std::memset only works for sequential and contiguous memory. std::fill works on pretty much anything that has std::begin() and std::end().

As the conclusion of the article says I would use the idiomatic way first, then and only if I have performance issues, actually force it to memset.

The only bad thing here is that, gcc only do the reasonable optimization on '-O3'.

The issue with browser extensions, is that you are not far away from the common hurdles of developing, using and releasing a "real" desktop/mobile application. Having nothing to install and landing on a page that just works, is a big plus for you users.