On Thursday, 2 March 2023 07:28:02 PST Steve Downey via SG16 wrote:
> That ICU apparently has poor performance in this area indicates a little
> that many users are OK with it. But it does also sound like there are use
> cases for eager algorithms that could provide better performance. Probably
> something like the ones that JeanHeyd was proposing for C?

I don't know the actual internals of those functions, but the wrapping API
with the needs of error code returning and the abstraction created by it do
make it slower than a pure, raw implementation would be. It's a price one pays
for having a consistent API for UTF-8 as well as Shift JIS or any other weird
codec that ICU may have available and you needed to decode content.