Mark Property and MutableProperty as property wrappers.

Sources/Property.swift

@@ -470,6 +470,7 @@ extension PropertyProtocol where Value == Bool {
 /// deinitializing.
 ///
 /// Note that composed properties do not retain any of its sources.
+@propertyWrapper
 public final class Property<Value>: PropertyProtocol {
 	private let _value: () -> Value
 
@@ -478,6 +479,16 @@ public final class Property<Value>: PropertyProtocol {
 		return _value()
 	}
 
+	@inlinable
+	public var wrappedValue: Value {
+		return value
+	}
+
+	@inlinable
+	public var projectedValue: Property<Value> {
+		return self
+	}
+
 	/// A producer for Signals that will send the property's current
 	/// value, followed by all changes over time, then complete when the
 	/// property has deinitialized or has no further changes.
@@ -649,6 +660,7 @@ extension Property where Value: OptionalProtocol {
 /// A mutable property of type `Value` that allows observation of its changes.
 ///
 /// Instances of this class are thread-safe.
+@propertyWrapper
 public final class MutableProperty<Value>: ComposableMutablePropertyProtocol {
 	private let token: Lifetime.Token
 	private let observer: Signal<Value, Never>.Observer
@@ -663,6 +675,17 @@ public final class MutableProperty<Value>: ComposableMutablePropertyProtocol {
 		set { modify { $0 = newValue } }
 	}
 
+	@inlinable
+	public var wrappedValue: Value {
+		get { value }
+		set { value = newValue }
+	}
+
+	@inlinable
+	public var projectedValue: MutableProperty<Value> {
+		return self
+	}
+
 	/// The lifetime of the property.
 	public let lifetime: Lifetime
 
@@ -696,6 +719,14 @@ public final class MutableProperty<Value>: ComposableMutablePropertyProtocol {
 		box = PropertyBox(initialValue)
 	}
 
+	/// Initializes a mutable property that first takes on `initialValue`
+	///
+	/// - parameters:
+	///   - initialValue: Starting value for the mutable property.
+	public convenience init(wrappedValue: Value) {
+		self.init(wrappedValue)
+	}
+
 	/// Atomically replaces the contents of the variable.
 	///
 	/// - parameters:

Tests/ReactiveSwiftTests/PropertySpec.swift

@@ -310,9 +310,40 @@ class PropertySpec: QuickSpec {
 					}
 				}
 			}
+
+			it("can be used as property wrapper") {
+				struct Container {
+					@MutableProperty var counter = 0
+				}
+
+				let container = Container()
+				expect(container.counter) == 0
+
+				container.counter += 1
+				expect(container.counter) == 1
+
+				container.$counter.modify { $0 += 2 }
+				expect(container.counter) == 3
+			}
 		}
 
 		describe("Property") {
+			it("can be used as property wrapper") {
+				struct Container {
+					@Property var counter: Int
+				}
+
+				let mutableCounter = MutableProperty(0)
+				let container = Container(counter: Property(capturing: mutableCounter))
+				expect(container.counter) == 0
+
+				mutableCounter.value = 1
+				expect(container.counter) == 1
+
+				mutableCounter.modify { $0 += 2 }
+				expect(container.counter) == 3
+			}
+
 			describe("constant property") {
 				it("should have the value given at initialization") {
 					let constantProperty = Property(value: initialPropertyValue)