Change to use OptionSet type for ConsoleLogger.domains (#2349)

Instead of using Set<LogDomain>, changed to use OptionSet.

Swift/ConsoleLogger.swift

@@ -20,6 +20,33 @@
 import Foundation
 
 /// Console logger for writing log messages to the system console.
+
+/// Log domain options that can be enabled in the console logger.
+public struct LogDomains: OptionSet {
+    /// Raw value.
+    public let rawValue: Int
+
+    /// Constructor with the raw value.
+    public init(rawValue: Int) {
+        self.rawValue = rawValue
+    }
+
+    /// All domains.
+    public static let all = LogDomains(rawValue: Int(LogDomain.all.rawValue))
+
+    /// Database domain.
+    public static let database = LogDomains(rawValue: Int(LogDomain.database.rawValue))
+
+    /// Database domain.
+    public static let query = LogDomains(rawValue: Int(LogDomain.query.rawValue))
+
+    /// Replicator domain.
+    public static let replicator = LogDomains(rawValue: Int(LogDomain.replicator.rawValue))
+
+    /// Network domain.
+    public static let network = LogDomains(rawValue: Int(LogDomain.network.rawValue))
+}
+
 public class ConsoleLogger {
 
     /// The minimum log level of the log messages to be logged. The default log level for
@@ -32,13 +59,9 @@ public class ConsoleLogger {
 
     /// The set of log domains of the log messages to be logged. By default, the log
     /// messages of all domains will be logged.
-    public var domains: Set<LogDomain> = [.all] {
+    public var domains: LogDomains = .all {
         didSet {
-            var domain: UInt8 = 0
-            for d in domains {
-                domain = domain | d.rawValue
-            }
-            CBLDatabase.log().console.domains = CBLLogDomain(rawValue: UInt(domain))
+            CBLDatabase.log().console.domains = CBLLogDomain(rawValue: UInt(domains.rawValue))
         }
     }
 

Swift/Tests/LogTest.swift

@@ -337,7 +337,7 @@ class LogTest: CBLTestCase {
         let customLogger = LogTestLogger()
         customLogger.level = .verbose
         Database.log.custom = customLogger
-        Database.log.console.domains = [LogDomain.all]
+        Database.log.console.domains = .all
         Database.log.console.level = .verbose
         let hebrew = "מזג האוויר נחמד היום" // The weather is nice today.
         let doc = MutableDocument()