Improved documentation

README.md

@@ -153,11 +153,14 @@ will return:
 <a href="#fromjson">fromJson</a>
 <a href="#get">get</a>
 <a href="#getiterator">getIterator</a>
+<a href="#grep">grep</a>
 <a href="#groupby">groupBy</a>
 <a href="#has">has</a>
 <a href="#in">in</a>
 <a href="#includes">includes</a>
 <a href="#index">index</a>
+<a href="#insertAfter">insertAfter</a>
+<a href="#insertBefore">insertBefore</a>
 <a href="#intersect">intersect</a>
 <a href="#intersectassoc">intersectAssoc</a>
 <a href="#intersectkeys">intersectKeys</a>
@@ -271,6 +274,7 @@ will return:
 
 * [concat()](#concat) : Adds all elements with new keys
 * [insertAfter()](#insertAfter) : Inserts the value after the given element
+* [insertBefore()](#insertBefore) : Inserts the value before the given element
 * [merge()](#merge) : Combines elements overwriting existing ones
 * [pad()](#pad) : Fill up to the specified length with the given value
 * [prepend()](#prepend) : Adds an element at the beginning
@@ -2702,7 +2706,7 @@ Returns the numerical index of the value.
 public function pos( $value ) : ?int
 ```
 
-* @param \Closure&#124;mixed $value Value to search for or function with (item, key) parameters return TRUE if value is found
+* @param \Closure&#124;string|int $value Value to search for or function with (item, key) parameters return TRUE if value is found
 * @return int&#124;null Position of the found value (zero based) or NULL if not found
 
 **Examples:**

src/Map.php

@@ -2332,7 +2332,7 @@ public function pop()
 	 * Both examples will return "1" because the value "b" is at the second position
 	 * and the returned index is zero based so the first item has the index "0".
 	 *
-	 * @param \Closure|mixed $value Value to search for or function with (item, key) parameters return TRUE if value is found
+	 * @param \Closure|string|int $value Value to search for or function with (item, key) parameters return TRUE if value is found
 	 * @return int|null Position of the found value (zero based) or NULL if not found
 	 */
 	public function pos( $value ) : ?int

tests/MapTest.php

@@ -1742,6 +1742,13 @@ public function testPos()
 		$m = new Map( [4 => 'a', 8 => 'b'] );
 
 		$this->assertEquals( 1, $m->pos( 'b' ) );
+	}
+
+
+	public function testPosClosure()
+	{
+		$m = new Map( [4 => 'a', 8 => 'b'] );
+
 		$this->assertEquals( 1, $m->pos( function( $item, $key ) {
 			return $item === 'b';
 		} ) );