What would be a QString replacement?

For many reasons (low performance, high resource consumption, large shared library size, large executable sizes, and our low end platform) my team consider moving out of Qt. As a part of this we search for a replacement to QString class, which would allow a) unicode b) regular expressions c) general operations such as getting substrings, substring search, length (quantity of characters n开发者_高级运维ot bytes), concatenation, etc. Also it should store strings internally in UTF-8 encoding, to save memory (Qt uses UTF-16 or alike). Also it would be great if it would use "Implicit Sharing" technique, as QString does. Is there any LGPL (or similar) ready-to-use class of the sort in the universe?...

I'd just use std::string with Boost String Algorithms and UTF-8 CPP

You may want to have a look at my library plis, which does everything you asked for above except implicit sharing. See:

http://libplis.sourceforge.net/docs/index.html