RxSwift-article-9.swift

RxSwift-article-9.swift

public mutating func insert(element: T) -> BagKey {
    _nextKey = _nextKey &+ 1

#if DEBUG
    _nextKey = _nextKey % 20
#endif
    
    if _nextKey == 0 {
        _uniqueIdentity = Identity()
    }

    let key = BagKey(uniqueIdentity: _uniqueIdentity, key: _nextKey)

    if _key0 == nil {
        _key0 = key
        _value0 = element
        return key
    }

    _onlyFastPath = false

    if _key1 == nil {
        _key1 = key
        _value1 = element
        return key
    }

    if _dictionary != nil {
        _dictionary![key] = element
        return key
    }

    if _pairs.count < arrayDictionaryMaxSize {
        _pairs.append(key: key, value: element)
        return key
    }

    if _dictionary == nil {
        _dictionary = [:]
    }

    _dictionary![key] = element
    
    return key
}