add indexOf(value) and indexOf(value, offset)

primitiveCollections/src/main/java/org/lucares/collections/IntList.java

@@ -26,7 +26,6 @@ public final class IntList implements Serializable, Cloneable {
 	// TODO add removeRange
 	// TODO add replace
 	// TODO add lastIndexOf
-	// TODO add indexOf
 	// TODO remove bounds checks that are handled by java, e.g. negative indices
 	// TODO toString
 
@@ -352,6 +351,39 @@ public final class IntList implements Serializable, Cloneable {
 		return StreamSupport.intStream(spliterator, true);
 	}
 
+	/**
+	 * Returns the index of the first occurrence of {@code value}, or -1 if it does
+	 * not exist.
+	 *
+	 * @param value
+	 *            the value
+	 * @return the index, or -1
+	 */
+	public int indexOf(final int value) {
+		return indexOf(value, 0);
+	}
+
+	/**
+	 * Returns the index of the first occurrence of {@code value} starting at the
+	 * {@code offset}'s element, or -1 if it does not exist.
+	 *
+	 * @param value
+	 *            the value
+	 * @param offset
+	 *            the offset
+	 * @return the index, or -1
+	 * @throws ArrayIndexOutOfBoundsException
+	 *             if offset is negative, or larger than the size of the list
+	 */
+	public int indexOf(final int value, final int offset) {
+		for (int i = offset; i < index; i++) {
+			if (data[i] == value) {
+				return i;
+			}
+		}
+		return -1;
+	}
+
 	@Override
 	public String toString() {