About 14 months ago I posted the same thing.  There was significant work that needed to be done to Boost.Text (the proposed library), and I was a bit burned out.

Now I've managed to make the necessary changes, and I feel the library is ready for review, if there is interest.

This library, in part, is something I want to standardize.

It started as a better string library for namespace "std2", with minimal Unicode support.  Though "std2" will almost certainly never happen now, those string types are still in there, and the library has grown to also include all the Unicode features most users will ever need.

Github: https://github.com/tzlaine/text
Online docs: https://tzlaine.github.io/text

If you care about portable Unicode support, or even addressing the embarrassment of being the only major production language with next to no Unicode support, please have a look and provide feedback.

I gave a talk about this at C++Now in May 2018, and now it's a bit out of date, as the library was not then finished.  It's three hours, so, y'know, maybe skip it.  For completeness' sake:

https://www.youtube.com/watch?v=944GjKxwMBo&index=7&list=PL_AKIMJc4roVSbTTfHReQTl1dc9ms0lWH
https://www.youtube.com/watch?v=GJ2xMAqCZL8&list=PL_AKIMJc4roVSbTTfHReQTl1dc9ms0lWH&index=8

Zach