Git Bash
Build succeeds, then Segmentation fault	A runtime bug, not a setup problem	This is exactly what Modules 10 and 11 are about — carry on

---

Next: Your First Program