Reserves enough space to store the specified number of key-value pairs.
- Xcode 9.0+
- Swift Standard Library
The requested number of key-value pairs to store.
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.
reserve method on a dictionary with bridged storage triggers a copy to contiguous storage even if the existing storage has room to store
minimum key-value pairs.