About matching the size of the View created in xib

Hello
I'm in trouble because I can't find it even if I look into it.
I would like to ask you two questions about creating a view of xib.
(Execution Xcode 8.2.1/Swift 3.0.2)

class CustomView:UIView {

    required init?(coder adecoder:NSCoder) {
        super.init(coder:aDecoder)
        let view = Bundle.main.loadNibNamed("Custom", owner:self, options:nil) ?.first as!UIView
        view.frame=bounds
        addSubview(view)
    }
}

By loading the View of the xib file in this way, adding it as a child of the view, and resizing it,
I was looking into what CustomView is in the article.Also, here

translatesAutoresizingMaskIntoConstraints=false

and Disable AutoResizeMask AutoResizeMask Automatic Constraint Add
Some articles set up AutoLayout.
Either way, the size is adjusted and the size is the same at runtime.

view.frame=bounds

If so, the layout such as the size of the View should not be determined at the time of init.
I prepared the iPhone 5 size (320x568) ViewController on the Storyboard and

CustomView limits View Controller's view to 0 up, down, left, and right.
I ran it on iPhone 6+ (414x736).
Of course, the results of the execution show CustomView full screen, but

view.frame=bounds

Even if you do this before the layout is finalized,
(
Before viewDidLayoutSubViews, which determine the size of the managed ViewController, etc. This init is called)
I don't know why the size fits perfectly.

print(view.frame.size)

and so on, but 320 x 568 is displayed here.
(Actual runtime size is 414x736)

Views with AutoLayout configured on IB in an article automatically

translatesAutoresizingMaskIntoConstraints=false

is configured and

 view.frame = CGRect (x:100, y:100, width:100, height:100)

As shown in , there is a possibility that you will not be able to make changes directly, and I feel that I have experienced such things myself.However, I can now adjust the position and size directly with frame regardless of translatesAutoresizingMaskIntoConstraints, but has it been changed with iOS 10 or Xcode 8.0?

I reviewed the UIView reference a little bit.Below are the functions and properties you are interested in.

• AutoresizesSubviews Do you want to use the automatic resize (what you told me)
• requiresConstraintBasedLayout Exactly if the constraint should work (get only)
• Set when you need to lay out sub-views more accurately than layoutSubViews constraints or auto-resize

If you want to specify directly, such as frames,
layoutSubViews() within a custom class. I understand that it's better to override...Summary of iOS layout

class CustomView:UIView {

    var subView —UIView!

    required init?(coder adecoder:NSCoder) {
        super.init(coder:aDecoder)
        subView= Bundle.main.loadNibNamed("Custom", owner:self, options:nil) ?.first as!UIView
        // Disable automatic resizing.
        autoresizesSubviews=false
        // View size is 320 x 568 for IB (6+ does not match 320 x 568) when running:
        // subView.frame=bounds
        addSubview(subView)
    }

    // Even if automatic resize is disabled, AutoLayout is set to CustomView on IB, so it is called when layout is confirmed and the size fits perfectly.
    // (Even if you set autoresizesSubviews=false for the View Controller, it fits perfectly.
    // We found that AutoLayout determines the layout.)
    override funclayoutSubviews() {
        subView.frame=bounds
    }
}