// Add this to the dependencies of your package.
.package(url: "https://github.com/kaiengelhardt/consti", from: "1.0.0"),

// Then add this to the dependencies of the targets you want to use Consti in.
.product(name: "Consti", package: "Consti"),

view.addSubview(contentView)
contentView.translatesAutoresizingMaskIntoConstraints = false

// Instead of this:
NSLayoutConstraint.activate([
	contentView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
	contentView.topAnchor.constraint(equalTo: view.topAnchor),
	contentView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
	contentView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
])

// You can now write this:
NSLayoutConstraint.activate(contentView.constraintsMatchingEdgesOfSuperview())

view.addSubview(contentView)
contentView.translatesAutoresizingMaskIntoConstraints = false

// Instead of this:
NSLayoutConstraint.activate([
	contentView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
	contentView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
	contentView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
	contentView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
])

// You can now write this:
NSLayoutConstraint.activate(contentView.constraintsMatchingEdges(of: view.safeAreaLayoutGuide))

view.addSubview(contentView)
contentView.translatesAutoresizingMaskIntoConstraints = false

// Constrain contentView the have at most the area of the view, minus 40 points on each side.
NSLayoutConstraint.activate(
	contentView.constraintsMatchingEdges(
		of: view,
		insetBy: NSDirectionalEdgeInsets(top: 40, leading: 40, bottom: 40, trailing: 40),
		relation: .lessThanOrEqual
	)
)

// Constrain contentView to have the double the width and 32 points more in height than someOtherView.
NSLayoutConstraint.activate(
	contentView.constraintsMatchingSize(
		of: someOtherView,
		resizedBy: CGSize(width: 0, height: 32),
		multipliedBy: CGSize(width: 2, height: 1)
	)
)

NSLayoutConstraint.activate([
	contentView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
	// Set priority without needing to assign to a local variable.
	contentView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor)
		.with(priority: .defaultLow),
	contentView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
	contentView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
])

// Set priority on an entire array of constraints.
NSLayoutConstraint.activate(contentView.constraintsMatchingEdges(of: view.safeAreaLayoutGuide)
	.with(priority: .defaultHigh))

// Set up aspect ratio.
imageView.aspectRatioConstraint().isActive = true // 1:1 aspect ratio
imageView.aspectRatioConstraint(ratio: 16 / 9).isActive = true // 16:9 aspect ratio

// Center a view.
NSLayoutConstraint.activate(imageView.constraintsMatchingCenterOfSuperview())

// Match the size of one view to another.
NSLayoutConstraint.activate(imageView.constraintsMatchingSize(of: someOtherView))

// Match the size of an array of views.
let buttons = [/* ... */]
NSLayoutConstraint.activate(buttons.constraintsMatchingSize())

@ActiveConstraint() private var buttonConstraints: [NSLayoutConstraint]

override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
	super.traitCollectionDidChange(previousTraitCollection)
	let isiPhonePortrait = traitCollection.verticalSizeClass == .regular
		&& traitCollection.horizontalSizeClass == .compact
	if isiPhonePortrait {
		buttonConstraints = ... // Constraints for portrait layout.
	} else {
		buttonConstraints = ... // Constraints for landscape layout.
	}
}