Mutation with Struct & Class

mutation.swift

struct AStruct {
    let letRefValue = "foo"
    var varRefValue = "bar"
    let letDataValue = 0
    var varDataValue = 0

    func changeLetRefValue() {
        letRefValue = "hello" //< Cannot assign to property: 'letRefValue' is a 'let' constant
    }

    func changeVarRefValue() {
        varRefValue = "hello" //< Cannot assign to property: 'self' is immutable
    }

    func changeLetDataValue() {
        letDataValue = 1 //< Cannot assign to property: 'letDataValue' is a 'let' constant
    }

    func changeVarDataValue() {
        varDataValue = 1 //< Cannot assign to property: 'self' is immutable
    }
}

class AClass {
    let letRefValue = "foo"
    var varRefValue = "bar"
    let letDataValue = 0
    var varDataValue = 0

    func changeLetRefValue() {
        letRefValue = "hello" //< Cannot assign to property: 'letRefValue' is a 'let' constant
    }

    func changeVarRefValue() {
        varRefValue = "hello"
    }

    func changeLetDataValue() {
        letDataValue = 1 //< Cannot assign to property: 'letDataValue' is a 'let' constant
    }

    func changeVarDataValue() {
        varDataValue = 1
    }
}

let letAStruct = AStruct()
letAStruct.letRefValue = "hello" //< Cannot assign to property: 'letRefValue' is a 'let' constant
letAStruct.varRefValue = "hello" //< Cannot assign to property: 'letAStruct' is a 'let' constant
letAStruct.letDataValue = 1 //< Cannot assign to property: 'letDataValue' is a 'let' constant
letAStruct.varDataValue = 1 //< Cannot assign to property: 'letAStruct' is a 'let' constant

var varAStruct = AStruct()
varAStruct.letRefValue = "hello" //< Cannot assign to property: 'letRefValue' is a 'let' constant
varAStruct.varRefValue = "hello"
varAStruct.letDataValue = 1 //< Cannot assign to property: 'letDataValue' is a 'let' constant
varAStruct.varDataValue = 1

let letAClass = AClass()
letAClass.letRefValue = "hello" //< Cannot assign to property: 'letRefValue' is a 'let' constant
letAClass.varRefValue = "hello"
letAClass.letDataValue = 1 //< Cannot assign to property: 'letDataValue' is a 'let' constant
letAClass.varDataValue = 1

var varAClass = AClass()
varAClass.letRefValue = "hello" //< Cannot assign to property: 'letRefValue' is a 'let' constant
varAClass.varRefValue = "hello"
varAClass.letDataValue = 1 //< Cannot assign to property: 'letDataValue' is a 'let' constant
varAClass.varDataValue = 1