any-equal.swift

// Dynamic cast without bridging
func dynamicCast<T>(_ type: T.Type, _ v: Any)->T? {
    guard let result = v as? T where v.dynamicType is T.Type else {
        return nil;
    }
    return result
}

// Return a 2uple if both objects are convertible to type T, otherwise nil
func matchCast<T>(_ type: T.Type, _ l: Any, _ r: Any)->(T, T)? {
    guard let l = dynamicCast(type, l) else {
        return nil;
    }
    
    guard let r = dynamicCast(type, r) else {
        return nil;
    }

    return (l, r)
}

// False for different dynamic types
// Reference equality for objects
// Operator == for known primitive types (Bool, String, Int*, UInt*, Float*, Double)
// Tuples, structs, sets, collections, and dictionaries get memberwise comparison
// Enums get a string comparison on their dump output
// False for everything else
func equal(_ l: Any, _ r: Any)->Bool {
    
    // Check if types are the same
    if (l.dynamicType != r.dynamicType) {
        return false
    }

// Include this if you import Foundation
//    if let m = matchCast(NSNumber.self, l, r) {
//        return m.0 == m.1
//    }
//    if let m = matchCast(NSString.self, l, r) {
//        return m.0 == m.1
//    }
    
    // Must come after primitive tests
    if let m = matchCast(AnyObject.self, l, r) {
        return m.0 === m.1 // Reference equality
    }
    
    if let m = matchCast(String.self, l, r) {
        return m.0 == m.1
    }
    
    if let m = matchCast(Bool.self, l, r) {
        return m.0 == m.1
    }
    
    if let m = matchCast(Int.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(Int8.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(Int16.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(Int32.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(Int64.self, l, r) {
        return m.0 == m.1
    }
    
    if let m = matchCast(UInt.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(UInt8.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(UInt16.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(UInt32.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(UInt64.self, l, r) {
        return m.0 == m.1
    }
    
    if let m = matchCast(Float.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(Float80.self, l, r) {
        return m.0 == m.1
    }
    if let m = matchCast(Double.self, l, r) {
        return m.0 == m.1
    }

    func equalCompound(_ l: Any, _ r : Any)->Bool {
        func isEnum(mirror: Mirror)->Bool {
            guard let ds = mirror.displayStyle else {
                return false;
            }
            return ds == .Enum
        }
        
        func equalDump(_ l: Any, _ r: Any)->Bool {
            var o1 = ""
            dump(l, &o1)
            
            var o2 = ""
            dump(r, &o2)
            
            return o1 == o2
        }
        
        func isWorkingDisplayStyle(ds: Mirror.DisplayStyle?)->Bool {
            guard let ds = ds else {
                return false;
            }
            switch (ds) {
            case .Class:
                return false // Don't expect to use because we use ref equality
            case .Enum:
                return false // Can't use because case doesn't show up in mirror (but associated data does)
            case .Collection:
                return true // Looks OK
            case .Dictionary:
                return true // Looks OK
            case .Optional:
                return true // Looks OK - works because the cases have different number of children
            case .Set:
                return true // Looks OK
            case .Tuple:
                return true // Looks OK
            case .Struct:
                return true // Looks OK
            }
        }
        let m1 = Mirror(reflecting: l)
        let m2 = Mirror(reflecting: r)
        
        if (isEnum(m1) && isEnum(m2)) {
            // We can't get the case from the Mirror object or dynamicType
            // so we resort to using dump and comparing the strings
            return equalDump(l, r)
        }
        
        guard (isWorkingDisplayStyle(m1.displayStyle)) &&
            (m1.displayStyle == m2.displayStyle) &&
            (m1.children.count == m2.children.count) else {
            return false;
        }
        
        for (p1, p2) in zip(m1.children, m2.children) {
            if (!equal(p1.1, p2.1)) {
                return false;
            }
        }
        return true
    }
    
    return equalCompound(l, r)
}

Code from http://www.callionica.com/developer/#any-equals