Show HN: Curious Namespace Trick – Limited static polymorphism in C++

I agree... if I see an `#if defined _WIN32` I know what I'm looking at, but this trick would be a complete surprise.

It is. The page starts with talk about namespaces and such, so one thinks this will be about some cool new features of C++11, but instead ends with a global #define.

Yes, coding like this is evil and will eat your hamster. For example, trying to have a variable named "platform" will break your code in strange ways. And before you say "but it's C++, it's modern", CppCoreGuidelines explicitly say this is bad and that one should favor #ifdefs. (https://github.com/isocpp/CppCoreGuidelines/blob/master/CppC...)

Yes! The problem is, alternative implementations are also meta-programming tricks! Template meta-programming techniques like 'C++ Traits' and 'Curiously recurring template pattern'. Both are being used in the performance-critical places by the way (think Eigen library, etc).

Is there some other alternative that allows 'compile-time static overrides' with relatively clean syntax?

author The other alternative, which is currently used in production to solve the same problem is CRTP ( https://en.wikipedia.org/wiki/Curiously_recurring_template_p... ) ... And the question is, which one is a lesser evil.

From the page:

"This technique is an alternative to weak linking,..."

No, the post says "or C-style code", which is presumably just C++ when you aren't using classes or templates or something like that.

OK we took out the "C/" bit above.