Updates build settings to use Swift 4.2.

Removes references to checking for Swift version 4.0. Removes unused import.

Author: laurentaylormarshall

Quicksort/Quicksort.playground/Contents.swift

@@ -1,10 +1,5 @@
 //: Playground - noun: a place where people can play
 
-// last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
-#endif
-
 import Foundation
 
 // *** Simple but inefficient version of quicksort ***

Quicksort/Tests/QuicksortTests.swift

@@ -1,13 +1,6 @@
 import XCTest
 
 class QuicksortTests: XCTestCase {
- func testSwift4() {
- // last checked with Xcode 9.0b4
- #if swift(>=4.0)
- print("Hello, Swift 4!")
- #endif
- }
- 
  func testQuicksort() {
  checkSortAlgorithm(quicksort)
  }

Quicksort/Tests/SortingTestHelpers.swift

@@ -1,4 +1,3 @@
-import Foundation
 import XCTest
 
 func randomArray(_ size: Int) -> [Int] {

Quicksort/Tests/Tests-Quicksort.xcodeproj/project.pbxproj

@@ -86,7 +86,7 @@
 isa = PBXProject;
 attributes = {
 LastSwiftUpdateCheck = 0720;
-LastUpgradeCheck = 0900;
+LastUpgradeCheck = 1000;
 ORGANIZATIONNAME = "Swift Algorithm Club";
 TargetAttributes = {
 7B2BBC7F1C779D720067B71D = {
@@ -149,12 +149,14 @@
 CLANG_WARN_BOOL_CONVERSION = YES;
 CLANG_WARN_COMMA = YES;
 CLANG_WARN_CONSTANT_CONVERSION = YES;
+CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
 CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 CLANG_WARN_EMPTY_BODY = YES;
 CLANG_WARN_ENUM_CONVERSION = YES;
 CLANG_WARN_INFINITE_RECURSION = YES;
 CLANG_WARN_INT_CONVERSION = YES;
 CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
 CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
 CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
@@ -187,7 +189,7 @@
 SDKROOT = macosx;
 SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 SWIFT_SWIFT3_OBJC_INFERENCE = Off;
-SWIFT_VERSION = 4.0;
+SWIFT_VERSION = 4.2;
 };
 name = Debug;
 };
@@ -203,12 +205,14 @@
 CLANG_WARN_BOOL_CONVERSION = YES;
 CLANG_WARN_COMMA = YES;
 CLANG_WARN_CONSTANT_CONVERSION = YES;
+CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
 CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 CLANG_WARN_EMPTY_BODY = YES;
 CLANG_WARN_ENUM_CONVERSION = YES;
 CLANG_WARN_INFINITE_RECURSION = YES;
 CLANG_WARN_INT_CONVERSION = YES;
 CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
 CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
 CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
@@ -234,7 +238,7 @@
 SDKROOT = macosx;
 SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 SWIFT_SWIFT3_OBJC_INFERENCE = Off;
-SWIFT_VERSION = 4.0;
+SWIFT_VERSION = 4.2;
 };
 name = Release;
 };

Quicksort/Tests/Tests-Quicksort.xcodeproj/xcshareddata/xcschemes/Tests-Quicksort.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
- LastUpgradeVersion = "0900"
+ LastUpgradeVersion = "1000"
  version = "1.3">
  <BuildAction
  parallelizeBuildables = "YES"
@@ -10,7 +10,6 @@
  buildConfiguration = "Debug"
  selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
  selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
- language = ""
  shouldUseLaunchSchemeArgsEnv = "YES">
  <Testables>
  <TestableReference
@@ -31,7 +30,6 @@
  buildConfiguration = "Debug"
  selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
  selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
- language = ""
  launchStyle = "0"
  useCustomWorkingDirectory = "NO"
  ignoresPersistentStateOnLaunch = "NO"