Is there a C strings library for C (not C++) that implements an abstraction over char * and wchar_t * strings?
char *
wchar_t *
The requirements are:
Something like ICU might be what you need. It's licensed under Open Source License, and doesn't exactly abstract char*/wchar_t* (see: http://icu-project.org/docs/papers/unicode_wchar_t.html), but it might be what you need.