utf8 <-> utf16: codecvt poor performance

Question

I\'m looking onto some of my old (and exclusively win32 oriented) stuff and thinking about making it more modern/portable - i.e. reimplementing some widely reusable parts in C++

Answer 1

In my own testing, I found that the constructor call for wstring_convert has a massive overhead, at least on Windows. As other answers suggest, you'll probably struggle to beat the native Windows implementation, but try modifying your code to construct the converter outside of the loop. I expect you'll see an improvement of between 5x and 20x, particularly in a debug build.