31 Input/output library [input.output]

31.8 String-based streams [string.streams]

31.8.2 Class template basic_stringbuf [stringbuf]

31.8.2.5 Overridden virtual functions [stringbuf.virtuals]

Table 140: newoff values [tab:stringbuf.seekoff.newoff]
Condition
newoff Value
way == ios_base​::​beg
0
way == ios_base​::​cur
the next pointer minus the beginning pointer (xnext - xbeg).
way == ios_base​::​end
the high mark pointer minus the beginning pointer (high_mark - xbeg).