Is the C++ preprocessor still needed?

Re:Is the C++ preprocessor still needed? by Negitivefrags on Wednesday May 10, 2017 @02:26AM (#14306287)

I wouldn't say C++ is fine with it. vector<bool> is widely viewed as a mistake. I would actually say it's one of the few inconsistencies in a standard library that tends to be very consistent.

The problem is that (quite rightly) the C++ standard committee tries very hard to not break existing code. There isn't really an easy way to deprecate a specialization of this container without causing 32x more memory use if someone was relying on it, and even worse it would be a silent breaking change.

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Re:Is the C++ preprocessor still needed? by Manishearth on Wednesday May 10, 2017 @08:18PM (#14312922)

I mean, this isn't the only case of broken parametricity I've come across in C++ codebases. Though it's the only one in the stdlib.

I know vector<bool> is controversial (and I understand it can't be "fixed" now), I was just surprised that something breaking parametricity so blatantly was ever agreed upon in the first place -- in more functional languages parametricity is kinda much more jealously guarded. Bit of a culture shock there, is all :)

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Re:Is the C++ preprocessor still needed? by marvy on Wednesday May 10, 2017 @11:59AM (#14309219)

You mean 8x more memory, right?

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