How can you make your C++ code portable across operating systems?

On Desktop, most commonly we use windows or Linux. In this case we use only standard C++ libraries and templates. The major problem of porting code appears in embedded systems (SoCs) with different RTOS. Each RTOS has different system calls for same functionality. Although advanced C++ standard 11 or higher solves lot of problems for embedded systems, still the system calls porting problem cannot be solved. What I do to deal with this problem, defined my own system calls then map them with different RTOS system calls and group them under different macros for each RTOS. Enable one of RTOS macro.

Split your code into modules that can be reused across different operating system. Separate OS-specific code from the cross-platform one and use pre-processor directives and defines to compile it or not. Use standard C++ features and cross-platform libraries. If you use the same functionality on multiple operating systems, but the API differs, try to define wrapper functions / classes and implement them differently for each OS. Use the wrappers to achieve the logic of your application. Use encapsulation, design patterns and OOP programming to define the backbone of your app. Test the code on all platforms where it will be deployed. Use dynamic runtime testing tools (like Valgrind, Dr. Memory, dtrace, ...) to identify issues.

C++ is quicker than Python because it is statically typed, which results in faster code compilation. Python is slower than C++ because it enables dynamic type and utilizes an interpreter, which slows down compilation.

In my experience, I've found that prioritizing standard C++ features is pivotal for code portability, and the C++ standards, (encompassing the library, template, and algorithms) ensures compatibility across diverse compilers and platforms. In my case, adopting these features gave me a solid foundation, minimizing the reliance on common non-standard elements like compiler-specific extensions or platform-centric libraries. This not only enhances code consistency but also mitigates potential compatibility issues when transitioning between operating systems. By adhering to the C++ standard, developers like me can pave the way for seamless execution and maintainability across the varied landscape of Windows, Linux, and Mac OS.

For example, another way to make C++ code portable is to use libraries and tools designed to work across platforms, such as Qt, wx, Widgets, CMake, and GCC. These libraries and tools provide common functionality and abstractions that hide small details and platform-specific differences.

Navigating platform intricacies is a captivating challenge in my extensive experience. Conditional compilation, using #ifdef, #ifndef, and #endif, is a powerful ally for handling variations in features like system calls, file paths, or data types across platforms. This allows selective code inclusion/exclusion based on predefined macros, crafting adaptive code. #define directives add flexibility by creating custom macros. This strategic use tailors C++ code, ensuring seamless execution in diverse environments. From my perspective, this enhances code versatility and streamlines managing platform intricacies, contributing to an efficient development process. Once you know the most common C++ techniques deeper, it gets “easier”…

I'll suggest an alternative. Leverage the compiler's optimizer to remove dead code, and use language if/then and virtual function calls around platform-dependent code. That way, the compiler does type checking in all paths regardless of what platform you are compiling for.

Conditional compilation is a powerful technique in C++ that enables developers to write code that adapts to different platforms or environments. It's incredibly useful when dealing with features that might not be universally supported or where variations exist across different systems.

In my experience, cross-platform libraries like Boost, Qt, wxWidgets, CMake, and GCC ensure C++ code portability. These frameworks are a great solution, providing common functionality and abstractions for platform-specific details. I like Boost for its portable libraries, for tasks from networking to filesystem, threading, and testing. Also, Qt and wxWidgets because of cross-platform graphical user interface frameworks, allowing creation of applications with a native look and feel. And cross-platform build systems and compilers like CMake and GCC streamlines code compilation and linking on different platforms. For me simplifies development and enhances the adaptability of C++ code across various operating systems.

By utilizing these cross-platform libraries and tools, developers can create robust, portable C++ applications that can be deployed across a wide range of platforms with minimal modification.

Some benefits are: Abstraction of Platform-Specific Details: These libraries and tools abstract away the complexities of different platforms, providing a unified interface for developers. Consistent Functionality: They offer consistent functionality regardless of the underlying operating system, ensuring that the code behaves similarly across platforms. Ease of Development: Developers can focus on writing code without worrying about low-level platform intricacies, improving productivity and reducing development time.

I would like to exemplify frameworks that provide a cross-platform API making development and distribution much easier depending on licensing requirements. The Qt framework is just one example of a cross-platform C++ effort. It has carried projects like KDE to many platforms and operating systems.

Include cross-platform C++ libraries and tools portable on multiple desired platforms. the libraries and tools helps the code to be compiled and executed on the platforms.

Building your project on different platforms, means different operating systems, and possibly different CPU architectures. It means that you have not just conditional compilation of code, but also may have different compilers. On each platform, not all your code is covered, and it is also built differently. Having reliable testing is essential if you want release high quality product. To cover the functionality on all platforms, need to have machines in all combinations that you are targeting. It can be on-prem physical machines or VMs, or in the cloud. Your testing shall be automated, and CI/CD comes here as must to aid deploying the software on all the platforms where you plan do the testing, so each build will be consistently tested.

When you use external components like Boost, Qt, wxWidgets, CMake, and GCC ,you need to make sure your product is maintained/updated with the newer versions. Never use modified , local versions of external components. It creates a maintenance nightmare.

Leverage static analysis and compiler warnings, to catch as many issues as possible. It is easier to catch portability issues as early as possible in the development process.

Embracing adaptability in coding has been part of my journey. Whether diving into intricate platform nuances, and leveraging robust frameworks like Boost and Qt, or streamlining with CMake and GCC, each experience highlights the importance of flexibility in the ever-evolving landscape of software development. And remember, tomorrow when you wake up, somebody created something new, so keep yourself updated please… I check the “news” every morning during my daily coffee. Cheers!