diff --git a/vlib/bitfield/bitfield.v b/vlib/bitfield/bitfield.v
index e7ae271145..1066b019a3 100644
--- a/vlib/bitfield/bitfield.v
+++ b/vlib/bitfield/bitfield.v
@@ -68,7 +68,7 @@ pub fn new(size int) BitField {
 	output := BitField{
 		size: size
 		//field: *u32(calloc(bitnslots(size) * slot_size / 8))
-		field: [u32(0)].repeat(bitnslots(size))
+		field: []u32{len:bitnslots(size)}
 	}
 	return output
 }
@@ -394,7 +394,7 @@ pub fn (mut instance BitField) resize(new_size int) {
 	new_bitnslots := bitnslots(new_size)
 	old_size := instance.size
 	old_bitnslots := bitnslots(old_size)
-	mut field := [u32(0)].repeat(new_bitnslots)
+	mut	field := []u32{len:new_bitnslots}
 	for i := 0; i < old_bitnslots && i < new_bitnslots; i++ {
 		field[i] = instance.field[i]
 	}
diff --git a/vlib/bitfield/bitfield_test.v b/vlib/bitfield/bitfield_test.v
index 8e486436b5..6b305758a6 100644
--- a/vlib/bitfield/bitfield_test.v
+++ b/vlib/bitfield/bitfield_test.v
@@ -1,7 +1,6 @@
 import bitfield
 
 import rand
-import time
 
 fn test_bf_new_size() {
 	instance := bitfield.new(75)
diff --git a/vlib/builtin/bare/.checks/forkedtest/forkedtest.v b/vlib/builtin/bare/.checks/forkedtest/forkedtest.v
index 9f3f7aacd0..6d9272c7ec 100644
--- a/vlib/builtin/bare/.checks/forkedtest/forkedtest.v
+++ b/vlib/builtin/bare/.checks/forkedtest/forkedtest.v
@@ -7,7 +7,7 @@ pub fn run (op fn(), label string, code Wi_si_code, status int) int {
 		sys_exit(0)
 	}
 
-	siginfo := [0].repeat(int(Sig_index.si_size))
+	siginfo := []int{len:int(Sig_index.si_size)}
 
 	e := sys_waitid(.p_pid, child, intptr(&siginfo[0]), .wexited, 0)
 
diff --git a/vlib/builtin/bare/.checks/linuxsys/linuxsys.v b/vlib/builtin/bare/.checks/linuxsys/linuxsys.v
index a8625d9da7..cca5cb62fd 100644
--- a/vlib/builtin/bare/.checks/linuxsys/linuxsys.v
+++ b/vlib/builtin/bare/.checks/linuxsys/linuxsys.v
@@ -40,7 +40,7 @@ fn check_read_write_pipe() {
 	//		sys_read
 	//		sys_close
 	//
-	buffer0 := [byte(0)].repeat(128)
+	buffer0 := []byte{len:(128)}
 	buffer := byteptr(buffer0.data)
 
 	fd := [-1, -1]
@@ -87,7 +87,7 @@ fn check_read_file() {
 			sys_close
 			sys_open
 	*/
-	buffer0 := [byte(0)].repeat(128)
+	buffer0 := []byte{len:(128)}
 	buffer := byteptr(buffer0.data)
 
 	test_file := "sample_text1.txt"
diff --git a/vlib/builtin/bare/.checks/string/string.v b/vlib/builtin/bare/.checks/string/string.v
index 864d201b39..54c06e7eff 100644
--- a/vlib/builtin/bare/.checks/string/string.v
+++ b/vlib/builtin/bare/.checks/string/string.v
@@ -8,7 +8,7 @@ fn check_string_eq () {
 }
 
 fn check_i64_tos() {
-	buffer0 := [byte(0)].repeat(128)
+	buffer0 := []byte{len:(128)}
 	buffer := byteptr(buffer0.data)
 
 	s0 := i64_tos(buffer, 70, 140, 10)
diff --git a/vlib/builtin/int.v b/vlib/builtin/int.v
index 718f47de03..250dbb3c65 100644
--- a/vlib/builtin/int.v
+++ b/vlib/builtin/int.v
@@ -399,7 +399,7 @@ pub fn (c byte) is_capital() bool {
 }
 
 pub fn (b []byte) clone() []byte {
-	mut res := [byte(0)].repeat(b.len)
+	mut res := []byte{len: b.len}
 	//mut res := make([]byte, {repeat:b.len})
 	for i in 0..b.len {
 		res[i] = b[i]
diff --git a/vlib/builtin/sorted_map.v b/vlib/builtin/sorted_map.v
index 5e96466807..518649d30c 100644
--- a/vlib/builtin/sorted_map.v
+++ b/vlib/builtin/sorted_map.v
@@ -379,7 +379,7 @@ fn (n &mapnode) subkeys(mut keys []string, at int) int {
 }
 
 pub fn (m &SortedMap) keys() []string {
-	mut keys := [''].repeat(m.len)
+	mut keys := []string{len:m.len}
 	if isnil(m.root) || m.root.len == 0 {
 		return keys
 	}
diff --git a/vlib/builtin/string.v b/vlib/builtin/string.v
index bd28c01503..3f9681e602 100644
--- a/vlib/builtin/string.v
+++ b/vlib/builtin/string.v
@@ -595,7 +595,7 @@ fn (s string) index_kmp(p string) int {
 	if p.len > s.len {
 		return -1
 	}
-	mut prefix := [0].repeat(p.len)
+	mut prefix := []int{len:p.len}
 	mut j := 0
 	for i := 1; i < p.len; i++ {
 		for p.str[j] != p.str[i] && j > 0 {
@@ -1326,7 +1326,7 @@ pub fn (s string) bytes() []byte {
 	if s.len == 0 {
 		return []
 	}
-	mut buf := [byte(0)].repeat(s.len)
+	mut buf := []byte{ len:s.len }
 	C.memcpy(buf.data, s.str, s.len)
 	return buf
 }
diff --git a/vlib/crypto/aes/aes_cbc.v b/vlib/crypto/aes/aes_cbc.v
index 9694bc7c87..2623172dce 100644
--- a/vlib/crypto/aes/aes_cbc.v
+++ b/vlib/crypto/aes/aes_cbc.v
@@ -30,7 +30,7 @@ fn new_aes_cbc(b AesCipher, iv []byte) AesCbc {
 		b:          b,
 		block_size: b.block_size(),
 		iv:         iv.clone(),
-		tmp:        [byte(0)].repeat(b.block_size()),
+		tmp:        []byte{len:(b.block_size()),}
 	}
 }
 
diff --git a/vlib/crypto/aes/cypher_generic.v b/vlib/crypto/aes/cypher_generic.v
index bd7f3b593d..724334d80a 100644
--- a/vlib/crypto/aes/cypher_generic.v
+++ b/vlib/crypto/aes/cypher_generic.v
@@ -9,8 +9,8 @@ module aes
 fn new_cipher_generic(key []byte) AesCipher {
 	n := key.len + 28
 	mut c := AesCipher{
-		enc: [u32(0)].repeat(n)
-		dec: [u32(0)].repeat(n)
+		enc: []u32{len:(n)}
+		dec: []u32{len:(n)}
 	}
 	expand_key_generic(key, mut c.enc, mut c.dec)
 	return c
diff --git a/vlib/crypto/md5/md5.v b/vlib/crypto/md5/md5.v
index d822175200..1f48adff9e 100644
--- a/vlib/crypto/md5/md5.v
+++ b/vlib/crypto/md5/md5.v
@@ -38,8 +38,8 @@ mut:
 }
 
 fn (mut d Digest) reset() {
-	d.s = [u32(0)].repeat(4)
-	d.x = [byte(0)].repeat(block_size)
+	d.s = []u32{len:(4)}
+	d.x = []byte{len:(block_size)}
     d.s[0] = u32(init0)
 	d.s[1] = u32(init1)
 	d.s[2] = u32(init2)
@@ -105,7 +105,7 @@ pub fn (mut d Digest) checksum() []byte {
 	//
 	// 1 byte end marker :: 0-63 padding bytes :: 8 byte length
 	// tmp := [1 + 63 + 8]byte{0x80}
-    mut tmp := [byte(0)].repeat(1 + 63 + 8)
+    mut tmp := []byte{len:(1 + 63 + 8)}
 	tmp[0] = 0x80
 	pad := ((55 - d.len) % 64) // calculate number of padding bytes
 	binary.little_endian_put_u64(mut tmp[1+pad..], d.len<<3) // append length in bits
@@ -117,7 +117,7 @@ pub fn (mut d Digest) checksum() []byte {
 		panic('d.nx != 0')
 	}
 
-    digest := [byte(0)].repeat(size)
+    digest := []byte{len:(size)}
 
 	binary.little_endian_put_u32(mut digest, d.s[0])
 	binary.little_endian_put_u32(mut digest[4..], d.s[1])
diff --git a/vlib/crypto/rand/utils.v b/vlib/crypto/rand/utils.v
index 14cfdb84c2..14796acb84 100644
--- a/vlib/crypto/rand/utils.v
+++ b/vlib/crypto/rand/utils.v
@@ -38,7 +38,7 @@ pub fn int_u64(max u64) ?u64 {
 
 fn bytes_to_u64(b []byte) []u64 {
 	ws := 64/8
-	mut z := [u64(0)].repeat((b.len + ws - 1) / ws)
+	mut z := []u64{len:((b.len + ws - 1) / ws)}
 	mut i := b.len
 	for k := 0; i >= ws; k++ {
 		z[k] = binary.big_endian_u64(b[i-ws..i])
diff --git a/vlib/crypto/rc4/rc4.v b/vlib/crypto/rc4/rc4.v
index 2f97c560bb..798fe30119 100644
--- a/vlib/crypto/rc4/rc4.v
+++ b/vlib/crypto/rc4/rc4.v
@@ -30,7 +30,7 @@ pub fn new_cipher(key []byte) ?Cipher {
 		return error('crypto.rc4: invalid key size ' + key.len.str())
 	}
 	mut c := Cipher{
-		s: [u32(0)].repeat(256)
+		s: []u32{len:(256)}
 	}
 	for i in 0..256 {
 		c.s[i] = u32(i)
diff --git a/vlib/crypto/sha1/sha1.v b/vlib/crypto/sha1/sha1.v
index e7fbbe6884..b9fd5d8816 100644
--- a/vlib/crypto/sha1/sha1.v
+++ b/vlib/crypto/sha1/sha1.v
@@ -40,8 +40,8 @@ mut:
 }
 
 fn (mut d Digest) reset() {
-	d.x = [byte(0)].repeat(chunk)
-	d.h = [u32(0)].repeat(5)
+	d.x = []byte{len:(chunk)}
+	d.h = []u32{len:(5)}
 	d.h[0] = u32(init0)
 	d.h[1] = u32(init1)
 	d.h[2] = u32(init2)
@@ -105,7 +105,7 @@ pub fn (d &Digest) sum(b_in []byte) []byte {
 fn (mut d Digest) checksum() []byte {
 	mut len := d.len
 	// Padding.  Add a 1 bit and 0 bits until 56 bytes mod 64.
-	mut tmp := [byte(0)].repeat(64)
+	mut tmp := []byte{len:(64)}
 
 	tmp[0] = 0x80
 
@@ -120,7 +120,7 @@ fn (mut d Digest) checksum() []byte {
 	binary.big_endian_put_u64(mut tmp, len)
 	d.write(tmp[..8])
 
-	mut digest := [byte(0)].repeat(size)
+	mut digest := []byte{len:(size)}
 
 	binary.big_endian_put_u32(mut digest, d.h[0])
 	binary.big_endian_put_u32(mut digest[4..], d.h[1])
diff --git a/vlib/crypto/sha1/sha1block_generic.v b/vlib/crypto/sha1/sha1block_generic.v
index 55d7a1f1fe..7928823941 100644
--- a/vlib/crypto/sha1/sha1block_generic.v
+++ b/vlib/crypto/sha1/sha1block_generic.v
@@ -19,7 +19,7 @@ const (
 
 fn block_generic(mut dig Digest, p_ []byte) {
 	mut p := p_
-	mut w := [u32(0)].repeat(16)
+	mut w := []u32{len:(16)}
 	mut h0 := dig.h[0]
 	mut h1 := dig.h[1]
 	mut h2 := dig.h[2]
diff --git a/vlib/crypto/sha256/sha256.v b/vlib/crypto/sha256/sha256.v
index 5aa34ec382..9665517bf9 100644
--- a/vlib/crypto/sha256/sha256.v
+++ b/vlib/crypto/sha256/sha256.v
@@ -52,8 +52,8 @@ mut:
 }
 
 fn (mut d Digest) reset() {
-	d.h = [u32(0)].repeat(8)
-	d.x = [byte(0)].repeat(chunk)
+	d.h = []u32{len:(8)}
+	d.x = []byte{len:(chunk)}
 	if !d.is224 {
 		d.h[0] = u32(init0)
 		d.h[1] = u32(init1)
@@ -144,7 +144,7 @@ fn (d &Digest) sum(b_in []byte) []byte {
 fn (mut d Digest) checksum() []byte {
 	mut len := d.len
 	// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
-	mut tmp := [byte(0)].repeat(64)
+	mut tmp := []byte{len:(64)}
 	tmp[0] = 0x80
 	if int(len)%64 < 56 {
 		d.write(tmp[..56-int(len)%64])
@@ -161,7 +161,7 @@ fn (mut d Digest) checksum() []byte {
 		panic('d.nx != 0')
 	}
 
-	digest := [byte(0)].repeat(size)
+	digest := []byte{len:(size)}
 
 	binary.big_endian_put_u32(mut digest, d.h[0])
 	binary.big_endian_put_u32(mut digest[4..], d.h[1])
@@ -194,7 +194,7 @@ pub fn sum224(data []byte) []byte {
 	mut d := new224()
 	d.write(data)
 	sum := d.checksum()
-	sum224 := [byte(0)].repeat(size224)
+	sum224 := []byte{len:(size224)}
 	copy(sum224, sum[..size224])
 	return sum224
 }
diff --git a/vlib/crypto/sha256/sha256block_generic.v b/vlib/crypto/sha256/sha256block_generic.v
index dafc014364..55e57b40b9 100644
--- a/vlib/crypto/sha256/sha256block_generic.v
+++ b/vlib/crypto/sha256/sha256block_generic.v
@@ -83,7 +83,7 @@ const (
 fn block_generic(mut dig Digest, p_ []byte) {
 	mut p := p_
 
-	mut w := [u32(0)].repeat(64)
+	mut w := []u32{len:(64)}
 
 	mut h0 := dig.h[0]
 	mut h1 := dig.h[1]
diff --git a/vlib/crypto/sha512/sha512.v b/vlib/crypto/sha512/sha512.v
index 3e87dac01d..08538648f7 100644
--- a/vlib/crypto/sha512/sha512.v
+++ b/vlib/crypto/sha512/sha512.v
@@ -70,8 +70,8 @@ mut:
 }
 
 fn (mut d Digest) reset() {
-	d.h = [u64(0)].repeat(8)
-	d.x = [byte(0)].repeat(chunk)
+	d.h = []u64{len:(8)}
+	d.x = []byte{len:(chunk)}
 	match d.function {
 		.sha384 {
 			d.h[0] = init0_384
@@ -212,7 +212,7 @@ fn (d &Digest) sum(b_in []byte) []byte {
 fn (mut d Digest) checksum() []byte {
 	// Padding. Add a 1 bit and 0 bits until 112 bytes mod 128.
 	mut len := d.len
-	mut tmp := [byte(0)].repeat(128)
+	mut tmp := []byte{len:(128)}
 	tmp[0] = 0x80
 	if int(len) % 128 < 112 {
 		d.write(tmp[..112 - int(len) % 128])
@@ -228,7 +228,7 @@ fn (mut d Digest) checksum() []byte {
 	if d.nx != 0 {
 		panic('d.nx != 0')
 	}
-	mut digest := [byte(0)].repeat(size)
+	mut digest := []byte{len:(size)}
 	binary.big_endian_put_u64(mut digest, d.h[0])
 	binary.big_endian_put_u64(mut digest[8..], d.h[1])
 	binary.big_endian_put_u64(mut digest[16..], d.h[2])
@@ -254,7 +254,7 @@ pub fn sum384(data []byte) []byte {
 	mut d := new_digest(.sha384)
 	d.write(data)
 	sum := d.checksum()
-	sum384 := [byte(0)].repeat(size384)
+	sum384 := []byte{len:(size384)}
 	copy(sum384, sum[..size384])
 	return sum384
 }
@@ -264,7 +264,7 @@ pub fn sum512_224(data []byte) []byte {
 	mut d := new_digest(.sha512_224)
 	d.write(data)
 	sum := d.checksum()
-	sum224 := [byte(0)].repeat(size224)
+	sum224 := []byte{len:(size224)}
 	copy(sum224, sum[..size224])
 	return sum224
 }
@@ -274,7 +274,7 @@ pub fn sum512_256(data []byte) []byte {
 	mut d := new_digest(.sha512_256)
 	d.write(data)
 	sum := d.checksum()
-	sum256 := [byte(0)].repeat(size256)
+	sum256 := []byte{len:(size256)}
 	copy(sum256, sum[..size256])
 	return sum256
 }
diff --git a/vlib/crypto/sha512/sha512block_generic.v b/vlib/crypto/sha512/sha512block_generic.v
index 9b90960ddf..3f1f4818d5 100644
--- a/vlib/crypto/sha512/sha512block_generic.v
+++ b/vlib/crypto/sha512/sha512block_generic.v
@@ -95,7 +95,7 @@ const (
 
 fn block_generic(mut dig Digest, p_ []byte) {
 	mut p := p_
-	mut w := [u64(0)].repeat(80)
+	mut w := []u64{len:(80)}
 	mut h0 := dig.h[0]
 	mut h1 := dig.h[1]
 	mut h2 := dig.h[2]
diff --git a/vlib/net/urllib/urllib.v b/vlib/net/urllib/urllib.v
index a53593ab9b..05dd1cb825 100644
--- a/vlib/net/urllib/urllib.v
+++ b/vlib/net/urllib/urllib.v
@@ -256,14 +256,14 @@ fn escape(s string, mode EncodingMode) string {
 	if space_count == 0 && hex_count == 0 {
 		return s
 	}
-	buf := [byte(0)].repeat(64)
+	buf := []byte{len:(64)}
 	mut t := []byte{}
 	required := s.len + 2 * hex_count
 	if required <= buf.len {
 		t = buf[..required]
 	}
 	else {
-		t = [byte(0)].repeat(required)
+		t = []byte{len:(required)}
 	}
 	if hex_count == 0 {
 		copy(t, s.bytes())
diff --git a/vlib/rand/mt19937/mt19937_test.v b/vlib/rand/mt19937/mt19937_test.v
index e9811f10d3..22076bb648 100644
--- a/vlib/rand/mt19937/mt19937_test.v
+++ b/vlib/rand/mt19937/mt19937_test.v
@@ -26,7 +26,7 @@ fn mt19937_basic_test() {
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := [u64(0)].repeat(20)
+	mut randoms := []u64{len:(20)}
 	mut rnd := mt19937.MT19937RNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
diff --git a/vlib/rand/musl/musl_rng_test.v b/vlib/rand/musl/musl_rng_test.v
index 0bcd2c4302..190eb20358 100644
--- a/vlib/rand/musl/musl_rng_test.v
+++ b/vlib/rand/musl/musl_rng_test.v
@@ -16,7 +16,7 @@ const (
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := [u64(0)].repeat(20)
+	mut randoms := []u64{len:(20)}
 	mut rnd := musl.MuslRNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
diff --git a/vlib/rand/splitmix64/splitmix64_test.v b/vlib/rand/splitmix64/splitmix64_test.v
index bfd2895b5d..f75564b256 100644
--- a/vlib/rand/splitmix64/splitmix64_test.v
+++ b/vlib/rand/splitmix64/splitmix64_test.v
@@ -16,7 +16,7 @@ const (
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := [u64(0)].repeat(20)
+	mut randoms := []u64{len:(20)}
 	mut rnd := splitmix64.SplitMix64RNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
diff --git a/vlib/rand/wyrand/wyrand_test.v b/vlib/rand/wyrand/wyrand_test.v
index 42ee859e62..d36190f8d7 100644
--- a/vlib/rand/wyrand/wyrand_test.v
+++ b/vlib/rand/wyrand/wyrand_test.v
@@ -16,7 +16,7 @@ const (
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := [u64(0)].repeat(20)
+	mut randoms := []u64{len:(20)}
 	mut rnd := wyrand.WyRandRNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
diff --git a/vlib/regex/regex.v b/vlib/regex/regex.v
index 426334bf9e..b4422386a5 100644
--- a/vlib/regex/regex.v
+++ b/vlib/regex/regex.v
@@ -479,7 +479,7 @@ enum CharClass_parse_state {
 }
 
 fn (re RE) get_char_class(pc int) string {
-	buf := [byte(0)].repeat(re.cc.len)
+	buf := []byte{len:(re.cc.len)}
 	mut buf_ptr := &byte(&buf)
 
 	mut cc_i := re.prog[pc].cc_index
diff --git a/vlib/strconv/ftoa/f32_str.v b/vlib/strconv/ftoa/f32_str.v
index d3836cd231..55ee20bf49 100644
--- a/vlib/strconv/ftoa/f32_str.v
+++ b/vlib/strconv/ftoa/f32_str.v
@@ -77,7 +77,7 @@ fn (d Dec32) get_string_32(neg bool, i_n_digit int, i_pad_digit int) string {
 		fw_zeros = pad_digit -out_len
 	}
 
-	mut buf := [byte(0)].repeat(out_len + 5 + 1 +1) // sign + mant_len + . +  e + e_sign + exp_len(2) + \0
+	mut buf := []byte{len:int(out_len + 5 + 1 +1)} // sign + mant_len + . +  e + e_sign + exp_len(2) + \0}
 	mut i := 0
 
 	if neg {
diff --git a/vlib/strconv/ftoa/f64_str.v b/vlib/strconv/ftoa/f64_str.v
index 5655addf15..0b110ea03e 100644
--- a/vlib/strconv/ftoa/f64_str.v
+++ b/vlib/strconv/ftoa/f64_str.v
@@ -90,7 +90,7 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
 		fw_zeros = pad_digit - out_len
 	}
 
-	mut buf := [byte(0)].repeat(out_len + 6 + 1 +1 + fw_zeros) // sign + mant_len + . +  e + e_sign + exp_len(2) + \0
+	mut buf := []byte{len:(out_len + 6 + 1 +1 + fw_zeros)} // sign + mant_len + . +  e + e_sign + exp_len(2) + \0}
 	mut i := 0
 
 	if neg {
diff --git a/vlib/sync/pool.v b/vlib/sync/pool.v
index ab63474302..90ec0db8d6 100644
--- a/vlib/sync/pool.v
+++ b/vlib/sync/pool.v
@@ -114,8 +114,8 @@ pub fn (mut pool PoolProcessor) work_on_pointers(items []voidptr) {
 	pool.results = []
 	pool.thread_contexts = []
 	pool.items << items
-	pool.results = [voidptr(0)].repeat(pool.items.len)
-	pool.thread_contexts << [voidptr(0)].repeat(pool.items.len)
+	pool.results = []voidptr{len:(pool.items.len)}
+	pool.thread_contexts << []voidptr{len:(pool.items.len)}
 	pool.waitgroup.add(njobs)
 	for i := 0; i < njobs; i++ {
 		if njobs > 1 {
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index 3235f2e0fc..3e103f36b9 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -841,9 +841,9 @@ fn (mut g Gen) for_in(it ast.ForInStmt) {
 			g.writeln(', $key, &($val_styp[]){ $zero }));')
 		}
 		g.stmts(it.stmts)
-		g.writeln('/* for in map cleanup*/ string_free(&$key);')
 		g.writeln('}')
 		g.writeln('/*for in map cleanup*/')
+		g.writeln('for (int $idx = 0; $idx < ${keys_tmp}.len; $idx++) { string_free(&(($key_styp*)${keys_tmp}.data)[$idx]); }')
 		g.writeln('array_free(&$keys_tmp);')
 	} else if it.cond_type.has_flag(.variadic) {
 		g.writeln('// FOR IN cond_type/variadic')
diff --git a/vlib/v/gen/tests/3.vv b/vlib/v/gen/tests/3.vv
index 4c4403145d..15c2bf1a98 100644
--- a/vlib/v/gen/tests/3.vv
+++ b/vlib/v/gen/tests/3.vv
@@ -25,7 +25,7 @@ fn get_user_opt() ?User {
 
 fn (u &User) foo() {
 	age := u.age
-	zzz := [''].repeat(u.age)
+	zzz := []string{len:(u.age)}
 	a := 10
 	if a in [10, 20, 30] {
 		b := 10
diff --git a/vlib/v/token/token.v b/vlib/v/token/token.v
index 37689f65e1..ff7a57906c 100644
--- a/vlib/v/token/token.v
+++ b/vlib/v/token/token.v
@@ -148,7 +148,7 @@ fn build_keys() map[string]Kind {
 
 // TODO remove once we have `enum Kind { name('name') if('if') ... }`
 fn build_token_str() []string {
-	mut s := [''].repeat(nr_tokens)
+	mut s := []string{len:(nr_tokens)}
 	s[Kind.unknown] = 'unknown'
 	s[Kind.eof] = 'eof'
 	s[Kind.name] = 'name'