Grow arrays by a factor less than 2?

[johnmyleswhite]

I recently discovered this document in one of FB’s open source libraries for C++: https://github.com/facebook/folly/blob/master/folly/docs/FBVector.md

It makes an interesting argument for growing arrays by a factor smaller than 2 when resizing them so that you can reuse memory more easily. Not sure how much you also need to use a custom malloc routine to get the benefits being claimed, but I thought I'd raise the idea in case we can get any performance enhancements from these ideas.

[JeffBezanson]

This seems like a good idea.

[quinnj]

Another data point
http://blog.mozilla.org/nnethercote/2014/11/04/please-grow-your-buffers-exponentially/

[vchuravy]

ArrayList in Java uses 1.5 as growth factor and [1] gives a bit more background on why this might be considered more optimal.

[1] http://crntaylor.wordpress.com/2011/07/15/optimal-memory-reallocation-and-the-golden-ratio/