add iOS

iOS-SwiftUI-Code/GRDB.swift-6.29.3/GRDB/Utils/Refinable.swift

@@ -0,0 +1,36 @@
+/// A marker protocol for refinable types.
+///
+/// For example:
+///
+///     struct Player {
+///         var name: String
+///         var score: Int
+///     }
+///
+///     extension Player: Refinable { }
+///
+///     let player = Player(name: "Arthur", score: 1000)
+///
+///     // Player(name: "Arthur", score: 100)
+///     let newPlayer = player.with {
+///         $0.score = 100
+///     }
+protocol Refinable { }
+
+extension Refinable {
+    /// Returns self modified with the *update* function.
+    ///
+    /// For example:
+    ///
+    ///     let player = Player(name: "Arthur", score: 1000)
+    ///     let newPlayer = player.with {
+    ///         $0.score = 100
+    ///     }
+    ///     newPlayer.name  // "Arthur"
+    ///     newPlayer.score // 100
+    func with(_ update: (inout Self) throws -> Void) rethrows -> Self {
+        var result = self
+        try update(&result)
+        return result
+    }
+}