Running C++23 Code on Windows 95: A Technical Feat

Running software written with the latest language features on obsolete hardware presents a significant technical hurdle. The concept involves taking advantage of C++23 capabilities—such as modules, lambdas, and constexpr—and forcing them to operate within the severe constraints of a Windows 95 environment. This environment lacks the robust support systems found in modern operating systems.

The primary obstacle is the absence of a modern standard library. On a standard Windows 95 installation, there are no dynamic link libraries (DLLs) that support the features required by C++23. Therefore, the code must be self-contained. The demonstration proves that with the right settings, the compiler can generate code that does not rely on external runtime dependencies that simply do not exist on the target system.

The setup begins with Visual Studio 2022, a modern Integrated Development Environment (IDE). To target the legacy system, the compiler must be configured to generate 32-bit x86 machine code. However, the most critical adjustments involve what is excluded from the build.

The process requires disabling two major components:

• Exceptions: The try/catch mechanism is turned off to avoid linking against the exception handling runtime.
• Standard Library: The inclusion of standard headers like <string> or <vector> is removed to prevent automatic linking to the standard library.

These settings ensure the compiler produces the smallest possible binary without hidden dependencies.

Without the standard library, basic data structures must be rebuilt from scratch. The demonstration details the creation of a minimal implementation of std::string. This custom class manages memory manually, handling allocation and deallocation directly rather than relying on the default allocator.

Furthermore, custom allocators are designed to work with the WinAPI functions GlobalAlloc and GlobalFree. By writing these wrappers, the code can utilize the operating system's memory management directly. This allows the use of modern syntax and features like lambdas and constexpr while the underlying mechanics are tuned for the vintage architecture.

Once the code is written and the custom classes are in place, the final step is linking. Surprisingly, the demonstration utilizes a linker dating back to 1998. This specific tool is capable of producing an executable format compatible with Windows 95.

The resulting program runs successfully on a Pentium machine equipped with just 16 MB of RAM. This outcome demonstrates that the C++23 standard is flexible enough to support a unified codebase. Developers can theoretically write code once and, with the correct compilation flags and support libraries, deploy it to both cutting-edge systems and retro-computing enthusiasts.