/**
* Validates that a type is extendable, i.e. is not an array, a primitive type or a {@code final}
* type.
*
* @param typeDescription The type to validate.
* @param <T> The actual type of the validated instance.
* @return The input value.
*/
public static <T extends GenericTypeDescription> T isExtendable(T typeDescription) {
if (!EXTENDABLE_TYPES.contains(typeDescription.getSort())) {
throw new IllegalArgumentException("Cannot extend generic type: " + typeDescription);
} else if (isDefineable(typeDescription.asErasure()).isFinal()) {
throw new IllegalArgumentException("Cannot extend a final type: " + typeDescription);
}
return typeDescription;
}
/**
* Validates that a type represents an actual type or {@code void}, i.e. not a wildcard.
*
* @param typeDescription The type to validate.
* @param <T> The actual type of the argument.
* @return The input value.
*/
public static <T extends GenericTypeDescription> T isActualTypeOrVoid(T typeDescription) {
if (typeDescription.getSort().isWildcard()) {
throw new IllegalArgumentException("Not a top-level type: " + typeDescription);
}
return typeDescription;
}
