对象池

import PackageDescription

let package = Package(
    name: "YourProject",
    products: [
      .executable(name: "YourProject", targets: ["YourProject"])
    ],
    dependencies: [
        .package(url: "https://github.com/reswifq/pool.git", .upToNextMajor(from: "1.3.0"))
    ],
    targets: [
      .target(name: "YourProject", dependencies: ["Pool"])
    ]
)

let pool = Pool(maxElementCount: 10) {
	return "I am a pool element"
}

let element = try pool.draw()

print(element) // "I am a pool element"

pool.release(element)

pool.release(element) {
	print("element has been released and it's ready to be drawn again")
}