Dynamic API: Allow setting an AnyPointer field from any pointer type.

c++/src/capnp/dynamic-test.c++

@@ -158,6 +158,37 @@ TEST(DynamicApi, AnyPointers) {
     checkList<uint32_t>(root.getAnyPointerField().getAs<DynamicList>(
         Schema::from<List<uint32_t>>()), {123u, 456u, 789u, 123456789u});
   }
+
+  // Setting an AnyPointer to various types should work.
+  toDynamic(root).set("anyPointerField", capnp::Text::Reader("foo"));
+  EXPECT_EQ("foo", root.getAnyPointerField().getAs<Text>());
+
+  {
+    auto orphan = builder.getOrphanage().newOrphan<TestAllTypes>();
+    initTestMessage(orphan.get());
+    toDynamic(root).set("anyPointerField", orphan.getReader());
+    checkTestMessage(root.getAnyPointerField().getAs<TestAllTypes>());
+
+    toDynamic(root).adopt("anyPointerField", kj::mv(orphan));
+    checkTestMessage(root.getAnyPointerField().getAs<TestAllTypes>());
+  }
+
+  {
+    auto lorphan = builder.getOrphanage().newOrphan<List<uint32_t>>(3);
+    lorphan.get().set(0, 12);
+    lorphan.get().set(1, 34);
+    lorphan.get().set(2, 56);
+    toDynamic(root).set("anyPointerField", lorphan.getReader());
+    auto l = root.getAnyPointerField().getAs<List<uint32_t>>();
+    ASSERT_EQ(3, l.size());
+    EXPECT_EQ(12, l[0]);
+    EXPECT_EQ(34, l[1]);
+    EXPECT_EQ(56, l[2]);
+  }
+
+  // Just compile this one.
+  toDynamic(root).set("anyPointerField", Capability::Client(nullptr));
+  root.getAnyPointerField().getAs<Capability>();
 }
 
 TEST(DynamicApi, DynamicAnyPointers) {

c++/src/capnp/dynamic.c++

@@ -558,10 +558,41 @@ void DynamicStruct::Builder::set(StructSchema::Field field, const DynamicValue::
           return;
         }
 
-        case schema::Type::ANY_POINTER:
-          AnyPointer::Builder(builder.getPointerField(slot.getOffset() * POINTERS))
-                 .set(value.as<AnyPointer>());
+        case schema::Type::ANY_POINTER: {
+          auto target = AnyPointer::Builder(builder.getPointerField(slot.getOffset() * POINTERS));
+
+          switch (value.getType()) {
+            case DynamicValue::Type::TEXT:
+              target.setAs<Text>(value.as<Text>());
+              return;
+            case DynamicValue::Type::DATA:
+              target.setAs<Data>(value.as<Data>());
+              return;
+            case DynamicValue::Type::LIST:
+              target.setAs<DynamicList>(value.as<DynamicList>());
+              return;
+            case DynamicValue::Type::STRUCT:
+              target.setAs<DynamicStruct>(value.as<DynamicStruct>());
+              return;
+            case DynamicValue::Type::CAPABILITY:
+              target.setAs<DynamicCapability>(value.as<DynamicCapability>());
               return;
+            case DynamicValue::Type::ANY_POINTER:
+              target.set(value.as<AnyPointer>());
+              return;
+
+            case DynamicValue::Type::UNKNOWN:
+            case DynamicValue::Type::VOID:
+            case DynamicValue::Type::BOOL:
+            case DynamicValue::Type::INT:
+            case DynamicValue::Type::UINT:
+            case DynamicValue::Type::FLOAT:
+            case DynamicValue::Type::ENUM:
+              KJ_FAIL_ASSERT("Value type mismatch; expected AnyPointer");
+          }
+
+          KJ_UNREACHABLE;
+        }
 
         case schema::Type::INTERFACE: {
           auto interfaceType = type.asInterface();