/**
* Adds all elements in {@code iterable} to {@code collection}.
*
* @return {@code true} if {@code collection} was modified as a result of this operation.
*/
public static <T> boolean addAll(Collection<T> addTo, Iterable<? extends T> elementsToAdd) {
if (elementsToAdd instanceof Collection) {
Collection<? extends T> c = Collections2.cast(elementsToAdd);
return addTo.addAll(c);
}
return Iterators.addAll(addTo, checkNotNull(elementsToAdd).iterator());
}
@Override
public boolean putAll(K key, Iterable<? extends V> values) {
checkNotNull(values);
// make sure we only call values.iterator() once
// and we only call get(key) if values is nonempty
if (values instanceof Collection) {
Collection<? extends V> valueCollection = (Collection<? extends V>) values;
return !valueCollection.isEmpty() && get(key).addAll(valueCollection);
} else {
Iterator<? extends V> valueItr = values.iterator();
return valueItr.hasNext() && Iterators.addAll(get(key), valueItr);
}
}
/**
* A sensible definition of {@link #addAll} in terms of {@link #add}. If you override {@link
* #add}, you may wish to override {@link #addAll} to forward to this implementation.
*
* @since 7.0
*/
protected boolean standardAddAll(Collection<? extends E> collection) {
return Iterators.addAll(this, collection.iterator());
}