Vadim-Yelagin

import Foundation

func invocation<C: AnyObject, In, Out>
	(target target: C, method: C -> In -> Out)
	-> In -> Out?
{
	return {
		[weak target] input in
		if let target = target {
			return method(target)(input)

Vadim-Yelagin

extension CollectionType where Index: RandomAccessIndexType {

	/// Finds such index N that predicate is true for all elements up to
	/// but not including the index N, and is false for all elements
	/// starting with index N.
	/// Behavior is undefined if there is no such N.
	func binarySearch(predicate: Generator.Element -> Bool) -> Index {
		var low = startIndex
		var high = endIndex
		while low != high {

Vadim-Yelagin

func animatingContext(duration: TimeInterval) -> ((@escaping (Void) -> Void) -> Void) {
	return { UIView.animate(withDuration: duration, animations: $0) }
}

public extension SignalProtocol {
	public func observe(context: @escaping (@escaping (Void) -> Void) -> Void) -> Signal<Value, Error> {
		return Signal { observer in
			return self.observe { event in
				switch event {
				case .value: