feat: Introduce also, apply, applied extensions for Swift/iosApp

* Added iosAppShared folder for iosApp shared source codes.

Bug: tkuitocc#89
Change-Id: If5656816a1651437eeb091fe857ab3a568fc31bd

Author: winstonsung

iosApp/iosApp.xcodeproj/project.pbxproj

@@ -52,6 +52,11 @@
 			path = Configuration;
 			sourceTree = "<group>";
 		};
+		7555FF7A292A565900829871 /* iosAppShared */ = {
+			isa = PBXFileSystemSynchronizedRootGroup;
+			path = iosAppShared;
+			sourceTree = "<group>";
+		};
 		7555FF7D242A565900829871 /* iosApp */ = {
 			isa = PBXFileSystemSynchronizedRootGroup;
 			exceptions = (
@@ -105,6 +110,7 @@
 			isa = PBXGroup;
 			children = (
 				7555FF7929225F7C00F7AF9C /* Configuration */,
+				7555FF7A292A565900829871 /* iosAppShared */,
 				7555FF7D242A565900829871 /* iosApp */,
 				7555FFBE2E9CA65C0046E640 /* iosAppTests */,
 				7555FFC82E9CA65C0046E640 /* iosAppUITests */,
@@ -147,6 +153,7 @@
 			dependencies = (
 			);
 			fileSystemSynchronizedGroups = (
+				7555FF7A292A565900829871 /* iosAppShared */,
 				7555FF7D242A565900829871 /* iosApp */,
 			);
 			name = iosApp;

iosApp/iosAppShared/Extensions.swift

@@ -0,0 +1,37 @@
+public protocol Alsoable {}
+
+extension Alsoable {
+    @discardableResult
+    @inline(__always)
+    public func also(_ block: (Self) throws -> Void) rethrows -> Self {
+        try block(self)
+
+        return self
+    }
+}
+
+protocol ApplyableReference: AnyObject {}
+
+extension ApplyableReference {
+    @discardableResult
+    @inline(__always)
+    public func apply(_ block: (Self) throws -> Void) rethrows -> Self {
+        try block(self)
+
+        return self
+    }
+}
+
+public protocol ApplyableValue {}
+
+extension ApplyableValue {
+    @discardableResult
+    @inline(__always)
+    public func applied(_ block: (inout Self) throws -> Void) rethrows -> Self {
+        var copy: Self = self
+
+        try block(&copy)
+
+        return copy
+    }
+}