Swift 3.0 排序 - 传递给不带参数的调用的参数

Question

我目前正在尝试将一些 Swift 2 代码移植到 Swift 3.0。

这是让我发疯的一行代码。

    public private(set) var searchHistory: [SearchHistoryEntry] = [SearchHistoryEntry]() // Struct that is cComparable 
....
...
    searchHistory.sortInPlace({ $0.lastUsage.isAfter($1.lastUsage) })

这是我的 Swift 3.0 版本

searchHistory.sort(by:{ $0.lastUsage.isAfter($1.lastUsage) })

lastUsage 的类型是日期

编译器提示以下错误信息

传递给不带参数的调用的参数

任何想法我做错了什么？ 我真的不明白编译器想告诉什么。 排序需要一个 block ，我通过了它，一切都应该没问题。

更新

我发现了错误。 Swift 将所有 NSDate 属性转换为 Date，我们在 NSDate 上得到了一个名为 isAfter 的扩展。所以编译器再也找不到 isAfter 了。编译器错误消息完全具有误导性。

Answer 1

我会使用 sorted(by: ) 即

searchHistory.sorted(by: {$0.lastUsage > $1.lastUsage})

完整的工作示例:

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM-dd-yyyy"

struct ExerciseEquipment
{
    let name: String
    let lastUsage: Date
}

let myExerciseEquipment =
[
    ExerciseEquipment(name: "Golf Clubs", lastUsage: dateFormatter.date(from: "03-16-2015")!),
    ExerciseEquipment(name: "Tennis Racket", lastUsage: dateFormatter.date(from: "06-30-2003")!),
    ExerciseEquipment(name: "Skis", lastUsage: dateFormatter.date(from: "02-08-2017")!),
    ExerciseEquipment(name: "Hockey Stick", lastUsage: dateFormatter.date(from: "09-21-2010")!),
    ExerciseEquipment(name: "Mountain Bike", lastUsage: dateFormatter.date(from: "10-30-2016")!)
]

print(myExerciseEquipment.sorted(by: {$0.lastUsage > $1.lastUsage}))

...结果

[ExerciseEquipment(name: "Skis", lastUsage: 2017-02-08 05:00:00 +0000), ExerciseEquipment(name: "Mountain Bike", lastUsage: 2016-10-30 04:00:00 +0000), ExerciseEquipment(name: "Golf Clubs", lastUsage: 2015-03-16 04:00:00 +0000), ExerciseEquipment(name: "Hockey Stick", lastUsage: 2010-09-21 04:00:00 +0000), ExerciseEquipment(name: "Tennis Racket", lastUsage: 2003-06-30 04:00:00 +0000)]