diff --git a/vlib/builtin/array.v b/vlib/builtin/array.v
index 99055f3958..f1734d8dfe 100644
--- a/vlib/builtin/array.v
+++ b/vlib/builtin/array.v
@@ -488,6 +488,43 @@ pub fn (a &array) free() {
 	unsafe { free(&byte(a.data) - a.offset) }
 }
 
+// filter creates a new array with all elements that pass the test implemented by the provided function
+pub fn (a array) filter(predicate fn (voidptr) bool) array
+
+struct ZZZTmp1 {}
+
+// any tests whether at least one element in the array passes the test implemented by the
+// provided function. It returns true if, in the array, it finds an element for which the provided
+// function returns true; otherwise it returns false. It doesn't modify the array
+pub fn (a array) any(predicate fn (voidptr) bool) bool
+
+struct ZZZTmp2 {}
+
+// all tests whether all elements in the array pass the test implemented by the provided function
+pub fn (a array) all(predicate fn (voidptr) bool) bool
+
+struct ZZZTmp3 {}
+
+// map creates a new array populated with the results of calling a provided function
+// on every element in the calling array
+pub fn (a array) map(callback fn (voidptr) voidptr) array
+
+struct ZZZTmp4 {}
+
+// sort sorts an array in place in ascending order.
+pub fn (mut a array) sort(callback fn (voidptr, voidptr) int)
+
+struct ZZZTmp5 {}
+
+// contains determines whether an array includes a certain value among its entries
+pub fn (a array) contains(val voidptr) bool
+
+struct ZZZTmp6 {}
+
+// index returns the first index at which a given element can be found in the array
+// or -1 if the value is not found.
+pub fn (a array) index(value voidptr) int
+
 [unsafe]
 pub fn (mut a []string) free() {
 	$if prealloc {