Re: [boost] c++03 library survey

On 8/28/18 10:21 AM, degski via Boost wrote:

On Tue, 28 Aug 2018 at 19:06, Robert Ramey via Boost wrote:

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Actually, I think the the impact of move semantics on performance of well written existing code is minimal. On new code which uses more types as values it's helpful.

I don't think it has anything to do with whether the code is well written, copying a pointer f.e. is not the same as copying a whole array of data, because that could [should be] be the difference between move assignment and copy assignment.

right. One who is thinking about what he's doing is not going to copy a whole array of data if he's using C++03. But since C++11 makes it efficient, he may. So compiling C++03 code with a C++11 compiler isn't going to make a difference.

Of course if the library were written today, it would all the new stuff.

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I don't think it would be faster (unless it were made header only) but it would likely have have half the number of lines of code (or less).

Header only is of no interest, whatsoever, in terms of performance, that's not how things work (inlining could be affected, but that's about it, I would say)

LOL - inlining IS the essential difference with a header only library. It would eliminate one move in the serialization libary. And that would double the speed. This is why a C++11 serialization library (cereal) is twice as fast as boost serialization and other libraries.

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But the years long slog to address corner cases, workarounds for compiler bugs and standard library bugs, etc. And there would be design changes which would also create a bunch of ripple effects. So it would really end up as a whole re-write.

Yes, it's a major job, hence all the resentment.

It's not just resentment - there's just no benefit to it.

degski