How to use

ElementUtils$AnnotationValueVisitorImpl

in

com.oracle.truffle.dsl.processor.java

public static <T> T resolveAnnotationValue(Class<T> expectedType, AnnotationValue value) {
  if (value == null) {
    return null;
  }
  Object unboxedValue = value.accept(new AnnotationValueVisitorImpl(), null);
  if (unboxedValue != null) {
    if (expectedType == TypeMirror.class && unboxedValue instanceof String) {
      return null;
    }
    if (!expectedType.isAssignableFrom(unboxedValue.getClass())) {
      throw new ClassCastException(unboxedValue.getClass().getName() + " not assignable from " + expectedType.getName());
    }
  }
  return expectedType.cast(unboxedValue);
}

@SuppressWarnings({"unchecked"})
private static <T> T resolveAnnotationValue(Class<T> expectedType, AnnotationValue value) {
  if (value == null) {
    return null;
  }
  Object unboxedValue = value.accept(new AnnotationValueVisitorImpl(), null);
  if (unboxedValue != null) {
    if (expectedType == TypeMirror.class && unboxedValue instanceof String) {
      return null;
    }
    if (!expectedType.isAssignableFrom(unboxedValue.getClass())) {
      throw new ClassCastException(unboxedValue.getClass().getName() + " not assignable from " + expectedType.getName());
    }
  }
  return (T) unboxedValue;
}