Better check that schema matches exactly here.

c++/src/capnproto/dynamic.c++

@@ -281,17 +281,11 @@ void DynamicUnion::Builder::setObjectDiscriminant(StructSchema::Member member) {
 
 // =======================================================================================
 
-void DynamicStruct::Reader::verifyTypeId(uint64_t id) {
-  VALIDATE_INPUT(id == schema.getProto().getId(),
-                 "Type mismatch when using DynamicStruct::Reader::as().") {
-    // Go on with bad type ID.
-  }
+void DynamicStruct::Reader::verifySchema(StructSchema expected) {
+  PRECOND(schema == expected, "Type mismatch when using DynamicStruct::Reader::as().");
 }
-void DynamicStruct::Builder::verifyTypeId(uint64_t id) {
-  VALIDATE_INPUT(id == schema.getProto().getId(),
-                 "Type mismatch when using DynamicStruct::Builder::as().") {
-    // Go on with bad type ID.
-  }
+void DynamicStruct::Builder::verifySchema(StructSchema expected) {
+  PRECOND(schema == expected, "Type mismatch when using DynamicStruct::Builder::as().");
 }
 
 DynamicValue::Reader DynamicStruct::Reader::get(StructSchema::Member member) {

c++/src/capnproto/dynamic.h

@@ -267,7 +267,7 @@ private:
   inline Reader(StructSchema schema, internal::StructReader reader)
       : schema(schema), reader(reader) {}
 
-  void verifyTypeId(uint64_t id);
+  void verifySchema(StructSchema expected);
 
   static DynamicValue::Reader getImpl(internal::StructReader reader, StructSchema::Member member);
 
@@ -344,7 +344,7 @@ private:
   inline Builder(StructSchema schema, internal::StructBuilder builder)
       : schema(schema), builder(builder) {}
 
-  void verifyTypeId(uint64_t id);
+  void verifySchema(StructSchema expected);
 
   static DynamicValue::Builder getImpl(
       internal::StructBuilder builder, StructSchema::Member member);
@@ -858,14 +858,14 @@ template <typename T>
 typename T::Reader DynamicStruct::Reader::as() {
   static_assert(kind<T>() == Kind::STRUCT,
                 "DynamicStruct::Reader::as<T>() can only convert to struct types.");
-  verifyTypeId(typeId<T>());
+  verifySchema(Schema::from<T>());
   return typename T::Reader(reader);
 }
 template <typename T>
 typename T::Builder DynamicStruct::Builder::as() {
   static_assert(kind<T>() == Kind::STRUCT,
                 "DynamicStruct::Builder::as<T>() can only convert to struct types.");
-  verifyTypeId(typeId<T>());
+  verifySchema(Schema::from<T>());
   return typename T::Builder(builder);
 }