al_ustr_remove_chr - Allegro 5 API

       Remove  the code point beginning at byte offset pos.  Returns true on success.  If pos is out of range or
       pos is not the beginning of a valid code point, returns false leaving the string unmodified.

       Use al_ustr_offset(3alleg5) to find the byte offset for a code-points offset.

       al_ustr_remove_chr - Allegro 5 API

al_ustr_remove_range(3alleg5)

Allegro reference manual                                                             al_ustr_remove_chr(3alleg5)

              #include <allegro5/allegro.h>

              bool al_ustr_remove_chr(ALLEGRO_USTR *us, int pos)