Optional Comparable and Equatable helpers.

1-Example.swift

let value1: Int? = 1
let value2: Int? = 2
let nilValue: Int? = nil

value1 <? value2    // true
value1 <? nilValue  // false

value2 != nilValue  // true
value2 !=? nilValue // false

2-NilCoalescingComparisons.swift

infix operator >?: NilCoalescingPrecedence
infix operator >=?: NilCoalescingPrecedence
infix operator <?: NilCoalescingPrecedence
infix operator <=?: NilCoalescingPrecedence
infix operator !=?: NilCoalescingPrecedence

public extension Optional where Wrapped: Comparable {
  /// Unwraps both sides, returning `false` if either is `nil`, then performs the comparison check.
  static func >? (lhs: Wrapped?, rhs: Wrapped?) -> Bool {
    guard let lhs = lhs, let rhs = rhs else {
      return false
    }
    
    return lhs > rhs
  }
  
  /// Unwraps both sides, returning `false` if either is `nil`, then performs the comparison check.
  static func >=? (lhs: Wrapped?, rhs: Wrapped?) -> Bool {
    guard let lhs = lhs, let rhs = rhs else {
      return false
    }
    
    return lhs >= rhs
  }
  
  /// Unwraps both sides, returning `false` if either is `nil`, then performs the comparison check.
  static func <? (lhs: Wrapped?, rhs: Wrapped?) -> Bool {
    guard let lhs = lhs, let rhs = rhs else {
      return false
    }
    
    return lhs < rhs
  }
  
  /// Unwraps both sides, returning `false` if either is `nil`, then performs the comparison check.
  static func <=? (lhs: Wrapped?, rhs: Wrapped?) -> Bool {
    guard let lhs = lhs, let rhs = rhs else {
      return false
    }
    
    return lhs <= rhs
  }
}

public extension Optional where Wrapped: Equatable {
  /// Unwraps both sides, returning `false` if either is `nil`, then performs the equation check.
  static func !=? (lhs: Wrapped?, rhs: Wrapped?) -> Bool {
    guard let lhs = lhs, let rhs = rhs else {
      return false
    }
    
    return lhs != rhs
  }
}