reserveCapacity(_:)
Reserves enough space to store the specified number of key-value pairs.
Declaration
mutating func reserveCapacity(_ minimumCapacity: Int)Parameters
- minimumCapacity:
The requested number of key-value pairs to store.
Discussion
If you are adding a known number of key-value pairs to a dictionary, use this method to avoid multiple reallocations. This method ensures that the dictionary has unique, mutable, contiguous storage, with space allocated for at least the requested number of key-value pairs.
Calling the reserveCapacity(_:) method on a dictionary with bridged storage triggers a copy to contiguous storage even if the existing storage has room to store minimumCapacity key-value pairs.