Swift version of https://gist.github.com/booiiing/7941890

IntrinsicTableView.swift

import UIKit

class IntrinsicTableView: UITableView {

    override var contentSize:CGSize {
        didSet {
            self.invalidateIntrinsicContentSize()
        }
    }
    
    override func intrinsicContentSize() -> CGSize {
        self.layoutIfNeeded()
        return CGSize(width: UIViewNoIntrinsicMetric, height: self.contentSize.height)
    }
    
    override func endUpdates() {
        super.endUpdates()
        self.invalidateIntrinsicContentSize()
    }
    
    override func reloadData() {
        super.reloadData()
        self.invalidateIntrinsicContentSize()
    }
    
    override func reloadRowsAtIndexPaths(indexPaths: [NSIndexPath], withRowAnimation animation: UITableViewRowAnimation) {
        super.reloadRowsAtIndexPaths(indexPaths, withRowAnimation: animation)
        self.invalidateIntrinsicContentSize()
    }
    
    override func reloadSections(sections: NSIndexSet, withRowAnimation animation: UITableViewRowAnimation) {
        super.reloadSections(sections, withRowAnimation: animation)
        self.invalidateIntrinsicContentSize()
    }
    
    override func insertRowsAtIndexPaths(indexPaths: [NSIndexPath], withRowAnimation animation: UITableViewRowAnimation) {
        super.insertRowsAtIndexPaths(indexPaths, withRowAnimation: animation)
        self.invalidateIntrinsicContentSize()
    }
    
    override func insertSections(sections: NSIndexSet, withRowAnimation animation: UITableViewRowAnimation) {
        super.insertSections(sections, withRowAnimation: animation)
        self.invalidateIntrinsicContentSize()
    }
    
    override func deleteRowsAtIndexPaths(indexPaths: [NSIndexPath], withRowAnimation animation: UITableViewRowAnimation) {
        super.deleteRowsAtIndexPaths(indexPaths, withRowAnimation: animation)
        self.invalidateIntrinsicContentSize()
    }
    
    override func deleteSections(sections: NSIndexSet, withRowAnimation animation: UITableViewRowAnimation) {
        super.deleteSections(sections, withRowAnimation: animation)
        self.invalidateIntrinsicContentSize()
    }

}

Updated for swift4 https://gist.github.com/fabstu/2d8d78f67d24e71c9f59dbf8f5c3311d