Member typevalue_typeis the type of the elements in the container, defined invectoras an alias of its first template parameter (T). first, last Input iteratorsto the initial and final positions in a range. The range used is[first,last), which includes all the elements betweenfirstandlast, ...
First, we’ve initialized the vector with 3 elements. This causes the vector to allocate storage for 3 elements (capacity is 3), and all 3 elements are considered to be in active use (length = 3). We then callresize(5), meaning we now want a vector with a length of 5. Since the...
The most efficient way to add elements to a vector is by using push_back() or emplace_back() to append elements to the end of the vector. For better performance, if you know the number of elements in advance, use reserve() to allocate sufficient memory upfront and avoid repea...
When pushing triggers a reallocation, std::vector will typically allocate some extra capacity to allow additional elements to be added without triggering another reallocation the next time an element is added. How much extra capacity is allocated is left up to the compiler’s implementation of std...
allocate space for its 1000 objects (because the whole point is to be able to do this concurrently) and thread B starts constructing its objects. Thread A finishes first (it only has 50 elements to construct), it updatessizeto reflect the additional 50 objects. Thread B finishes and it ...