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:
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:
At this point, the equality would be based on the id
value, regardless of what's the value of value
.
https://stackoverflow.com/questions/37541512/swift-struct-doesnt-conform-to-protocol-equatable
猜测:下面两者的签名形式应该是相同的
/// Represents a response to a `MoyaProvider.request`.
public final class Response: CustomDebugStringConvertible, Equatable {
public static func == (lhs: Response, rhs: Response) -> Bool {
return lhs.statusCode == rhs.statusCode
&& lhs.data == rhs.data
&& lhs.response == rhs.response
}
}
public func ==(lhs: ConstraintItem, rhs: ConstraintItem) -> Bool {
// pointer equality
guard lhs !== rhs else {
return true
}
// must both have valid targets and identical attributes
guard let target1 = lhs.target,
let target2 = rhs.target,
target1 === target2 && lhs.attributes == rhs.attributes else {
return false
}
return true
}