Support Delegate and MulticastDelegate as generic type constraints (#…

…24443) * Support Delegate and Multicast delegates as generic type constraints * More tests
dotnet · Jan 29, 2018 · c23d361 · c23d361
1 parent fcacbc5
commit c23d361
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Showing 24 changed files with 1,290 additions and 14 deletions.
diff --git a/src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs b/src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs
@@ -171,12 +171,17 @@ private TypeParameterConstraintClause BindTypeParameterConstraints(
 
                                 if ((constraints & (TypeParameterConstraintKind.ReferenceType | TypeParameterConstraintKind.ValueType)) != 0)
                                 {
-                                    // System.Enum is allowed to exist with class and struct constraints
-                                    if (type.SpecialType != SpecialType.System_Enum)
+                                    switch (type.SpecialType)
                                     {
-                                        // "'{0}': cannot specify both a constraint class and the 'class' or 'struct' constraint"
-                                        Error(diagnostics, ErrorCode.ERR_RefValBoundWithClass, syntax, type);
-                                        continue;
+                                        case SpecialType.System_Enum:
+                                        case SpecialType.System_Delegate:
+                                        case SpecialType.System_MulticastDelegate:
+                                            break;
+
+                                        default:
+                                            // "'{0}': cannot specify both a constraint class and the 'class' or 'struct' constraint"
+                                            Error(diagnostics, ErrorCode.ERR_RefValBoundWithClass, syntax, type);
+                                            continue;
                                     }
                                 }
                             }
@@ -204,10 +209,13 @@ private static bool IsValidConstraintType(TypeConstraintSyntax syntax, TypeSymbo
                     CheckFeatureAvailability(syntax, MessageID.IDS_FeatureEnumGenericTypeConstraint, diagnostics);
                     break;
 
-                case SpecialType.System_Object:
-                case SpecialType.System_ValueType:
                 case SpecialType.System_Delegate:
                 case SpecialType.System_MulticastDelegate:
+                    CheckFeatureAvailability(syntax, MessageID.IDS_FeatureDelegateGenericTypeConstraint, diagnostics);
+                    break;
+
+                case SpecialType.System_Object:
+                case SpecialType.System_ValueType:
                 case SpecialType.System_Array:
                     // "Constraint cannot be special class '{0}'"
                     Error(diagnostics, ErrorCode.ERR_SpecialTypeAsBound, syntax, type);

diff --git a/src/Compilers/CSharp/Portable/CSharpResources.Designer.cs b/src/Compilers/CSharp/Portable/CSharpResources.Designer.cs
diff --git a/src/Compilers/CSharp/Portable/CSharpResources.resx b/src/Compilers/CSharp/Portable/CSharpResources.resx
@@ -5249,4 +5249,7 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="IDS_FeatureEnumGenericTypeConstraint" xml:space="preserve">
     <value>enum generic type constraints</value>
   </data>
+  <data name="IDS_FeatureDelegateGenericTypeConstraint" xml:space="preserve">
+    <value>delegate generic type constraints</value>
+  </data>
 </root>
diff --git a/src/Compilers/CSharp/Portable/Errors/MessageID.cs b/src/Compilers/CSharp/Portable/Errors/MessageID.cs
@@ -148,6 +148,7 @@ internal enum MessageID
 
         IDS_FeatureAttributesOnBackingFields = MessageBase + 12731,
         IDS_FeatureEnumGenericTypeConstraint = MessageBase + 12732,
+        IDS_FeatureDelegateGenericTypeConstraint = MessageBase + 12733,
     }
 
     // Message IDs may refer to strings that need to be localized.
@@ -190,6 +191,7 @@ internal static LanguageVersion RequiredVersion(this MessageID feature)
                 // C# 7.3 features.
                 case MessageID.IDS_FeatureAttributesOnBackingFields: // semantic check
                 case MessageID.IDS_FeatureEnumGenericTypeConstraint: // semantic check
+                case MessageID.IDS_FeatureDelegateGenericTypeConstraint: // semantic check
                     return LanguageVersion.CSharp7_3;
 
                 // C# 7.2 features.

diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.cs.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.cs.xlf
@@ -8605,6 +8605,11 @@ Pokud chcete odstranit toto varování, můžete místo toho použít /reference
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.de.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.de.xlf
@@ -8605,6 +8605,11 @@ Um die Warnung zu beheben, können Sie stattdessen /reference verwenden (Einbett
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.es.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.es.xlf
@@ -8605,6 +8605,11 @@ Para eliminar la advertencia puede usar /reference (establezca la propiedad Embe
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.fr.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.fr.xlf
@@ -8605,6 +8605,11 @@ Pour supprimer l'avertissement, vous pouvez utiliser la commande /reference (dé
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.it.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.it.xlf
@@ -8605,6 +8605,11 @@ Per rimuovere l'avviso, è invece possibile usare /reference (impostare la propr
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ja.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ja.xlf
@@ -8605,6 +8605,11 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ko.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ko.xlf
@@ -8605,6 +8605,11 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.pl.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.pl.xlf
@@ -8605,6 +8605,11 @@ Aby usunąć ostrzeżenie, możesz zamiast tego użyć opcji /reference (ustaw w
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.pt-BR.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.pt-BR.xlf
@@ -8605,6 +8605,11 @@ Para incorporar informações de tipo de interoperabilidade para os dois assembl
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ru.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ru.xlf
@@ -8605,6 +8605,11 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.tr.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.tr.xlf
@@ -8605,6 +8605,11 @@ Uyarıyı kaldırmak için, /reference kullanabilirsiniz (Birlikte Çalışma T
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hans.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hans.xlf
@@ -8605,6 +8605,11 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hant.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hant.xlf
@@ -8605,6 +8605,11 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
         <target state="new">enum generic type constraints</target>
         <note />
       </trans-unit>
+      <trans-unit id="IDS_FeatureDelegateGenericTypeConstraint">
+        <source>delegate generic type constraints</source>
+        <target state="new">delegate generic type constraints</target>
+        <note />
+      </trans-unit>
     </body>
   </file>
 </xliff>