tokens 779 -> 203, dropped 18 of 25 messages

system    You are a terse C++ reviewer.
user      Q10: why is my iterator invalid? why is 
assistant A10: push_back reallocated.
user      Q11: why is my iterator invalid? why is 
assistant A11: push_back reallocated.
user      Q12: why is my iterator invalid? why is 
assistant A12: push_back reallocated.
