Survey results: Your “top five” ISO C++ feature proposals

Today I collated and analyzed the results of the survey I posted two weeks ago.

I presented you with a daunting unsorted list of ~300 eye-numbing paper titles, and still 289 of you responded with ~1,200 total votes (not everyone picked five things) many of which contained thoughtful “how I would use it” verbatims. Thank you for your time and interest!

In addition to summing your votes per-paper, I also spent several hours manually assigning categories to the individual proposals so that we could see votes per-feature area. For example, “pattern matching” had multiple papers, so I wanted to generate a subtotal also for votes for “all pattern-matching papers” as well as for each of the individual ones. You might assign categories differently than I did, but I think these are a good start to see basic groupings and patterns.

Here’s a 35-page PDF of the full results. The following are some highlights.

The top-voted primary topic categories correlate well with the results we saw in the 2019 global C++ developer survey open-ended write-in questions for ‘if you could change one thing about C++’ and ‘any other feedback.’ The top topic areas are:

Primary topic category
#votes

Reflection

154

Convenience/usability

129

Error handling

129

Compile-time programming

105

Pattern matching

73

Concurrency

70

Performance

58

Numeric

47

Systems programming

45

Here’s a partial graph:

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The top-voted individual papers were:

Paper

#votes
P0707 reflection & metaclasses
89

P0709 error handling, static EH

85

P1371 pattern matching

71

P1240 reflection

40

P0323 error handling,
std::expected

24

P1767 package mgmt

23

P1485 coroutine keywords

23

P1750 std::process

22
P1717 compile-time programming
22
? no specific paper (a catchall when the response was useful and fit in a category, but didn’t include a specific paper number) 22
P1629 Unicode

20

P1031 low level file I/O

19

P1040 compile-time data embed

19

P0645 text formatting

16

P1729 text formatting

15

Finally, disclaimers:

Experimental: This was advertised as an experiment. The results may not be representative. However, as I mentioned already, the top-voted topic areas correlate well with the results from the 2019 global C++ developer survey open-ended write-in questions for ‘if you could change one thing about C++’ and ‘any other feedback.’Bias: I posted the poll on my personal blog, which could bias results in favor of my proposals. In fact, the two top-voted individual proposals were my own papers on reflection and lightweight exceptions. But even if you remove those two, their topics are still in the top-voted categories of interest because there was strong voting in favor of “reflection” and “efficient exception/error handling” papers that were not written by me (e.g., the #4 and #5 papers were reflection and error handling papers that I didn’t write). Also, the post was Reddit’ed and it looks like most of the responses came via that. (Besides, happily/sadly, many of you who follow my blog freely disagree and argue with me so this isn’t just an echo chamber, and I also had a number of other papers that got fewer votes or none so you weren’t just upvoting my papers.)

Again, thank you very much to everyone who responded for your time and interest. I hope you find these results likewise interesting, and I’ve shared them with the committee as well.

I think this survey was a successful experiment. We’ll keep reading the data, especially the verbatims on how you would use the features you requested. But I think it’s fair that we can say already that, if nothing else, we now have some confirmation that the part of the community that responded supports the basic goals of P0592 so that paper is more than just the opinion of the author (who isn’t me)… that paper recommends that in the C++23 timeframe we focus our efforts on coroutines, executors, networking, reflection, and pattern matching. There’s a good correlation between that list and your “most-wanted papers’ topics” list above. That’s useful to learn, and we’ll look to learn more from your responses; thank you again.