Swift 4.1 (and above) Updated answer:

Starting from Swift 4.1, all you have to is to conform to the Equatable protocol without the need of implementing the == method. See: SE-0185 – Synthesizing Equatable and Hashable conformance.

Example:

struct MyStruct: Equatable {
    var id: Int
    var value: String
}

let obj1 = MyStruct(id: 101, value: "object")
let obj2 = MyStruct(id: 101, value: "object")

obj1 == obj2 // true

Keep in mind that the default behavior for the == is to compare all the type properties (based on the example: lhs.id == rhs.id && lhs.value == rhs.value). If you are aiming to achieve a custom behavior (comparing only one property for instance), you have to do it by yourself:

struct MyStruct: Equatable {
    var id: Int
    var value: String
}

extension MyStruct {
    static func ==(lhs: MyStruct, rhs: MyStruct) -> Bool {
        return lhs.id == rhs.id
    }
}

let obj1 = MyStruct(id: 101, value: "obj1")
let obj2 = MyStruct(id: 101, value: "obj2")

obj1 == obj2 // true

At this point, the equality would be based on the id value, regardless of what’s the value of value.