vector pointer locations guaranteed?

Question

Suppose I have a vector of ints,

std::vector numbers;

that is populated with a bunch of values, then I say do this (where an ent

Answer 1

No - the vector can be reallocated when it grows. Usually once the vector doubles in size.

From the C++11 standard

1 Remarks: Causes reallocation if the new size is greater than the old capacity. If no
reallocation happens, all the iterators and references before the insertion point
remain valid. If an exception is thrown other than by the copy constructor, move 
constructor, assignment operator, or move assignment operator of T or by any 
InputIterator operation there are no effects. If an exception is thrown by the move 
constructor of a non-CopyInsertable T, the effects are unspecified.