[jcelerier]

> This avoids default-constructing all of the values inside of it, only to overwrite them with the new values you're copying in.

I think that I saw a few benchmarks once showing that for primitive types such as int & such, it was actually more efficient to resize() ; only past 32 or 64 bytes structs did reserving' become more interesting. In any case, when nitpicking on this it's even better to use boost::vector which allows to do an uninitialized resize : http://www.boost.org/doc/libs/1_66_0/doc/html/container/exte....

[bstamour]

That's interesting, and a bit counter-intuitive IMO. But I guess that's why we measure things. The reserve operation is essentially just a single reallocation, whereas the resize is a reallocation plus a bunch of zeroing out. Strange.