Google low level C++ APIs

This is one of those questions that keeps coming up... "What core/low-level libraries has Google released as open source?"  As someone who works inside of Google, I already know a lot of them and when I work on external code (e.g. GDAL) I have to work extra hard because the tools I normally reach for are not there.  One of those is the C++ strings substitute.h.  I just went looking and found it:

https://github.com/google/lmctfy/blob/master/strings/substitute.h
https://github.com/google/protobuf/blob/master/src/google/protobuf/stubs/substitute.h
https://github.com/google/supersonic/blob/master/supersonic/utils/strings/substitute.h
https://github.com/google/sensei/blob/master/sensei/strings/substitute.h

The question then becomes, where do I find the latest open sourced version and how do I use it in a library that will be used by many other people such as GDAL or libais?  I probably have to move it into a gdal or osgeo namespace or it's going to clash at link time.  If it's just an end tool, there there is less worry.