string concat benchmarks

StringsTest.swift

import XCTest

let count = 50000

class StringsTestTests: XCTestCase {

    // MARK: Copying

    func testInterpolation() {
        var foo = ""
        measure {
            foo = "foo"
            for _ in 0 ..< count {
                foo = "\(foo)bar"
            }
        }
        print(foo)
    }

    func testPlusOperator() {
        var foo = ""
        measure {
            foo = "foo"
            for _ in 0 ..< count {
                foo = foo + "bar"
            }
        }
        print(foo)
    }

    func testAppending() {
        var foo = ""
        measure {
            foo = "foo"
            for _ in 0 ..< count {
                foo = foo.appending("bar")
            }
        }
        print(foo)
    }

    // MARK: Mutating

    func testPlusEquals() {
        var foo = ""
        measure {
            foo = "foo"
            for _ in 0 ..< count {
                foo += "bar"
            }
        }
        print(foo)
    }

    func testAppend() {
        var foo = ""
        measure {
            foo = "foo"
            for _ in 0 ..< count {
                foo.append("bar")
            }
        }
        print(foo)
    }
}