: A directive that informs a
of a planned change in size, so that it can manage the storage allocation accordingly.
is greater or equal to the argument of
if reallocation happens; and equal to the previous value of
Reallocation happens at this point if and only if the current capacity is less than the
If an exception is thrown
other than by the move constructor of a non-Cpp17CopyInsertable
there are no effects.