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Comment by pjmlp | Hacker News Reader

This is a recent blog post from DirectX team,

https://devblogs.microsoft.com/directx/omm/

Compare the C++ code samples with the Modern C++ usually talked about C++ conferences.

This is why I keep saying I only see such high bar code on conference slides, and my hobby projects, those DirectX code samples are much more closer to daily C++ written in big corporations, ironically even those that are C++ compiler vendors with seats at WG21.

On the other hand, there are many industries where I don't see Rust taking anything meaningful away from either C or C++, regardless of how much we complain about them, or how much better Rust happens to be over them.

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Microsoft's DirectX C++ example code needs to interact with DirectX' C APIs. That will easily lead to "C with classes" C++ when most of the code is interacting with foreign APIs, like these API demos do.

I think open-source software like https://github.com/microsoft/WSL is probably more representative of what modern C++ companies look like. Plenty of files that just interact with OS C APIs, but no shortage of modern C++ features in use.

That is an excuse, there are modern C++ ways to interact with COM, as shown in C++/WinRT DirectX samples, or using WIL.

In what way does interact with C APIs become an argument to use alloca() with raw pointers?

Just recently I also submitted an issue on Azure C++ SDK regarding use of C style strings and arrays, what is the excuse there?

I would not call that example production quality code.

CreateFileA API thing is only available for compatibility with prehistoric software written for Win9x from the nineties. Also, the SDK comes with CAtlFile class which wraps CreateFileW / ReadFile / CloseHandle and guarantees closing handle in the destructor.

They are using a raw pointer in OMMSet structure which leaks memory. I would replace the raw pointer with std::unique_ptr<D3D12_RAYTRACING_OPACITY_MICROMAP_HISTOGRAM_ENTRY[]>

As for the _alloca, I think it’s OK however I usually assert() the size being allocated is reasonable, like under 256kb.

Examples provide the foundation for learning, when the examples are bad, people learn bad practices.

I think the correct modern way to use WinAPI is to set code page to utf8 in your app manifest, completely disregard W-APIs and only use A-APIs

I have never seen ATL used in production code but I have seen many "legacy" Win32 functions, including *A variants.

That particular class doesn’t depend on the COM-related pieces of the ATL library. It can be used in any C++ project which targets windows desktop platform. I think since VS2015 ATL is available even in the freeware community edition of the IDE. Before that, it required a commercial edition.

About non-Unicode WinAPI functions, I don’t use them at all in the software I’m developing, nor the TCHAR conditional typedef. VC++ compiler defines wchar_t as a built-in type for the UTF16 strings used in WinAPI functions.

> It can be used in any C++ project which targets windows desktop platform.

Any project which only targets Windows, or at least it can only be used in Windows-specific code. Even if you currently only target Windows, baking platform-specific types into your core is foolish.

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