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C++

Multilingual benchmarking project => Bazel for advanced engineering

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In her one year, Molly saw many more exciting places than I did until I was about 28. She does pretty well :-D

When working on performance experiments across C++ and Go, you obviously need a multilingual project structure. There were two paths forward: create separate build systems under a shared repository, or consolidate everything under a single, coherent framework. Bazel made that decision easy.

Using Bazel to unify builds isn’t just convenient—it should be the default choice for any serious engineering effort that involves multiple languages. It eliminates the friction of managing isolated tools, brings deterministic builds, and handles dependencies, benchmarking, and cross-language coordination with minimal ceremony.

Here’s why Bazel makes sense for performance-critical, multilingual projects like this one—no fragile tooling, no redundant setups, just clean integration that scales.

Functional Programming style in C++

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Teskey-Torpok Pass is a lovely pass leading you to Song-Kol Lake, Naryn region.

I’ve been on a bit of a Leetcode streak lately, poking at problems from companies I secretly admire. To keep things interesting (and to avoid nodding off in front of the screen), I challenged myself to solve the same task three ways: good old C++, its shiny modern C++20 cousin, and Elixir. It turns out that staring at a problem through a functional programming lens is like putting on X-ray specs—you see the same lines of code, but suddenly, there’s a weird beauty in that filter chain.<

My first pass was as traditional as it gets—a simple C++ class with an array and a loop. No magic here, just pushing timestamps and scanning them one by one. The implementation is pretty naive, but considering the constraints provided by the Design a hit counter challenge, even an unscalable approach is acceptable. So, we will push all new timestamps into the std::queue std::vector and then simply count.

Fixing C++ lacks switches on strings

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Birch Grove is just 40 minutes from Bishkek. Although I was concerned about the strong, foggy weather, it was an amazing opportunity for photography!

C++ is a powerful language, and I genuinely love it, but sometimes, even in modern versions, it lacks some surprisingly simple features. One such missing feature is switch on std::string. You’d think that by now, we could use a switch statement on strings just like we do with integers or enums—after all, Go has it! But no, C++ keeps us on our toes.

Why Doesn’t C++ Support switch on strings? Because "you only pay for what you use," which is the standard C++ mantra. The switch statement in C++ relies on integral types. Under the hood, it works by converting the case values into jump table indices for efficient execution. But std::string (or even std::string_view) is not an integral type—it’s a more complex data structure. That’s why you can’t simply do:

switch (msg->get_value<std::string>()) { // Nope, not possible :-(
    case "topology":
        // Handle network topology
        break;
    case "broadcast":
        // Handle network broadcast
        break;
}

How to compile C++ in 2025. Bazel or CMake?

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Today, we’re examining two modern build systems for C++: CMake, the industry favorite, and Bazel, a powerful alternative. While CMake is often the default choice, I believe that approach warrants a bit more scrutiny—after all, we’re focusing on modern tools here (yep, not counting Make, right?). To explore this, I’ve created a practical demo project showcasing how both systems manage a real-world scenario.

Using the maelstrom-challenges project as a starting point, I’ve extracted a C++ library called maelstrom-node. This library has been set up to work seamlessly with both Bazel and CMake, giving us a hands-on comparison of their approaches, strengths, and quirks.

The Project Structure

Here’s what the final directory layout for maelstrom-node looks like:

Managing Multi-Language Projects with Bazel

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In today’s software development landscape, it’s rare to encounter a project built with just one programming language or platform. Modern applications often require integrating multiple technologies to meet diverse requirements. This complexity is both a challenge and an opportunity, demanding robust tools to manage dependencies, builds, and integrations seamlessly. Bazel, a powerful build system, is one such tool that has proven invaluable for multi-language projects.

Recently, I decided to extend my Maelstrom challenges with a C++-based test to explore how Bazel can simplify managing multi-language dependencies and streamline development workflows.

Why Bazel for Multi-Language Projects?

Bazel’s design philosophy emphasizes performance and scalability, making it an excellent choice for projects that involve multiple languages. With its support for Bazel modules, adding dependencies is as simple as declaring them in a MODULE.bazel file. For example, integrating the popular logging library spdlog is straightforward:

Returning to Rust: A Journey Through Tooling, Performance

When I started tackling the Maelstrom challenges, my initial thought was to use C++. It’s a language I know inside out, and its performance is hard to beat. However, as I contemplated setting up the project, I realized I couldn’t justify fighting with the C++ pipeline for free. Crafting a proper CMake or Bazel configuration might be worthwhile for large-scale projects or when compensated, but for personal experiments? It’s an unnecessary headache.

Why Go is My Default Choice

For most non-performance critical scenarios, Go is my default, no-brainer choice. It has a clean build system, excellent tooling, and a developer experience that doesn’t make me dread the setup process. Go’s simplicity allows me (and any level team) to focus on solving the problem rather than wrestling with the environment. Yet, this time, I decided to take a different path.