cgen: fix arr.insert(0, [1,2,3]) and arr.prepend([1,2,3])

vlib/builtin/array.v

@@ -136,11 +136,7 @@ pub fn (mut a array) sort_with_compare(compare voidptr) {
 	C.qsort(a.data, a.len, a.element_size, compare)
 }
 
-// TODO array.insert is broken
-// Cannot pass literal or primitive type as it cannot be cast to voidptr.
-// In the current state only that would work:
-// i := 3
-// a.insert(0, &i)
+// array.insert
 pub fn (mut a array) insert(i int, val voidptr) {
 	$if !no_bounds_checking? {
 		if i < 0 || i > a.len {
@@ -154,12 +150,30 @@ pub fn (mut a array) insert(i int, val voidptr) {
 	a.len++
 }
 
-// TODO array.prepend is broken
-// It depends on array.insert
+// array.insert_many
+pub fn (mut a array) insert_many(i int, val voidptr, size int) {
+	$if !no_bounds_checking? {
+		if i < 0 || i > a.len {
+			panic('array.insert_many: index out of range (i == $i, a.len == $a.len)')
+		}
+	}
+	a.ensure_cap(a.len + size)
+	elem_size := a.element_size
+	C.memmove(byteptr(a.data) + (i + size) * elem_size, byteptr(a.data) + i * elem_size, (a.len - i) * elem_size)
+	C.memcpy(byteptr(a.data) + i * elem_size, val, size * elem_size)
+	a.len += size
+}
+
+// array.prepend
 pub fn (mut a array) prepend(val voidptr) {
 	a.insert(0, val)
 }
 
+// array.prepend_many
+pub fn (mut a array) prepend_many(val voidptr, size int) {
+	a.insert_many(0, val, size)
+}
+
 // array.delete deletes array element at the given index
 pub fn (mut a array) delete(i int) {
 	$if !no_bounds_checking? {

vlib/builtin/array_test.v

@@ -134,6 +134,15 @@ fn test_insert() {
 	assert b[0] == f64(1.1)
 }
 
+fn test_insert_many() {
+	mut a := [3, 4]
+	a.insert(0, [1, 2])
+	assert a == [1,2,3,4]
+	b := [5,6]
+	a.insert(1, b)
+	assert a == [1,5,6,2,3,4]
+}
+
 fn test_prepend() {
 	mut a := []int{}
 	assert a.len == 0
@@ -147,6 +156,15 @@ fn test_prepend() {
 	assert b[0] == f64(1.1)
 }
 
+fn test_prepend_many() {
+	mut a := [3,4]
+	a.prepend([1,2])
+	assert a == [1,2,3,4]
+	b := [5,6]
+	a.prepend(b)
+	assert a == [5,6,1,2,3,4]
+}
+
 fn test_strings() {
 	a := ['a', 'b', 'c']
 	assert a.str() == "['a', 'b', 'c']"
@@ -166,7 +184,6 @@ fn test_compare_ints() {
 }
 */
 
-
 fn test_repeat() {
 	{
 		a := [0].repeat(5)