First version.

Author: BB9z

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright © 2020-2021 BB9z
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Package.swift

@@ -4,12 +4,12 @@
 import PackageDescription
 
 let package = Package(
-    name: "AssociatedObject",
+    name: "B9AssociatedObject",
     products: [
         // Products define the executables and libraries a package produces, and make them visible to other packages.
         .library(
-            name: "AssociatedObject",
-            targets: ["AssociatedObject"]),
+            name: "B9AssociatedObject",
+            targets: ["B9AssociatedObject"]),
     ],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
@@ -19,10 +19,10 @@ let package = Package(
         // Targets are the basic building blocks of a package. A target can define a module or a test suite.
         // Targets can depend on other targets in this package, and on products in packages this package depends on.
         .target(
-            name: "AssociatedObject",
+            name: "B9AssociatedObject",
             dependencies: []),
         .testTarget(
-            name: "AssociatedObjectTests",
-            dependencies: ["AssociatedObject"]),
+            name: "MainTests",
+            dependencies: ["B9AssociatedObject"]),
     ]
 )

README.md

@@ -1,3 +1,37 @@
-# AssociatedObject
+# B9AssociatedObject
 
-A description of this package.
+[![Swift Version](https://img.shields.io/badge/Swift-5.3+-F05138.svg?style=flat-square)](https://swift.org)
+[![Swift Package Manager](https://img.shields.io/badge/spm-compatible-F05138.svg?style=flat-square)](https://swift.org/package-manager)
+[![Build Status](https://img.shields.io/github/workflow/status/b9swift/Action/Swift?style=flat-square&colorA=555555&colorB=F05138)](https://github.com/b9swift/AssociatedObject/actions)
+[![gitee 镜像](https://img.shields.io/badge/%E9%95%9C%E5%83%8F-gitee-C61E22.svg?style=flat-square)](https://gitee.com/b9swift/AssociatedObject)
+[![GitHub Source](https://img.shields.io/badge/Source-GitHub-24292F.svg?style=flat-square)](https://github.com/b9swift/AssociatedObject)
+
+Objective-C associated object 的 Swift 封装。
+
+Objective-C associated value wrapper.
+
+## 集成
+
+使用 Swift Package Manager 或手工导入。
+
+You can also use [GitHub source](https://github.com/b9swift/AssociatedObject).
+
+## Installation
+
+Using Swift Package Manager or import manually.
+
+你也可以使用 [gitee 镜像](https://gitee.com/b9swift/AssociatedObject)。
+
+## 使用
+
+## Usage
+
+```swift
+private let fooAssociation = AssociatedObject<String>()
+extension SomeObject {
+    var foo: String? {
+        get { fooAssociation[self] }
+        set { fooAssociation[self] = newValue }
+    }
+}
+```

Sources/AssociatedObject/AssociatedObject.swift

@@ -0,0 +1,43 @@
+/*
+ AssociatedObject.swift
+
+ Copyright © 2020-2021 RFUI.
+ https://github.com/b9swift/AssociatedObject
+
+ The MIT License
+ https://opensource.org/licenses/MIT
+ */
+
+import Foundation
+
+/**
+ Objective-C associated value wrapper.
+
+ Usage
+
+ ```
+ private let fooAssociation = AssociatedObject<String>()
+ extension SomeObject {
+     var foo: String? {
+         get { fooAssociation[self] }
+         set { fooAssociation[self] = newValue }
+     }
+ }
+ ```
+ */
+public final class AssociatedObject<T> {
+    private let policy: objc_AssociationPolicy
+
+    /// Creates an associated value wrapper.
+    /// - Parameter policy: The policy for the association.
+    public init(policy: objc_AssociationPolicy = .OBJC_ASSOCIATION_RETAIN_NONATOMIC) {
+        self.policy = policy
+    }
+
+    /// Accesses the associated value.
+    /// - Parameter index: The source object for the association.
+    public subscript(index: AnyObject) -> T? {
+        get { objc_getAssociatedObject(index, Unmanaged.passUnretained(self).toOpaque()) as? T }
+        set { objc_setAssociatedObject(index, Unmanaged.passUnretained(self).toOpaque(), newValue, policy) }
+    }
+}

Sources/B9AssociatedObject/B9AssociatedObject.swift

@@ -0,0 +1,6 @@
+import XCTest
+@testable import B9AssociatedObject
+
+final class AssociatedObjectTests: XCTestCase {
+
+}