AlwaysEqual.swift

import Foundation

@propertyWrapper
public struct AlwaysEqual<T> {
    public var wrappedValue: T

    public init(wrappedValue: T) {
        self.wrappedValue = wrappedValue
    }
}

extension AlwaysEqual: Equatable {
    public static func == (lhs: AlwaysEqual<T>, rhs: AlwaysEqual<T>) -> Bool {
        return true
    }
}

struct Hoge: Equatable {
    var id: Int
    var name: String
}

let hogeA = Hoge(id: 1, name: "abcd")
let hogeB = Hoge(id: 1, name: "bcde")
let hogeC = Hoge(id: 2, name: "abcd")
print(hogeA == hogeB) // false
print(hogeA == hogeC) // false

struct Fuga: Equatable {
    var id: Int
    @AlwaysEqual var name: String
}

let fugaA = Fuga(id: 1, name: "abcd")
let fugaB = Fuga(id: 1, name: "bcde")
let fugaC = Fuga(id: 2, name: "abcd")
print(fugaA == fugaB) // true
print(fugaA == fugaC) // false