[C++] Library needed to validate and read XML

I am about to begin a major new project which requires a great deal of XML processing. Some of our other projects have involved using "eXpat" to read XML, but this time I also need to validate the XML against a schema.

eXpat is not a validating XML engine, it is just a reader.

So my question is, can you recommend an alternative to eXpat which will do both validation against a schema and also allows efficient XML reading?

I'd probably settle for a decent library that will do just the schema validation, and I'd just use eXpat to do the reading, but it would be more convenient to have one library that can do both.

Any ideas?

VTDParser is extremely fast and powerful.