Add the IProgress<T> interface for provider interface callbacks

Author: sharwell

src/corelib/Core/IProgress`1.cs

@@ -0,0 +1,22 @@
+namespace net.openstack.Core
+{
+    /// <summary>
+    /// Defines a provider for progress updates.
+    /// </summary>
+    /// <typeparam name="T">The type of progress update value.</typeparam>
+    /// <preliminary/>
+    public interface IProgress<
+#if NET35
+        T
+#else
+        in T
+#endif
+        >
+    {
+        /// <summary>
+        /// Reports a progress update.
+        /// </summary>
+        /// <param name="value">The value of the updated progress.</param>
+        void Report(T value);
+    }
+}

src/corelib/corelib.v3.5.csproj

@@ -109,6 +109,7 @@
     <Compile Include="Core\Exceptions\VolumeEnteredErrorStateException.cs" />
     <Compile Include="Core\ExtensibleEnum`1.cs" />
     <Compile Include="Core\InternalTaskExtensions.cs" />
+    <Compile Include="Core\IProgress`1.cs" />
     <Compile Include="Core\NamespaceDoc.cs" />
     <Compile Include="Core\ParallelExtensionsExtras\TaskCompletionSourceExtensions.cs" />
     <Compile Include="Core\ParallelExtensionsExtras\TaskExtrasExtensions.cs" />

src/corelib/corelib.v4.0.csproj

@@ -99,6 +99,7 @@
     <Compile Include="Core\Exceptions\VolumeEnteredErrorStateException.cs" />
     <Compile Include="Core\ExtensibleEnum`1.cs" />
     <Compile Include="Core\InternalTaskExtensions.cs" />
+    <Compile Include="Core\IProgress`1.cs" />
     <Compile Include="Core\NamespaceDoc.cs" />
     <Compile Include="Core\ParallelExtensionsExtras\TaskCompletionSourceExtensions.cs" />
     <Compile Include="Core\ParallelExtensionsExtras\TaskExtrasExtensions.cs" />