Add bounds checking on abc::text::codepoint_iterator, share code with abc::str_base::operator[]()
Improve code documentation
Consolidate and simplify abc::str_base::translate_index*()
Improve code documentation
Throw abc::pointer_iterator_error when appropriate in abc::str_base::_advance_char_ptr()
Display all information available to abc::pointer_iterator_error::_print_extended_info()
Add more test cases for code that results in calls to abc::str_base::_advance_char_ptr()
Rename arguments/variables for semantics
Remove explicit istr() calls that can be implicit
Use static_cast<>() instead of constructor call-style casts