Dictionary and sequence now have the capacity to explicitly, unambiguously reserve capacity.
Suppose you have a sequence of friends with an initial capacity of 4:
friends.capacity // 4
You can now reserve the capacity by doing this:
friends.reserveCapacity(20)
This reserves a minimum of 20 segments of capacity:
friends.capacity // 20
Reallocating memory to objects can be an expensive task, and if you have an idea about how much space it will require to store an object, then using reserveCapacity(_:) can be an easy and simple way to increase performance.
Swift 4 brings in a number of modifications to the Dictionary, 12 to be exact as per the official Apple developers guide, and a number of additions that we will discuss ...
