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Comment by phendrenad2 | Hacker News Reader

...You've just discovered why interfaces like COM and Cocoa are a good idea, yes. Welcome to 1999. Join me in cursing the proliferation of POSIX and FFIs. JOIN ME.

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Win32 API is another example of something that has been pretty stable… But then, it is basically C. (Just like COM is basically C++.)

COM was meant to be language-agnostic, so I don't see how it's basically C++...

COM can also be seen as a mapping of C++ APIs (with some extras like interface versioning) onto C APIs, mainly as workaround for C++'s missing ABI stability (so that C++ APIs can be exposed via DLLs in a (C++) compiler-agnostic way).

Interfaces are made to match the C++ vtable. Using them from C, for example, is somewhat of a hassle. (Not to say anything about IDL…)

Not exactly. They use a different calling convention (for systems where 'this' pointers are normally passed in a special place) from usual C++ classes to match C-ish, and there's a few other restrictions for things (overloads, inheritance) that otherwise differ across C++ ABIs and wouldn't map well to other non-C++ languages.

The C wrappers generated by MIDL are also fairly similar to raw C++, compare (where pUnk is an IUnk *):

    pUnk->Something(&bA);

with...

    IUnk_Something(pUnk, &bA);

which expands to something like this:

    pUnk->lpVtbl->Something(pUnk, &bA);

Win32 API is frozen in Windows XP timeframe, no wonder it is stable, all major new APIs since Longhorn failure are based in COM.

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