diff --git a/cmd/tools/modules/testing/common.v b/cmd/tools/modules/testing/common.v
index 1398663f71..ef4ebf2956 100644
--- a/cmd/tools/modules/testing/common.v
+++ b/cmd/tools/modules/testing/common.v
@@ -50,7 +50,7 @@ pub fn new_test_session(_vargs string) TestSession {
 		skip_files: skip_files
 		vargs: vargs
 		show_ok_tests: !_vargs.contains('-silent')
-		message_handler: 0
+		message_handler: &TestMessageHandler(0)
 	}
 }
 
diff --git a/doc/docs.md b/doc/docs.md
index 7980f8cb6d..6e03f1fdc5 100644
--- a/doc/docs.md
+++ b/doc/docs.md
@@ -269,6 +269,8 @@ rune // represents a Unicode code point
 
 f32 f64
 
+any_int, any_float // internal intermediate types of number literals
+
 byteptr // these two are mostly used for C interop
 voidptr
 
@@ -277,6 +279,27 @@ any // similar to C's void* and Go's interface{}
 
 Please note that unlike C and Go, `int` is always a 32 bit integer.
 
+There is an exceptions to the rule that all operators
+in V must have values of the same type on both sides. A small primitive type
+on one side can be automatically promoted if it fits
+completely into the data range of the type on the other side, i.e. when
+the promotion does not result in any data loss.
+These are the allowed possibilities:
+
+```
+   i8 → i16 → int → i64
+            ↘     ↘
+              f32 → f64
+            ↗     ↗
+ byte → u16 → u32 → u64 ⬎
+      ↘     ↘     ↘      ptr
+   i8 → i16 → int → i64 ⬏
+```
+An `int` value for example can be automatically promoted to `f64`
+or `i64` but not to `f32` or `u32`. (`f32` would mean precission
+loss for large values and `u32` would mean loss of the sign for
+negative values).
+
 ## Strings
 
 ```v
diff --git a/vlib/builtin/array.v b/vlib/builtin/array.v
index 7c300eb68c..2b036f9786 100644
--- a/vlib/builtin/array.v
+++ b/vlib/builtin/array.v
@@ -360,9 +360,9 @@ pub fn (b []byte) hex() string {
 	mut dst_i := 0
 	for i in b {
 		n0 := i >> 4
-		hex[dst_i++] = if n0 < 10 { n0 + `0` } else { n0 + 87 }
+		hex[dst_i++] = if n0 < 10 { n0 + `0` } else { n0 + byte(87) }
 		n1 := i & 0xF
-		hex[dst_i++] = if n1 < 10 { n1 + `0` } else { n1 + 87 }
+		hex[dst_i++] = if n1 < 10 { n1 + `0` } else { n1 + byte(87) }
 	}
 	hex[dst_i] = `\0`
 	return tos(hex,dst_i)
diff --git a/vlib/builtin/array_test.v b/vlib/builtin/array_test.v
index cd7a883a04..7702a93935 100644
--- a/vlib/builtin/array_test.v
+++ b/vlib/builtin/array_test.v
@@ -468,6 +468,10 @@ fn test_in() {
 	assert !(0 in a)
 	assert 0 !in a
 	assert 4 !in a
+	b := [1, 4, 0]
+	c := [3, 6, 2, 0]
+	assert 0 in b
+	assert 0 in c
 }
 
 fn sum(prev int, curr int) int {
@@ -557,7 +561,7 @@ fn test_map() {
 	assert strs.map(it.to_upper()) == ['V', 'IS', 'AWESOME']
 	assert strs.map(it == 'awesome') == [false, false, true]
 	assert strs.map(it.len in nums) == [true, true, false]
-	assert strs.map(7) == [7, 7, 7]
+	assert strs.map(int(7)) == [7, 7, 7]
 
 	// external func
 	assert nums.map(map_test_helper_1(it)) == [1, 4, 9, 16, 25, 36]
@@ -568,9 +572,9 @@ fn test_map() {
 	assert []int{len:0}.map(it * 2) == []
 
 	// nested maps (where it is of same type)
-	assert nums.map( strs.map(7) == [7, 7, 7] ) == [true, true, true, true, true, true]
+	assert nums.map( strs.map(int(7)) == [7, 7, 7] ) == [true, true, true, true, true, true]
 	assert nums.map( '$it' + strs.map('a')[0] ) == ['1a', '2a', '3a', '4a', '5a', '6a']
-	assert nums.map( it + strs.map(7)[0] ) == [8, 9, 10, 11, 12, 13]
+	assert nums.map( it + strs.map(int(7))[0] ) == [8, 9, 10, 11, 12, 13]
 	assert nums.map( it + strs.map(it.len)[0] ) == [2, 3, 4, 5, 6, 7]
 	assert strs.map( it.len + strs.map(it.len)[0] ) == [2, 3, 8]
 
diff --git a/vlib/builtin/float.v b/vlib/builtin/float.v
index b4d84ce58e..dbb2a961d1 100644
--- a/vlib/builtin/float.v
+++ b/vlib/builtin/float.v
@@ -13,6 +13,17 @@ pub fn (d f64) str() string {
 	return ftoa.ftoa_64(d)
 }
 
+[inline]
+pub fn (d any_float) str() string {
+	x := f64(d)
+	abs_x := f64_abs(x)
+	if abs_x >= 0.01 && abs_x < 1.0e16 {
+		return ftoa.f64_to_str_l(x)
+	} else {
+		return ftoa.ftoa_64(x)
+	}
+}
+
 // return a string of the input f64 in scientific notation with digit_num deciamals displayed, max 17 digits
 [inline]
 pub fn (x f64) strsci(digit_num int) string {
@@ -84,7 +95,7 @@ pub fn (a f64) eq(b f64) bool {
 
 [inline]
 pub fn (a f32) eq(b f32) bool {
-	return f32_abs(a - b) <= C.FLT_EPSILON
+	return f32_abs(a - b) <= f32(C.FLT_EPSILON)
 }
 
 pub fn (a f64) eqbit(b f64) bool {
diff --git a/vlib/builtin/int.v b/vlib/builtin/int.v
index 433e94a96a..357e226351 100644
--- a/vlib/builtin/int.v
+++ b/vlib/builtin/int.v
@@ -144,6 +144,11 @@ pub fn (nn u32) str() string {
 	//return tos(buf + index, (max-index))
 }
 
+[inline]
+pub fn (n any_int) str() string {
+	return i64(n).str()
+}
+
 pub fn (nn i64) str() string {
 	mut n := nn
 	mut d := i64(0)
@@ -188,7 +193,7 @@ pub fn (nn i64) str() string {
 
 pub fn (nn u64) str() string {
 	mut n := nn
-	mut d := 0
+	mut d := u64(0)
 	if n == 0 {
 		return '0'
 	}
@@ -274,7 +279,7 @@ pub fn (nn u16) hex() string {
 	mut index := max
 	buf[index--] = `\0`
 	for n > 0 {
-		d := n & 0xF
+		d := byte(n & 0xF)
 		n = n >> 4
 		buf[index--] = if d < 10 { d + `0` } else { d + 87 }
 	}
@@ -301,7 +306,7 @@ pub fn (nn u32) hex() string {
 	mut index := max
 	buf[index--] = `\0`
 	for n > 0 {
-		d := n & 0xF
+		d := byte(n & 0xF)
 		n = n >> 4
 		buf[index--] = if d < 10 { d + `0` } else { d + 87 }
 	}
@@ -328,7 +333,7 @@ pub fn (nn u64) hex() string {
 	mut index := max
 	buf[index--] = `\0`
 	for n > 0 {
-		d := n & 0xF
+		d := byte(n & 0xF)
 		n = n >> 4
 		buf[index--] = if d < 10 { d + `0` } else { d + 87 }
 	}
@@ -345,6 +350,10 @@ pub fn (nn i64) hex() string {
 	return u64(nn).hex()
 }
 
+pub fn (nn any_int) hex() string {
+	return u64(nn).hex()
+}
+
 pub fn (nn voidptr) str() string {
 	return u64(nn).hex()
 }
diff --git a/vlib/builtin/int_test.v b/vlib/builtin/int_test.v
index ff4bc9a2ba..ac9454b640 100644
--- a/vlib/builtin/int_test.v
+++ b/vlib/builtin/int_test.v
@@ -214,7 +214,7 @@ fn test_int_to_hex() {
 	assert u32(c0).hex() == 'c'
 	assert 2147483647.hex() == '7fffffff'
 	assert u32(2147483647).hex() == '7fffffff'
-	assert (-1).hex() == 'ffffffff'
+	assert (-1).hex() == 'ffffffffffffffff'
 	assert u32(4294967295).hex() == 'ffffffff'
 	// 64 bit
 	assert u64(0).hex() == '0'
diff --git a/vlib/builtin/map.v b/vlib/builtin/map.v
index 9b37a43877..9d60e2fad3 100644
--- a/vlib/builtin/map.v
+++ b/vlib/builtin/map.v
@@ -123,22 +123,22 @@ fn (mut d DenseArray) push(key string, value voidptr) u32 {
 	if d.cap == d.size {
 		d.cap += d.cap >> 3
 		d.keys = &string(C.realloc(d.keys, sizeof(string) * d.cap))
-		d.values = C.realloc(d.values, d.value_bytes * d.cap)
+		d.values = C.realloc(d.values, u32(d.value_bytes) * d.cap)
 	}
 	push_index := d.size
 	d.keys[push_index] = key
-	C.memcpy(d.values + push_index * d.value_bytes, value, d.value_bytes)
+	C.memcpy(d.values + push_index * u32(d.value_bytes), value, d.value_bytes)
 	d.size++
 	return push_index
 }
 
 fn (d DenseArray) get(i int) voidptr {
 	$if !no_bounds_checking? {
-		if i < 0 || i >= d.size {
+		if i < 0 || i >= int(d.size) {
 			panic('DenseArray.get: index out of range (i == $i, d.len == $d.size)')
 		}
 	}
-	return byteptr(d.keys) + i * sizeof(string)
+	return byteptr(d.keys) + i * int(sizeof(string))
 }
 
 // Move all zeros to the end of the array
@@ -153,8 +153,8 @@ fn (mut d DenseArray) zeros_to_end() {
 			d.keys[count] = d.keys[i]
 			d.keys[i] = tmp_key
 			// swap values (TODO: optimize)
-			C.memcpy(tmp_value, d.values + count * d.value_bytes, d.value_bytes)
-			C.memcpy(d.values + count * d.value_bytes, d.values + i * d.value_bytes, d.value_bytes)
+			C.memcpy(tmp_value, d.values + count * u32(d.value_bytes), d.value_bytes)
+			C.memcpy(d.values + count * u32(d.value_bytes), d.values + i * d.value_bytes, d.value_bytes)
 			C.memcpy(d.values + i * d.value_bytes, tmp_value, d.value_bytes)
 			count++
 		}
@@ -164,7 +164,7 @@ fn (mut d DenseArray) zeros_to_end() {
 	d.size = count
 	d.cap = if count < 8 { u32(8) } else { count }
 	d.keys = &string(C.realloc(d.keys, sizeof(string) * d.cap))
-	d.values = C.realloc(d.values, d.value_bytes * d.cap)
+	d.values = C.realloc(d.values, u32(d.value_bytes) * d.cap)
 }
 
 pub struct map {
@@ -280,7 +280,7 @@ fn (mut m map) set(k string, value voidptr) {
 	for meta == m.metas[index] {
 		kv_index := m.metas[index + 1]
 		if fast_string_eq(key, m.key_values.keys[kv_index]) {
-			C.memcpy(m.key_values.values + kv_index * m.value_bytes , value, m.value_bytes)
+			C.memcpy(m.key_values.values + kv_index * u32(m.value_bytes), value, m.value_bytes)
 			return
 		}
 		index += 2
@@ -349,7 +349,7 @@ fn (m map) get3(key string, zero voidptr) voidptr {
 		if meta == m.metas[index] {
 			kv_index := m.metas[index + 1]
 			if fast_string_eq(key, m.key_values.keys[kv_index]) {
-				return voidptr(m.key_values.values + kv_index * m.value_bytes)
+				return voidptr(m.key_values.values + kv_index * u32(m.value_bytes))
 			}
 		}
 		index += 2
@@ -431,10 +431,10 @@ pub fn (d DenseArray) clone() DenseArray {
 		size:        d.size
 		deletes:     d.deletes
 		keys:        &string(malloc(d.cap * sizeof(string)))
-		values:      byteptr(malloc(d.cap * d.value_bytes))
+		values:      byteptr(malloc(d.cap * u32(d.value_bytes)))
 	}
 	C.memcpy(res.keys, d.keys, d.cap * sizeof(string))
-	C.memcpy(res.values, d.values, d.cap * d.value_bytes)
+	C.memcpy(res.values, d.values, d.cap * u32(d.value_bytes))
 	return res
 }
 
diff --git a/vlib/builtin/string.v b/vlib/builtin/string.v
index 5e95ef3c50..65af029ca6 100644
--- a/vlib/builtin/string.v
+++ b/vlib/builtin/string.v
@@ -750,7 +750,7 @@ pub fn (s string) ends_with(p string) bool {
 pub fn (s string) to_lower() string {
 	mut b := malloc(s.len + 1)
 	for i in 0..s.len {
-		b[i] = C.tolower(s.str[i])
+		b[i] = byte(C.tolower(s.str[i]))
 	}
 	return tos(b, s.len)
 }
@@ -767,7 +767,7 @@ pub fn (s string) is_lower() bool {
 pub fn (s string) to_upper() string {
 	mut b := malloc(s.len + 1)
 	for i in 0..s.len {
-		b[i] = C.toupper(s.str[i])
+		b[i] = byte(C.toupper(s.str[i]))
 	}
 	return tos(b, s.len)
 }
diff --git a/vlib/builtin/utf8.v b/vlib/builtin/utf8.v
index 28905f1073..8273620f68 100644
--- a/vlib/builtin/utf8.v
+++ b/vlib/builtin/utf8.v
@@ -13,33 +13,33 @@ pub fn utf32_to_str(code u32) string {
 	icode := int(code) // Prevents doing casts everywhere
 	mut buffer := malloc(5)
 	if icode <= 127/* 0x7F */ {
-		buffer[0] = icode
+		buffer[0] = byte(icode)
 		return tos(buffer, 1)
 	}
 	if icode <= 2047/* 0x7FF */ {
-		buffer[0] = 192/*0xC0*/ | (icode>>6)/* 110xxxxx */
+		buffer[0] = 192/*0xC0*/ | byte(icode>>6)/* 110xxxxx */
 
-		buffer[1] = 128/*0x80*/ | (icode & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[1] = 128/*0x80*/ | byte(icode & 63/*0x3F*/)/* 10xxxxxx */
 
 		return tos(buffer, 2)
 	}
 	if icode <= 65535/* 0xFFFF */ {
-		buffer[0] = 224/*0xE0*/ | (icode>>12)/* 1110xxxx */
+		buffer[0] = 224/*0xE0*/ | byte(icode>>12)/* 1110xxxx */
 
-		buffer[1] = 128/*0x80*/ | ((icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[1] = 128/*0x80*/ | (byte(icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
 
-		buffer[2] = 128/*0x80*/ | (icode & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[2] = 128/*0x80*/ | byte(icode & 63/*0x3F*/)/* 10xxxxxx */
 
 		return tos(buffer, 3)
 	}
 	if icode <= 1114111/* 0x10FFFF */ {
-		buffer[0] = 240/*0xF0*/ | (icode>>18)/* 11110xxx */
+		buffer[0] = 240/*0xF0*/ | byte(icode>>18)/* 11110xxx */
 
-		buffer[1] = 128/*0x80*/ | ((icode>>12) & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[1] = 128/*0x80*/ | (byte(icode>>12) & 63/*0x3F*/)/* 10xxxxxx */
 
-		buffer[2] = 128/*0x80*/ | ((icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[2] = 128/*0x80*/ | (byte(icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
 
-		buffer[3] = 128/*0x80*/ | (icode & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[3] = 128/*0x80*/ | byte(icode & 63/*0x3F*/)/* 10xxxxxx */
 
 		return tos(buffer, 4)
 	}
@@ -51,33 +51,33 @@ pub fn utf32_to_str_no_malloc(code u32, buf voidptr) string {
 	icode := int(code) // Prevents doing casts everywhere
 	mut buffer := byteptr(buf)
 	if icode <= 127/* 0x7F */ {
-		buffer[0] = icode
+		buffer[0] = byte(icode)
 		return tos(buffer, 1)
 	}
 	if icode <= 2047/* 0x7FF */ {
-		buffer[0] = 192/*0xC0*/ | (icode>>6)/* 110xxxxx */
+		buffer[0] = 192/*0xC0*/ | byte(icode>>6)/* 110xxxxx */
 
-		buffer[1] = 128/*0x80*/ | (icode & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[1] = 128/*0x80*/ | byte(icode & 63/*0x3F*/)/* 10xxxxxx */
 
 		return tos(buffer, 2)
 	}
 	if icode <= 65535/* 0xFFFF */ {
-		buffer[0] = 224/*0xE0*/ | (icode>>12)/* 1110xxxx */
+		buffer[0] = 224/*0xE0*/ | byte(icode>>12)/* 1110xxxx */
 
-		buffer[1] = 128/*0x80*/ | ((icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[1] = 128/*0x80*/ | (byte(icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
 
-		buffer[2] = 128/*0x80*/ | (icode & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[2] = 128/*0x80*/ | byte(icode & 63/*0x3F*/)/* 10xxxxxx */
 
 		return tos(buffer, 3)
 	}
 	if icode <= 1114111/* 0x10FFFF */ {
-		buffer[0] = 240/*0xF0*/ | (icode>>18)/* 11110xxx */
+		buffer[0] = 240/*0xF0*/ | byte(icode>>18)/* 11110xxx */
 
-		buffer[1] = 128/*0x80*/ | ((icode>>12) & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[1] = 128/*0x80*/ | (byte(icode>>12) & 63/*0x3F*/)/* 10xxxxxx */
 
-		buffer[2] = 128/*0x80*/ | ((icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[2] = 128/*0x80*/ | (byte(icode>>6) & 63/*0x3F*/)/* 10xxxxxx */
 
-		buffer[3] = 128/*0x80*/ | (icode & 63/*0x3F*/)/* 10xxxxxx */
+		buffer[3] = 128/*0x80*/ | byte(icode & 63/*0x3F*/)/* 10xxxxxx */
 
 		return tos(buffer, 4)
 	}
diff --git a/vlib/clipboard/clipboard_windows.c.v b/vlib/clipboard/clipboard_windows.c.v
index 072f5e649d..9eecbee97e 100644
--- a/vlib/clipboard/clipboard_windows.c.v
+++ b/vlib/clipboard/clipboard_windows.c.v
@@ -127,7 +127,7 @@ fn (mut cb Clipboard) free() {
 fn to_wide(text string) &C.HGLOBAL {
 	len_required := C.MultiByteToWideChar(C.CP_UTF8, C.MB_ERR_INVALID_CHARS, text.str, text.len +
 		1, C.NULL, 0)
-    buf := C.GlobalAlloc(C.GMEM_MOVEABLE, sizeof(u16) * len_required)
+    buf := C.GlobalAlloc(C.GMEM_MOVEABLE, i64(sizeof(u16)) * len_required)
     if buf != C.HGLOBAL(C.NULL) {
         mut locked := &u16(C.GlobalLock(buf))
         C.MultiByteToWideChar(C.CP_UTF8, C.MB_ERR_INVALID_CHARS, text.str, text.len + 1, locked, len_required)
diff --git a/vlib/freetype/freetype.v b/vlib/freetype/freetype.v
index f3113a7cd3..42e53fbee2 100644
--- a/vlib/freetype/freetype.v
+++ b/vlib/freetype/freetype.v
@@ -152,8 +152,8 @@ fn ft_load_char(face &C.FT_FaceRec, code i64) Character {
 		horizontal_bearing_px:  gg.vec2((*face).glyph.metrics.horiBearingX >> 6, (*face).glyph.metrics.horiBearingY >> 6)
 		vertical_bearing_px:    gg.vec2((*face).glyph.metrics.vertBearingX >> 6, (*face).glyph.metrics.vertBearingY >> 6) // not used for now
 
-		horizontal_advance_px:  (*face).glyph.metrics.horiAdvance >> 6
-		vertical_advance_px:    (*face).glyph.metrics.vertAdvance >> 6
+		horizontal_advance_px:  u32((*face).glyph.metrics.horiAdvance) >> 6
+		vertical_advance_px:    u32((*face).glyph.metrics.vertAdvance) >> 6
 	}
 }
 
@@ -203,7 +203,7 @@ pub fn new_context(cfg gg.Cfg) &FreeType {
 	}
 	if !os.exists(font_path) {
 		eprintln('freetype: font "$font_path" does not exist')
-		return 0
+		return voidptr(0)
 	}
 	face := &C.FT_FaceRec{
 		glyph: 0
@@ -289,11 +289,11 @@ fn (mut ctx FreeType) private_draw_text(_x, _y int, utext ustring, cfg gx.TextCf
 	if cfg.align == gx.align_right {
 		// width := utext.len * 7
 		width := wx
-		x -= width + 10
+		x -= f32(width + 10)
 	}
-	x *= ctx.scale
-	y *= ctx.scale
-	y += yoffset
+	x *= f32(ctx.scale)
+	y *= f32(ctx.scale)
+	y += f32(yoffset)
 	y = f32(ctx.height) - y // invert y direction
 	color := cfg.color
 	// Activate corresponding render state
diff --git a/vlib/gg/utils.v b/vlib/gg/utils.v
index a84faf0854..7075d8dfd7 100644
--- a/vlib/gg/utils.v
+++ b/vlib/gg/utils.v
@@ -8,7 +8,7 @@ fn arc_vertices(x, y, r, start_angle, end_angle f32, segments int) []f32 {
 	mut vertices := []f32{}
 	start_rads := start_angle * 0.0174533 // deg -> rad approx
 	end_rads := end_angle * 0.0174533
-	increment := (end_rads - start_rads) / segments
+	increment := (end_rads - start_rads) / f32(segments)
 	vertices << [x + f32(math.cos(start_rads)) * r, y + f32(math.sin(start_rads)) * r] !
 	mut i := 1
 	for i < segments {
diff --git a/vlib/gl/gl.v b/vlib/gl/gl.v
index c9ba9fe3d8..e2ca96f988 100644
--- a/vlib/gl/gl.v
+++ b/vlib/gl/gl.v
@@ -183,12 +183,12 @@ pub fn buffer_data(typ, size int, arr voidptr, draw_typ int) {
 }
 
 pub fn buffer_data_int(typ int, vertices []int, draw_typ int) {
-	size := sizeof(int) * vertices.len
+	size := sizeof(int) * u32(vertices.len)
 	C.glBufferData(typ, size, vertices.data, draw_typ)
 }
 
 pub fn buffer_data_f32(typ int, vertices []f32, draw_typ int) {
-	size := sizeof(f32) * vertices.len
+	size := sizeof(f32) * u32(vertices.len)
 	C.glBufferData(typ, size, vertices.data, draw_typ)
 }
 
@@ -263,11 +263,11 @@ pub fn gen_buffer() u32 {
 }
 
 pub fn vertex_attrib_pointer(index, size int, typ int, normalized bool, _stride int, _ptr int) {
-	mut stride := _stride
+	mut stride := u32(_stride)
 	mut ptr := _ptr
 	if typ == C.GL_FLOAT {
 		stride *= sizeof(f32)
-		ptr *= sizeof(f32)
+		ptr *= int(sizeof(f32))
 	}
 	C.glVertexAttribPointer(index, size, typ, normalized, stride, ptr)
 }
@@ -311,4 +311,4 @@ pub fn set_bool(loc int, val bool) {
 	} else {
 		set_f32(loc, 0)
 	}
-}
\ No newline at end of file
+}
diff --git a/vlib/net/websocket/ws.v b/vlib/net/websocket/ws.v
index ee3118fc32..1de9384d08 100644
--- a/vlib/net/websocket/ws.v
+++ b/vlib/net/websocket/ws.v
@@ -191,8 +191,8 @@ pub fn (mut ws Client) close(code int, message string) {
 			code_ := C.htons(code)
 			message_len := message.len + 2
 			mut close_frame := [`0`].repeat(message_len)
-			close_frame[0] = code_ & 0xFF
-			close_frame[1] = (code_ >> 8)
+			close_frame[0] = byte(code_ & 0xFF)
+			close_frame[1] = byte(code_ >> 8)
 			code32 = (close_frame[0] << 8) + close_frame[1]
 			for i in 0 .. message.len {
 				close_frame[i + 2] = message[i]
@@ -248,9 +248,9 @@ pub fn (mut ws Client) write(payload byteptr, payload_len int, code OPCode) int
 	fbdata := byteptr( frame_buf.data )
 	masking_key := create_masking_key()
 	mut header := [`0`].repeat(header_len)
-	header[0] = (int(code) | 0x80)
+	header[0] = byte(code) | 0x80
 	if payload_len <= 125 {
-		header[1] = (payload_len | 0x80)
+		header[1] = byte(payload_len | 0x80)
 		header[2] = masking_key[0]
 		header[3] = masking_key[1]
 		header[4] = masking_key[2]
@@ -417,7 +417,7 @@ pub fn (mut ws Client) read() int {
 	} else if frame.opcode in [.text_frame, .binary_frame] {
 		data_node:
 		l.d('read: recieved text_frame or binary_frame')
-		mut payload := malloc(sizeof(byte) * int(payload_len) + 1)
+		mut payload := malloc(sizeof(byte) * u32(payload_len) + 1)
 		if payload == 0 {
 			l.f('out of memory')
 		}
@@ -437,7 +437,7 @@ pub fn (mut ws Client) read() int {
 						size += f.len
 					}
 				}
-				mut pl := malloc(sizeof(byte) * int(size))
+				mut pl := malloc(sizeof(byte) * u32(size))
 				if pl == 0 {
 					l.f('out of memory')
 				}
@@ -581,8 +581,8 @@ fn (mut ws Client) send_control_frame(code OPCode, frame_typ string, payload []b
 	frame_len := header_len + payload.len
 	mut control_frame := [`0`].repeat(frame_len)
 	masking_key := create_masking_key()
-	control_frame[0] = (int(code) | 0x80)
-	control_frame[1] = (payload.len | 0x80)
+	control_frame[0] = byte(code | 0x80)
+	control_frame[1] = byte(payload.len | 0x80)
 	control_frame[2] = masking_key[0]
 	control_frame[3] = masking_key[1]
 	control_frame[4] = masking_key[2]
diff --git a/vlib/os/environment.v b/vlib/os/environment.v
index 16863a732e..130c733398 100644
--- a/vlib/os/environment.v
+++ b/vlib/os/environment.v
@@ -19,7 +19,7 @@ pub fn getenv(key string) string {
 		return string_from_wide(s)
 	} $else {
 		s := C.getenv(key.str)
-		if s == 0 {
+		if s == voidptr(0) {
 			return ''
 		}
 		// NB: C.getenv *requires* that the result be copied.
diff --git a/vlib/os/inode.v b/vlib/os/inode.v
index 4c25eb13b7..a08b2e6a9d 100644
--- a/vlib/os/inode.v
+++ b/vlib/os/inode.v
@@ -35,19 +35,19 @@ pub fn inode(path string) FileMode {
 	C.stat(path.str, &attr)
 
 	mut typ := FileType.regular
-	if attr.st_mode & C.S_IFMT == C.S_IFDIR {
+	if attr.st_mode & u32(C.S_IFMT) == u32(C.S_IFDIR) {
 		typ = .directory
 	}
 	$if !windows {
-		if attr.st_mode & C.S_IFMT == C.S_IFCHR {
+		if attr.st_mode & u32(C.S_IFMT) == u32(C.S_IFCHR) {
 			typ = .character_device
-		} else if attr.st_mode & C.S_IFMT == C.S_IFBLK {
+		} else if attr.st_mode & u32(C.S_IFMT) == u32(C.S_IFBLK) {
 			typ = .block_device
-		} else if attr.st_mode & C.S_IFMT == C.S_IFIFO {
+		} else if attr.st_mode & u32(C.S_IFMT) == u32(C.S_IFIFO) {
 			typ = .fifo
-		} else if attr.st_mode & C.S_IFMT == C.S_IFLNK {
+		} else if attr.st_mode & u32(C.S_IFMT) == u32(C.S_IFLNK) {
 			typ = .symbolic_link
-		} else if attr.st_mode & C.S_IFMT == C.S_IFSOCK {
+		} else if attr.st_mode & u32(C.S_IFMT) == u32(C.S_IFSOCK) {
 			typ = .socket
 		}
 	}
@@ -56,38 +56,38 @@ pub fn inode(path string) FileMode {
 		return FileMode{
 			typ: typ
 			owner: FilePermission{
-				read: bool(attr.st_mode & C.S_IREAD)
-				write: bool(attr.st_mode & C.S_IWRITE)
-				execute: bool(attr.st_mode & C.S_IEXEC)
+				read: bool(attr.st_mode & u32(C.S_IREAD))
+				write: bool(attr.st_mode & u32(C.S_IWRITE))
+				execute: bool(attr.st_mode & u32(C.S_IEXEC))
 			}
 			group: FilePermission{
-				read: bool(attr.st_mode & C.S_IREAD)
-				write: bool(attr.st_mode & C.S_IWRITE)
-				execute: bool(attr.st_mode & C.S_IEXEC)
+				read: bool(attr.st_mode & u32(C.S_IREAD))
+				write: bool(attr.st_mode & u32(C.S_IWRITE))
+				execute: bool(attr.st_mode & u32(C.S_IEXEC))
 			}
 			others: FilePermission{
-				read: bool(attr.st_mode & C.S_IREAD)
-				write: bool(attr.st_mode & C.S_IWRITE)
-				execute: bool(attr.st_mode & C.S_IEXEC)
+				read: bool(attr.st_mode & u32(C.S_IREAD))
+				write: bool(attr.st_mode & u32(C.S_IWRITE))
+				execute: bool(attr.st_mode & u32(C.S_IEXEC))
 			}
 		}
 	} $else {
 		return FileMode{
 			typ: typ
 			owner: FilePermission{
-				read: bool(attr.st_mode & C.S_IRUSR)
-				write: bool(attr.st_mode & C.S_IWUSR)
-				execute: bool(attr.st_mode & C.S_IXUSR)
+				read: bool(attr.st_mode & u32(C.S_IRUSR))
+				write: bool(attr.st_mode & u32(C.S_IWUSR))
+				execute: bool(attr.st_mode & u32(C.S_IXUSR))
 			}
 			group: FilePermission{
-				read: bool(attr.st_mode & C.S_IRGRP)
-				write: bool(attr.st_mode & C.S_IWGRP)
-				execute: bool(attr.st_mode & C.S_IXGRP)
+				read: bool(attr.st_mode & u32(C.S_IRGRP))
+				write: bool(attr.st_mode & u32(C.S_IWGRP))
+				execute: bool(attr.st_mode & u32(C.S_IXGRP))
 			}
 			others: FilePermission{
-				read: bool(attr.st_mode & C.S_IROTH)
-				write: bool(attr.st_mode & C.S_IWOTH)
-				execute: bool(attr.st_mode & C.S_IXOTH)
+				read: bool(attr.st_mode & u32(C.S_IROTH))
+				write: bool(attr.st_mode & u32(C.S_IWOTH))
+				execute: bool(attr.st_mode & u32(C.S_IXOTH))
 			}
 		}
 	}
diff --git a/vlib/os/os.v b/vlib/os/os.v
index d9eedb766d..f46fc8a589 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -1090,12 +1090,12 @@ pub fn real_path(fpath string) string {
 	mut fullpath := vcalloc(max_path_len)
 	mut ret := charptr(0)
 	$if windows {
-		ret = C._fullpath(fullpath, fpath.str, max_path_len)
+		ret = charptr(C._fullpath(fullpath, fpath.str, max_path_len))
 		if ret == 0 {
 			return fpath
 		}
 	} $else {
-		ret = C.realpath(fpath.str, fullpath)
+		ret = charptr(C.realpath(fpath.str, fullpath))
 		if ret == 0 {
 			return fpath
 		}
@@ -1324,7 +1324,7 @@ pub fn open(path string) ?File {
 	}
   */
 	cfile := vfopen(path, 'rb')
-	if cfile == 0 {
+	if cfile == voidptr(0) {
 		return error('failed to open file "$path"')
 	}
 	fd := fileno(cfile)
@@ -1361,7 +1361,7 @@ pub fn create(path string) ?File {
 	}
   */
 	cfile := vfopen(path, 'wb')
-	if cfile == 0 {
+	if cfile == voidptr(0) {
 		return error('failed to create file "$path"')
 	}
 	fd := fileno(cfile)
diff --git a/vlib/os/os_windows.c.v b/vlib/os/os_windows.c.v
index 228b61ed85..c290df8ffc 100644
--- a/vlib/os/os_windows.c.v
+++ b/vlib/os/os_windows.c.v
@@ -146,7 +146,7 @@ pub fn mkdir(path string) ?bool {
 // get_file_handle retrieves the operating-system file handle that is associated with the specified file descriptor.
 pub fn get_file_handle(path string) HANDLE {
     cfile := vfopen(path, 'rb')
-    if cfile == 0 {
+    if cfile == voidptr(0) {
 	    return HANDLE(invalid_handle_value)
     }
     handle := HANDLE(C._get_osfhandle(fileno(cfile))) // CreateFile? - hah, no -_-
diff --git a/vlib/strconv/ftoa/f32_str.v b/vlib/strconv/ftoa/f32_str.v
index 7a09bf525f..64dda843e5 100644
--- a/vlib/strconv/ftoa/f32_str.v
+++ b/vlib/strconv/ftoa/f32_str.v
@@ -59,7 +59,7 @@ const(
 const(
 	mantbits32  = u32(23)
 	expbits32   = u32(8)
-	bias32      = u32(127) // f32 exponent bias
+	bias32      = 127 // f32 exponent bias
 	maxexp32    = 255
 )
 
@@ -189,10 +189,10 @@ pub fn f32_to_decimal(mant u32, exp u32) Dec32 {
 	if exp == 0 {
 		// We subtract 2 so that the bounds computation has
 		// 2 additional bits.
-		e2 = 1 - bias32 - mantbits32 - 2
+		e2 = 1 - bias32 - int(mantbits32) - 2
 		m2 = mant
 	} else {
-		e2 = int(exp) - bias32 - mantbits32 - 2
+		e2 = int(exp) - bias32 - int(mantbits32) - 2
 		m2 = (u32(1) << mantbits32) | mant
 	}
 	even          := (m2 & 1) == 0
diff --git a/vlib/strconv/ftoa/f64_str.v b/vlib/strconv/ftoa/f64_str.v
index 68e63044c4..530bb579df 100644
--- a/vlib/strconv/ftoa/f64_str.v
+++ b/vlib/strconv/ftoa/f64_str.v
@@ -73,7 +73,7 @@ const(
 const(
 	mantbits64  = u32(52)
 	expbits64   = u32(11)
-	bias64      = u32(1023) // f64 exponent bias
+	bias64      = 1023 // f64 exponent bias
 	maxexp64    = 2047
 )
 
@@ -220,10 +220,10 @@ fn f64_to_decimal(mant u64, exp u64) Dec64 {
 	if exp == 0 {
 		// We subtract 2 so that the bounds computation has
 		// 2 additional bits.
-		e2 = 1 - bias64 - mantbits64 - 2
+		e2 = 1 - bias64 - int(mantbits64) - 2
 		m2 = mant
 	} else {
-		e2 = int(exp) - bias64 - mantbits64 - 2
+		e2 = int(exp) - bias64 - int(mantbits64) - 2
 		m2 = (u64(1)<<mantbits64) | mant
 	}
 	even          := (m2 & 1) == 0
diff --git a/vlib/strings/similarity.v b/vlib/strings/similarity.v
index 76b2c08ec8..d57e4fa22e 100644
--- a/vlib/strings/similarity.v
+++ b/vlib/strings/similarity.v
@@ -65,6 +65,6 @@ pub fn dice_coefficient(s1, s2 string) f32 {
 			intersection_size++
 		}
 	}
-	return (2.0 * intersection_size) / (f32(a.len) + f32(b.len) - 2)
+	return (2.0 * f32(intersection_size)) / (f32(a.len) + f32(b.len) - 2)
 }
 
diff --git a/vlib/sync/pool.v b/vlib/sync/pool.v
index cfe254ad68..8cbaf79b13 100644
--- a/vlib/sync/pool.v
+++ b/vlib/sync/pool.v
@@ -79,7 +79,7 @@ pub fn new_pool_processor(context PoolProcessorConfig) &PoolProcessor {
 		ntask: 0
 		ntask_mtx: new_mutex()
 		waitgroup: new_waitgroup()
-		thread_cb: context.callback
+		thread_cb: voidptr(context.callback)
 	}
 	return pool
 }
diff --git a/vlib/sync/sync_windows.c.v b/vlib/sync/sync_windows.c.v
index 09bb7874e7..df2b714d29 100644
--- a/vlib/sync/sync_windows.c.v
+++ b/vlib/sync/sync_windows.c.v
@@ -32,7 +32,7 @@ pub fn new_mutex() &Mutex {
 	sm := &Mutex{}
 	unsafe {
 		mut m := sm
-		m.mx = C.CreateMutex(0, false, 0)
+		m.mx = MHANDLE(C.CreateMutex(0, false, 0))
 		if isnil(m.mx) {
 			m.state = .broken // handle broken and mutex state are broken
 			return sm
@@ -44,7 +44,7 @@ pub fn new_mutex() &Mutex {
 pub fn (mut m Mutex) lock() {
 	// if mutex handle not initalized
 	if isnil(m.mx) {
-		m.mx = C.CreateMutex(0, false, 0)
+		m.mx = MHANDLE(C.CreateMutex(0, false, 0))
 		if isnil(m.mx) {
 			m.state = .broken // handle broken and mutex state are broken
 			return
diff --git a/vlib/time/time.v b/vlib/time/time.v
index fc6c2538fe..8449b230a6 100644
--- a/vlib/time/time.v
+++ b/vlib/time/time.v
@@ -106,7 +106,7 @@ pub fn new_time(t Time) Time {
 		hour: t.hour
 		minute: t.minute
 		second: t.second
-		unix: t.unix_time()
+		unix: u64(t.unix_time())
 	}
 	// TODO Use the syntax below when it works with reserved keywords like `unix`
 	// return {
@@ -134,12 +134,12 @@ pub fn (t Time) unix_time() int {
 // add_seconds returns a new time struct with an added number of seconds.
 pub fn (t Time) add_seconds(seconds int) Time {
 	// TODO Add(d time.Duration)
-	return unix(t.unix + seconds)
+	return unix(t.unix + u64(seconds))
 }
 
 // add_days returns a new time struct with an added number of days.
 pub fn (t Time) add_days(days int) Time {
-	return unix(t.unix + days * 3600 * 24)
+	return unix(t.unix + u64(i64(days) * 3600 * 24))
 }
 
 // since returns a number of seconds elapsed since a given time.
@@ -272,7 +272,7 @@ fn convert_ctime(t C.tm) Time {
 		hour: t.tm_hour
 		minute: t.tm_min
 		second: t.tm_sec
-		unix: make_unix_time(t)
+		unix: u64(make_unix_time(t))
 	}
 }
 
diff --git a/vlib/time/unix.v b/vlib/time/unix.v
index 74d60f95ab..6856884150 100644
--- a/vlib/time/unix.v
+++ b/vlib/time/unix.v
@@ -20,7 +20,7 @@ pub fn unix(abs int) Time {
 		hour: hr
 		minute: min
 		second: sec
-		unix: abs
+		unix: u64(abs)
 	}
 }
 
diff --git a/vlib/v/checker/check_types.v b/vlib/v/checker/check_types.v
index 30ab715a39..8894114145 100644
--- a/vlib/v/checker/check_types.v
+++ b/vlib/v/checker/check_types.v
@@ -7,8 +7,8 @@ import v.table
 
 pub fn (c &Checker) check_types(got, expected table.Type) bool {
 	t := c.table
-	got_idx := got.idx()
-	exp_idx := expected.idx()
+	got_idx := t.unalias_num_type(got).idx()
+	exp_idx := t.unalias_num_type(expected).idx()
 	// got_is_ptr := got.is_ptr()
 	exp_is_ptr := expected.is_ptr()
 	// println('check: $got_type_sym.name, $exp_type_sym.name')
@@ -125,3 +125,119 @@ pub fn (c &Checker) check_types(got, expected table.Type) bool {
 	}
 	return false
 }
+
+pub fn (c &Checker) promote(left_type, right_type table.Type) table.Type {
+	if left_type.is_ptr() || left_type.is_pointer() {
+		if right_type.is_int() {
+			return left_type
+		} else {
+			return table.void_type
+		}
+	} else if right_type.is_ptr() || right_type.is_pointer() {
+		if left_type.is_int() {
+			return right_type
+		} else {
+			return table.void_type
+		}
+	}
+	if left_type == right_type {
+		return left_type // strings, self defined operators
+	}
+	if right_type.is_number() && left_type.is_number() {
+		// sort the operands to save time
+		mut type_hi := left_type
+		mut type_lo := right_type
+		if type_hi.idx() < type_lo.idx() {
+			tmp := type_hi
+			type_hi = type_lo
+			type_lo = tmp
+		}
+		idx_hi := type_hi.idx()
+		idx_lo := type_lo.idx()
+		// the following comparisons rely on the order of the indices in atypes.v
+		if idx_hi == table.any_int_type_idx {
+			return type_lo
+		} else if idx_hi == table.any_flt_type_idx {
+			if idx_lo in table.float_type_idxs {
+				return type_lo
+			} else {
+				return table.void_type
+			}
+		} else if type_hi.is_float() {
+			if idx_hi == table.f32_type_idx {
+				if idx_lo in [table.int_type_idx, table.i64_type_idx, table.u32_type_idx, table.u64_type_idx] {
+					return table.void_type
+				} else {
+					return idx_hi
+				}
+			} else { // f64, any_flt
+				if idx_lo in [table.i64_type_idx, table.u64_type_idx] {
+					return table.void_type
+				} else {
+					return type_hi
+				}
+			}
+		} else if idx_lo >= table.byte_type_idx { // both operands are unsigned
+			return type_hi
+		} else if idx_lo >= table.i8_type_idx && idx_hi <= table.i64_type_idx { // both signed
+			return type_hi
+		} else if idx_hi - idx_lo < (table.byte_type_idx - table.i8_type_idx) {
+			return type_lo // conversion unsigned -> signed if signed type is larger
+		} else {
+			return table.void_type // conversion signed -> unsigned not allowed
+		}
+	} else {
+		return left_type // default to left if not automatic promotion possible
+	}
+}
+
+// TODO: promote(), assign_check(), symmetric_check() and check() overlap - should be rearranged
+pub fn (c &Checker) assign_check(got, expected table.Type) bool {
+	exp_idx := expected.idx()
+	got_idx := got.idx()
+	if exp_idx == got_idx {
+		return true
+	}
+	if exp_idx == table.voidptr_type_idx || exp_idx == table.byteptr_type_idx {
+		if got.is_ptr() || got.is_pointer() {
+			return true
+		}
+	}
+	// allow direct int-literal assignment for pointers for now
+	// maybe in the future optionals should be used for that
+	if expected.is_ptr() || expected.is_pointer() {
+		if got == table.any_int_type {
+			return true
+		}
+	}
+	if got_idx == table.voidptr_type_idx || got_idx == table.byteptr_type_idx {
+		if expected.is_ptr() || expected.is_pointer() {
+			return true
+		}
+	}
+	if !c.check_types(got, expected) { // TODO: this should go away...
+		return false
+	}
+	if c.promote(expected, got) != expected {
+		println('could not promote ${c.table.get_type_symbol(got).name} to ${c.table.get_type_symbol(expected).name}')
+		return false
+	}
+	return true
+}
+
+pub fn (c &Checker) symmetric_check(left, right table.Type) bool {
+	// allow direct int-literal assignment for pointers for now
+	// maybe in the future optionals should be used for that
+	if right.is_ptr() || right.is_pointer() {
+		if left == table.any_int_type {
+			return true
+		}
+	}
+	// allow direct int-literal assignment for pointers for now
+	if left.is_ptr() || left.is_pointer() {
+		if right == table.any_int_type {
+			return true
+		}
+	}
+	return c.check_types(left, right)
+}
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index ba3f23e7a3..22d5bb2dfa 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -362,11 +362,11 @@ pub fn (mut c Checker) struct_init(mut struct_init ast.StructInit) table.Type {
 				expr_type := c.expr(field.expr)
 				expr_type_sym := c.table.get_type_symbol(expr_type)
 				field_type_sym := c.table.get_type_symbol(info_field.typ)
-				if !c.check_types(expr_type, info_field.typ) {
+				if !c.assign_check(expr_type, info_field.typ) {
 					c.error('cannot assign `$expr_type_sym.name` as `$field_type_sym.name` for field `$info_field.name`',
 						field.pos)
 				}
-				if info_field.typ.is_ptr() && !expr_type.is_ptr() && !expr_type.is_number() {
+				if info_field.typ.is_ptr() && !expr_type.is_ptr() && !expr_type.is_pointer() && !expr_type.is_number() {
 					c.error('ref', field.pos)
 				}
 				struct_init.fields[i].typ = expr_type
@@ -408,6 +408,10 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 	infix_expr.right_type = right_type
 	right := c.table.get_type_symbol(right_type)
 	left := c.table.get_type_symbol(left_type)
+	left_default := c.table.get_type_symbol(c.table.mktyp(left_type))
+	left_pos := infix_expr.left.position()
+	right_pos := infix_expr.right.position()
+	mut return_type := left_type
 	// Single side check
 	// Place these branches according to ops' usage frequency to accelerate.
 	// TODO: First branch includes ops where single side check is not needed, or needed but hasn't been implemented.
@@ -417,22 +421,22 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 		.key_in, .not_in {
 			match right.kind {
 				.array {
-					right_sym := c.table.get_type_symbol(right.array_info().elem_type)
-					if left.kind != right_sym.kind {
-						c.error('the data type on the left of `$infix_expr.op.str()` does not match the array item type',
+					right_sym := c.table.get_type_symbol(c.table.mktyp(right.array_info().elem_type))
+					if left_default.kind != right_sym.kind {
+						c.error('the data type on the left of `$infix_expr.op.str()` (`$left.name`) does not match the array item type (`$right_sym.name`)',
 							infix_expr.pos)
 					}
 				}
 				.map {
-					key_sym := c.table.get_type_symbol(right.map_info().key_type)
-					if left.kind != key_sym.kind {
-						c.error('the data type on the left of `$infix_expr.op.str()` does not match the map key type',
+					key_sym := c.table.get_type_symbol(c.table.mktyp(right.map_info().key_type))
+					if left_default.kind != key_sym.kind {
+						c.error('the data type on the left of `$infix_expr.op.str()` (`$left.name`) does not match the map key type `$key_sym.name`',
 							infix_expr.pos)
 					}
 				}
 				.string {
 					if left.kind != .string {
-						c.error('the data type on the left of `$infix_expr.op.str()` must be a string',
+						c.error('the data type on the left of `$infix_expr.op.str()` must be a string (is `$left.name`)',
 							infix_expr.pos)
 					}
 				}
@@ -443,15 +447,43 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 			}
 			return table.bool_type
 		}
-		.plus, .minus, .mul, .div {
-			if infix_expr.op == .div && (infix_expr.right is ast.IntegerLiteral && infix_expr.right.str() ==
-				'0' || infix_expr.right is ast.FloatLiteral && infix_expr.right.str().f64() == 0.0) {
-				c.error('division by zero', infix_expr.right.position())
-			}
-			if left.kind in [.array, .array_fixed, .map, .struct_] && !left.has_method(infix_expr.op.str()) {
-				c.error('mismatched types `$left.name` and `$right.name`', infix_expr.left.position())
-			} else if right.kind in [.array, .array_fixed, .map, .struct_] && !right.has_method(infix_expr.op.str()) {
-				c.error('mismatched types `$left.name` and `$right.name`', infix_expr.right.position())
+		.plus, .minus, .mul, .div, .mod, .xor, .amp, .pipe { // binary operators that expect matching types
+			if left.kind in [.array, .array_fixed, .map, .struct_] {
+				if left.has_method(infix_expr.op.str()) {
+					return_type = left_type
+				} else {
+					c.error('mismatched types `$left.name` and `$right.name`', left_pos)
+				}
+			} else if right.kind in [.array, .array_fixed, .map, .struct_] {
+				if right.has_method(infix_expr.op.str()) {
+					return_type = right_type
+				} else {
+					c.error('mismatched types `$left.name` and `$right.name`', right_pos)
+				}
+			} else {
+				promoted_type := c.promote(c.table.unalias_num_type(left_type), c.table.unalias_num_type(right_type))
+				if promoted_type.idx() == table.void_type_idx {
+					c.error('mismatched types `$left.name` and `$right.name`', infix_expr.pos)
+				} else if promoted_type.is_float() {
+					if infix_expr.op in [.mod, .xor, .amp, .pipe] {
+						side := if left_type == promoted_type { 'left' } else { 'right' }
+						pos := if left_type == promoted_type { left_pos } else { right_pos }
+						name :=  if left_type == promoted_type { left.name } else { right.name }
+						if infix_expr.op == .mod {
+							c.error('float modulo not allowed, use math.fmod() instead', pos)
+						} else {
+							c.error('$side type of `${infix_expr.op.str()}` cannot be non-integer type $name', pos)
+						}
+					}
+				}
+				if infix_expr.op in [.div, .mod] {
+					if infix_expr.right is ast.IntegerLiteral && infix_expr.right.str() == '0' ||
+						infix_expr.right is ast.FloatLiteral && infix_expr.right.str().f64() == 0.0 {
+						oper := if infix_expr.op == .div { 'division' } else { 'modulo' }
+						c.error('$oper by zero', right_pos)
+					}
+				}
+				return_type = promoted_type
 			}
 		}
 		.left_shift {
@@ -463,11 +495,10 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 				if left_value_sym.kind == .interface_ {
 					if right.kind != .array {
 						// []Animal << Cat
-						c.type_implements(right_type, left_value_type, infix_expr.right.position())
+						c.type_implements(right_type, left_value_type, right_pos)
 					} else {
 						// []Animal << Cat
-						c.type_implements(c.table.value_type(right_type), left_value_type,
-							infix_expr.right.position())
+						c.type_implements(c.table.value_type(right_type), left_value_type, right_pos)
 					}
 					return table.void_type
 				}
@@ -481,13 +512,13 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 					return table.void_type
 				}
 				s := left.name.replace('array_', '[]')
-				c.error('cannot append `$right.name` to `$s`', infix_expr.right.position())
+				c.error('cannot append `$right.name` to `$s`', right_pos)
 				return table.void_type
 			} else if !left.is_int() {
-				c.error('cannot shift type $right.name into non-integer type $left.name', infix_expr.left.position())
+				c.error('cannot shift type $right.name into non-integer type $left.name', left_pos)
 				return table.void_type
 			} else if !right.is_int() {
-				c.error('cannot shift non-integer type $right.name into type $left.name', infix_expr.right.position())
+				c.error('cannot shift non-integer type $right.name into type $left.name', right_pos)
 				return table.void_type
 			}
 		}
@@ -499,33 +530,6 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 			}
 			return table.bool_type
 		}
-		.amp, .pipe, .xor {
-			if !left.is_int() {
-				c.error('left type of `${infix_expr.op.str()}` cannot be non-integer type $left.name',
-					infix_expr.left.position())
-			} else if !right.is_int() {
-				c.error('right type of `${infix_expr.op.str()}` cannot be non-integer type $right.name',
-					infix_expr.right.position())
-			}
-		}
-		.mod {
-			if left.is_int() && !right.is_int() {
-				c.error('mismatched types `$left.name` and `$right.name`', infix_expr.right.position())
-			} else if !left.is_int() && right.is_int() {
-				c.error('mismatched types `$left.name` and `$right.name`', infix_expr.left.position())
-			} else if left.kind == .f32 && right.kind == .f32 || left.kind == .f64 && right.kind ==
-				.f64 {
-				c.error('float modulo not allowed, use math.fmod() instead', infix_expr.left.position())
-			} else if left.kind in [.f32, .f64, .string, .array, .array_fixed, .map, .struct_] &&
-				!left.has_method(infix_expr.op.str()) {
-				c.error('mismatched types `$left.name` and `$right.name`', infix_expr.left.position())
-			} else if right.kind in [.f32, .f64, .string, .array, .array_fixed, .map, .struct_] &&
-				!right.has_method(infix_expr.op.str()) {
-				c.error('mismatched types `$left.name` and `$right.name`', infix_expr.right.position())
-			} else if infix_expr.right is ast.IntegerLiteral && infix_expr.right.str() == '0' {
-				c.error('modulo by zero', infix_expr.right.position())
-			}
-		}
 		else {}
 	}
 	// TODO: Absorb this block into the above single side check block to accelerate.
@@ -539,7 +543,7 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 			infix_expr.pos)
 	}
 	// Dual sides check (compatibility check)
-	if !c.check_types(right_type, left_type) {
+	if !c.symmetric_check(right_type, left_type) {
 		// for type-unresolved consts
 		if left_type == table.void_type || right_type == table.void_type {
 			return table.void_type
@@ -550,7 +554,7 @@ pub fn (mut c Checker) infix_expr(mut infix_expr ast.InfixExpr) table.Type {
 	return if infix_expr.op.is_relational() {
 		table.bool_type
 	} else {
-		left_type
+		return_type
 	}
 }
 
@@ -678,7 +682,7 @@ fn (mut c Checker) assign_expr(mut assign_expr ast.AssignExpr) {
 		else {}
 	}
 	// Dual sides check (compatibility check)
-	if !c.check_types(right_type, left_type) {
+	if !c.assign_check(right_type, left_type) {
 		left_type_sym := c.table.get_type_symbol(left_type)
 		right_type_sym := c.table.get_type_symbol(right_type)
 		c.error('cannot assign `$right_type_sym.name` to variable `${assign_expr.left.str()}` of type `$left_type_sym.name`',
@@ -1268,12 +1272,15 @@ pub fn (mut c Checker) assign_stmt(mut assign_stmt ast.AssignStmt) {
 		} else if i < assign_stmt.right.len { // only once for multi return
 			c.check_expr_opt_call(assign_stmt.right[i], assign_stmt.right_types[i])
 		}
-		val_type := assign_stmt.right_types[i]
+		mut val_type := assign_stmt.right_types[i]
 		// check variable name for beginning with capital letter 'Abc'
 		is_decl := assign_stmt.op == .decl_assign
 		if is_decl && ident.name != '_' {
 			c.check_valid_snake_case(ident.name, 'variable name', ident.pos)
 		}
+		if assign_stmt.op == .decl_assign {
+			val_type = c.table.mktyp(val_type)
+		}
 		mut ident_var_info := ident.var_info()
 		if assign_stmt.op == .assign {
 			c.fail_if_immutable(ident)
@@ -1301,12 +1308,12 @@ pub fn (mut c Checker) array_init(mut array_init ast.ArrayInit) table.Type {
 	if array_init.typ != table.void_type {
 		if array_init.exprs.len == 0 {
 			if array_init.has_cap {
-				if c.expr(array_init.cap_expr) != table.int_type {
+				if c.expr(array_init.cap_expr) !in [table.int_type, table.any_int_type] {
 					c.error('array cap needs to be an int', array_init.pos)
 				}
 			}
 			if array_init.has_len {
-				if c.expr(array_init.len_expr) != table.int_type {
+				if c.expr(array_init.len_expr) !in [table.int_type, table.any_int_type] {
 					c.error('array len needs to be an int', array_init.pos)
 				}
 			}
@@ -1316,12 +1323,12 @@ pub fn (mut c Checker) array_init(mut array_init ast.ArrayInit) table.Type {
 	// a = []
 	if array_init.exprs.len == 0 {
 		if array_init.has_cap {
-			if c.expr(array_init.cap_expr) != table.int_type {
+			if c.expr(array_init.cap_expr) !in [table.int_type, table.any_int_type] {
 				c.error('array cap needs to be an int', array_init.pos)
 			}
 		}
 		if array_init.has_len {
-			if c.expr(array_init.len_expr) != table.int_type {
+			if c.expr(array_init.len_expr) !in [table.int_type, table.any_int_type] {
 				c.error('array len needs to be an int', array_init.pos)
 			}
 		}
@@ -1372,8 +1379,8 @@ pub fn (mut c Checker) array_init(mut array_init ast.ArrayInit) table.Type {
 			}
 			// The first element's type
 			if i == 0 {
-				elem_type = typ
-				c.expected_type = typ
+				elem_type = c.table.mktyp(typ)
+				c.expected_type = elem_type
 				continue
 			}
 			if !c.check_types(elem_type, typ) {
@@ -1492,7 +1499,7 @@ fn (mut c Checker) stmt(node ast.Stmt) {
 				c.const_decl = field.name
 				c.const_deps << field.name
 				typ := c.expr(field.expr)
-				it.fields[i].typ = typ
+				it.fields[i].typ = c.table.mktyp(typ)
 				for cd in c.const_deps {
 					for j, f in it.fields {
 						if j != i && cd in field_names && cd == f.name && j !in done_fields {
@@ -1748,7 +1755,7 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
 			return c.enum_val(mut it)
 		}
 		ast.FloatLiteral {
-			return table.f64_type
+			return table.any_flt_type
 		}
 		ast.Ident {
 			// c.checked_ident = it.name
@@ -1770,7 +1777,7 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
 			return c.infix_expr(mut it)
 		}
 		ast.IntegerLiteral {
-			return table.int_type
+			return table.any_int_type
 		}
 		ast.MapInit {
 			return c.map_init(mut it)
@@ -1805,7 +1812,7 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
 			return c.selector_expr(mut it)
 		}
 		ast.SizeOf {
-			return table.int_type
+			return table.u32_type
 		}
 		ast.StringLiteral {
 			if it.language == .c {
@@ -2140,10 +2147,33 @@ pub fn (mut c Checker) if_expr(mut node ast.IfExpr) table.Type {
 						// first branch of if expression
 						node.is_expr = true
 						node.typ = last_expr.typ
-					} else {
-						c.error('mismatched types `${c.table.type_to_str(node.typ)}` and `${c.table.type_to_str(last_expr.typ)}`',
-							node.pos)
+						continue
+					} else if node.typ in [table.any_flt_type, table.any_int_type] {
+						if node.typ == table.any_int_type {
+							if last_expr.typ.is_int() || last_expr.typ.is_float() {
+								node.typ = last_expr.typ
+								continue
+							} 
+						} else { // node.typ == any_float
+							if last_expr.typ.is_float() {
+								node.typ = last_expr.typ
+								continue
+							}
+						}
 					}
+					if last_expr.typ in [table.any_flt_type, table.any_int_type] {
+						if last_expr.typ == table.any_int_type {
+							if node.typ.is_int() || node.typ.is_float() {
+								continue
+							} 
+						} else { // expr_type == any_float
+							if node.typ.is_float() {
+								continue
+							}
+						}
+					}
+					c.error('mismatched types `${c.table.type_to_str(node.typ)}` and `${c.table.type_to_str(last_expr.typ)}`',
+							node.pos)
 				}
 			} else {
 				c.error('`if` expression requires an expression as the last statement of every branch',
@@ -2151,6 +2181,12 @@ pub fn (mut c Checker) if_expr(mut node ast.IfExpr) table.Type {
 			}
 		}
 	}
+	// if only untyped literals were given default to int/f64
+	if node.typ == table.any_int_type {
+		node.typ = table.int_type
+	} else if  node.typ == table.any_flt_type {
+		node.typ = table.f64_type
+	}
 	if expr_required {
 		if !node.has_else {
 			c.error('`if` expression needs `else` clause', node.pos)
diff --git a/vlib/v/checker/tests/add_op_wrong_left_type_err_a.out b/vlib/v/checker/tests/add_op_wrong_left_type_err_a.out
index 706bbb1941..cee46d4a7e 100644
--- a/vlib/v/checker/tests/add_op_wrong_left_type_err_a.out
+++ b/vlib/v/checker/tests/add_op_wrong_left_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/add_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `int`
+vlib/v/checker/tests/add_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `any_int` 
     1 | struct A{}
     2 | fn main() {
     3 |     A{} + 10
diff --git a/vlib/v/checker/tests/add_op_wrong_left_type_err_b.out b/vlib/v/checker/tests/add_op_wrong_left_type_err_b.out
index 54e8fbd155..864151db2c 100644
--- a/vlib/v/checker/tests/add_op_wrong_left_type_err_b.out
+++ b/vlib/v/checker/tests/add_op_wrong_left_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/add_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `int`
+vlib/v/checker/tests/add_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `any_int` 
     1 | fn main() {
     2 |     [1,2,3] + 10
       |     ~~~~~~~
diff --git a/vlib/v/checker/tests/add_op_wrong_left_type_err_c.out b/vlib/v/checker/tests/add_op_wrong_left_type_err_c.out
index 72f0107bdc..7f260d0c2e 100644
--- a/vlib/v/checker/tests/add_op_wrong_left_type_err_c.out
+++ b/vlib/v/checker/tests/add_op_wrong_left_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/add_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `int`
+vlib/v/checker/tests/add_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `any_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     a + 10
diff --git a/vlib/v/checker/tests/add_op_wrong_right_type_err_a.out b/vlib/v/checker/tests/add_op_wrong_right_type_err_a.out
index 56ad595917..d77e2624ff 100644
--- a/vlib/v/checker/tests/add_op_wrong_right_type_err_a.out
+++ b/vlib/v/checker/tests/add_op_wrong_right_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/add_op_wrong_right_type_err_a.v:3:10: error: mismatched types `int` and `A`
+vlib/v/checker/tests/add_op_wrong_right_type_err_a.v:3:10: error: mismatched types `any_int` and `A` 
     1 | struct A{}
     2 | fn main() {
     3 |     10 + A{}
diff --git a/vlib/v/checker/tests/add_op_wrong_right_type_err_b.out b/vlib/v/checker/tests/add_op_wrong_right_type_err_b.out
index a886cf04e7..8d61f81c2a 100644
--- a/vlib/v/checker/tests/add_op_wrong_right_type_err_b.out
+++ b/vlib/v/checker/tests/add_op_wrong_right_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/add_op_wrong_right_type_err_b.v:2:10: error: mismatched types `int` and `array_int`
+vlib/v/checker/tests/add_op_wrong_right_type_err_b.v:2:10: error: mismatched types `any_int` and `array_int` 
     1 | fn main() {
     2 |     10 + [1,2,3]
       |          ~~~~~~~
diff --git a/vlib/v/checker/tests/add_op_wrong_right_type_err_c.out b/vlib/v/checker/tests/add_op_wrong_right_type_err_c.out
index 4a4a3aedbb..085c32fb86 100644
--- a/vlib/v/checker/tests/add_op_wrong_right_type_err_c.out
+++ b/vlib/v/checker/tests/add_op_wrong_right_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/add_op_wrong_right_type_err_c.v:3:10: error: mismatched types `int` and `map_string_int`
+vlib/v/checker/tests/add_op_wrong_right_type_err_c.v:3:10: error: mismatched types `any_int` and `map_string_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     10 + a
diff --git a/vlib/v/checker/tests/bit_op_wrong_left_type_err.out b/vlib/v/checker/tests/bit_op_wrong_left_type_err.out
index bb4ba57bc0..0077eeff03 100644
--- a/vlib/v/checker/tests/bit_op_wrong_left_type_err.out
+++ b/vlib/v/checker/tests/bit_op_wrong_left_type_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/bit_op_wrong_left_type_err.v:2:2: error: left type of `&` cannot be non-integer type f64
+vlib/v/checker/tests/bit_op_wrong_left_type_err.v:2:2: error: left type of `&` cannot be non-integer type any_float 
     1 | fn main() {
     2 |     0.5 & 1
       |     ~~~
diff --git a/vlib/v/checker/tests/bit_op_wrong_right_type_err.out b/vlib/v/checker/tests/bit_op_wrong_right_type_err.out
index 28d7cdb3b8..3e36bb91a1 100644
--- a/vlib/v/checker/tests/bit_op_wrong_right_type_err.out
+++ b/vlib/v/checker/tests/bit_op_wrong_right_type_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/bit_op_wrong_right_type_err.v:2:6: error: right type of `|` cannot be non-integer type f64
+vlib/v/checker/tests/bit_op_wrong_right_type_err.v:2:6: error: right type of `|` cannot be non-integer type any_float 
     1 | fn main() {
     2 |     1 | 0.5
       |         ~~~
diff --git a/vlib/v/checker/tests/cast_string_err.out b/vlib/v/checker/tests/cast_string_err.out
index a5b128b429..794ca79b29 100644
--- a/vlib/v/checker/tests/cast_string_err.out
+++ b/vlib/v/checker/tests/cast_string_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/cast_string_err.v:2:14: error: cannot cast type `int` to string, use `x.str()` instead
+vlib/v/checker/tests/cast_string_err.v:2:14: error: cannot cast type `any_int` to string, use `x.str()` instead 
     1 | fn main() {
     2 |     a := string(1)
       |                 ^
diff --git a/vlib/v/checker/tests/div_op_wrong_left_type_err_a.out b/vlib/v/checker/tests/div_op_wrong_left_type_err_a.out
index 76c663ceeb..410eb4a874 100644
--- a/vlib/v/checker/tests/div_op_wrong_left_type_err_a.out
+++ b/vlib/v/checker/tests/div_op_wrong_left_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/div_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `int`
+vlib/v/checker/tests/div_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `any_int` 
     1 | struct A{}
     2 | fn main() {
     3 |     A{} / 10
diff --git a/vlib/v/checker/tests/div_op_wrong_left_type_err_b.out b/vlib/v/checker/tests/div_op_wrong_left_type_err_b.out
index 1dd125f53b..3706ba2548 100644
--- a/vlib/v/checker/tests/div_op_wrong_left_type_err_b.out
+++ b/vlib/v/checker/tests/div_op_wrong_left_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/div_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `int`
+vlib/v/checker/tests/div_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `any_int` 
     1 | fn main() {
     2 |     [1,2,3] / 10
       |     ~~~~~~~
diff --git a/vlib/v/checker/tests/div_op_wrong_left_type_err_c.out b/vlib/v/checker/tests/div_op_wrong_left_type_err_c.out
index 7c0144e001..336adaf5df 100644
--- a/vlib/v/checker/tests/div_op_wrong_left_type_err_c.out
+++ b/vlib/v/checker/tests/div_op_wrong_left_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/div_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `int`
+vlib/v/checker/tests/div_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `any_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     a / 10
diff --git a/vlib/v/checker/tests/div_op_wrong_right_type_err_a.out b/vlib/v/checker/tests/div_op_wrong_right_type_err_a.out
index c46df5ace1..747f8deda7 100644
--- a/vlib/v/checker/tests/div_op_wrong_right_type_err_a.out
+++ b/vlib/v/checker/tests/div_op_wrong_right_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/div_op_wrong_right_type_err_a.v:3:10: error: mismatched types `int` and `A`
+vlib/v/checker/tests/div_op_wrong_right_type_err_a.v:3:10: error: mismatched types `any_int` and `A` 
     1 | struct A{}
     2 | fn main() {
     3 |     10 / A{}
diff --git a/vlib/v/checker/tests/div_op_wrong_right_type_err_b.out b/vlib/v/checker/tests/div_op_wrong_right_type_err_b.out
index 7497157e16..4dca5f2ce2 100644
--- a/vlib/v/checker/tests/div_op_wrong_right_type_err_b.out
+++ b/vlib/v/checker/tests/div_op_wrong_right_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/div_op_wrong_right_type_err_b.v:2:10: error: mismatched types `int` and `array_int`
+vlib/v/checker/tests/div_op_wrong_right_type_err_b.v:2:10: error: mismatched types `any_int` and `array_int` 
     1 | fn main() {
     2 |     10 / [1,2,3]
       |          ~~~~~~~
diff --git a/vlib/v/checker/tests/div_op_wrong_right_type_err_c.out b/vlib/v/checker/tests/div_op_wrong_right_type_err_c.out
index c024c95a5c..834c6f72ef 100644
--- a/vlib/v/checker/tests/div_op_wrong_right_type_err_c.out
+++ b/vlib/v/checker/tests/div_op_wrong_right_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/div_op_wrong_right_type_err_c.v:3:10: error: mismatched types `int` and `map_string_int`
+vlib/v/checker/tests/div_op_wrong_right_type_err_c.v:3:10: error: mismatched types `any_int` and `map_string_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     10 / a
diff --git a/vlib/v/checker/tests/for-in-index-type.out b/vlib/v/checker/tests/for-in-index-type.out
index b4ce5eb609..40c8bacaf8 100644
--- a/vlib/v/checker/tests/for-in-index-type.out
+++ b/vlib/v/checker/tests/for-in-index-type.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/for-in-index-type.v:2:11: error: for in: cannot index `int`
+vlib/v/checker/tests/for-in-index-type.v:2:11: error: for in: cannot index `any_int` 
     1 | fn main() {
     2 |     for a in 52 {
       |              ~~
diff --git a/vlib/v/checker/tests/if_expr_mismatch.out b/vlib/v/checker/tests/if_expr_mismatch.out
index 04ce5c54b9..0ab04350cd 100644
--- a/vlib/v/checker/tests/if_expr_mismatch.out
+++ b/vlib/v/checker/tests/if_expr_mismatch.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/if_expr_mismatch.v:2:7: error: mismatched types `string` and `int`
+vlib/v/checker/tests/if_expr_mismatch.v:2:7: error: mismatched types `string` and `any_int` 
     1 | fn main() {
     2 |     s := if true { '12' } else { 12 }
       |          ~~
diff --git a/vlib/v/checker/tests/in_mismatch_type.out b/vlib/v/checker/tests/in_mismatch_type.out
index 5cdb2492d2..7bc6c3778c 100644
--- a/vlib/v/checker/tests/in_mismatch_type.out
+++ b/vlib/v/checker/tests/in_mismatch_type.out
@@ -1,76 +1,76 @@
-vlib/v/checker/tests/in_mismatch_type.v:10:7: error: the data type on the left of `in` does not match the array item type 
+vlib/v/checker/tests/in_mismatch_type.v:10:7: error: the data type on the left of `in` (`any_int`) does not match the array item type (`string`) 
     8 |     }
     9 |     s := 'abcd'
    10 |     if 1 in a_s {
       |          ~~
    11 |         println('ok')
    12 |     }
-vlib/v/checker/tests/in_mismatch_type.v:13:7: error: the data type on the left of `in` does not match the map key type
+vlib/v/checker/tests/in_mismatch_type.v:13:7: error: the data type on the left of `in` (`any_int`) does not match the map key type `string` 
    11 |         println('ok')
    12 |     }
    13 |     if 2 in m {
       |          ~~
    14 |         println('yeah')
    15 |     }
-vlib/v/checker/tests/in_mismatch_type.v:16:7: error: the data type on the left of `in` must be a string
+vlib/v/checker/tests/in_mismatch_type.v:16:7: error: the data type on the left of `in` must be a string (is `any_int`) 
    14 |         println('yeah')
    15 |     }
    16 |     if 3 in s {
       |          ~~
    17 |         println('dope')
    18 |     }
-vlib/v/checker/tests/in_mismatch_type.v:19:9: error: the data type on the left of `in` must be a string 
+vlib/v/checker/tests/in_mismatch_type.v:19:9: error: the data type on the left of `in` must be a string (is `byte`) 
    17 |         println('dope')
    18 |     }
    19 |     if `a` in s {
       |            ~~
    20 |         println("oh no :'(")
    21 |     }
-vlib/v/checker/tests/in_mismatch_type.v:22:7: error: `in` can only be used with an array/map/string
+vlib/v/checker/tests/in_mismatch_type.v:22:7: error: `in` can only be used with an array/map/string 
    20 |         println("oh no :'(")
    21 |     }
    22 |     if 1 in 12 {
       |          ~~
    23 |         println('right')
    24 |     }
-vlib/v/checker/tests/in_mismatch_type.v:25:12: error: the data type on the left of `in` does not match the map key type
+vlib/v/checker/tests/in_mismatch_type.v:25:12: error: the data type on the left of `in` (`Int`) does not match the map key type `string` 
    23 |         println('right')
    24 |     }
    25 |     if Int(2) in m {
       |               ~~
    26 |         println('yeah')
    27 |     }
-vlib/v/checker/tests/in_mismatch_type.v:28:9: error: the data type on the left of `in` does not match the array item type
+vlib/v/checker/tests/in_mismatch_type.v:28:9: error: the data type on the left of `in` (`string`) does not match the array item type (`int`) 
    26 |         println('yeah')
    27 |     }
    28 |     if '3' in a_i {
       |            ~~
    29 |         println('sure')
    30 |     }
-vlib/v/checker/tests/in_mismatch_type.v:31:9: error: the data type on the left of `in` does not match the array item type
+vlib/v/checker/tests/in_mismatch_type.v:31:9: error: the data type on the left of `in` (`string`) does not match the array item type (`int`) 
    29 |         println('sure')
    30 |     }
    31 |     if '2' in a_i {
       |            ~~
    32 |         println('all right')
    33 |     }
-vlib/v/checker/tests/in_mismatch_type.v:34:7: error: the data type on the left of `!in` does not match the array item type
+vlib/v/checker/tests/in_mismatch_type.v:34:7: error: the data type on the left of `!in` (`any_int`) does not match the array item type (`string`) 
    32 |         println('all right')
    33 |     }
    34 |     if 1 !in a_s {
       |          ~~~
    35 |         println('ok')
    36 |     }
-vlib/v/checker/tests/in_mismatch_type.v:37:9: error: the data type on the left of `!in` does not match the array item type 
+vlib/v/checker/tests/in_mismatch_type.v:37:9: error: the data type on the left of `!in` (`string`) does not match the array item type (`int`) 
    35 |         println('ok')
    36 |     }
    37 |     if '1' !in a_i {
       |            ~~~
    38 |         println('good')
    39 |     }
-vlib/v/checker/tests/in_mismatch_type.v:41:7: error: the data type on the left of `!in` does not match the map key type
+vlib/v/checker/tests/in_mismatch_type.v:41:7: error: the data type on the left of `!in` (`any_int`) does not match the map key type `string` 
    39 |     }
-   40 |
+   40 | 
    41 |     if 5 !in m {
       |          ~~~
    42 |         println('yay')
diff --git a/vlib/v/checker/tests/is_type_not_exist.out b/vlib/v/checker/tests/is_type_not_exist.out
index 79385d0048..d732a34149 100644
--- a/vlib/v/checker/tests/is_type_not_exist.out
+++ b/vlib/v/checker/tests/is_type_not_exist.out
@@ -1,5 +1,12 @@
-vlib/v/checker/tests/is_type_not_exist.v:8:10: error: is: type `SomethingThatDontExist` does not exist
+vlib/v/checker/tests/is_type_not_exist.v:4:2: error: cannot use type `any_int` as type `Integer` in argument 1 to `fn_with_sum_type_param` 
+    2 | 
+    3 | fn main() {
+    4 |     fn_with_sum_type_param(1)
+      |     ~~~~~~~~~~~~~~~~~~~~~~~~~
+    5 | }
     6 |
+vlib/v/checker/tests/is_type_not_exist.v:8:10: error: is: type `SomethingThatDontExist` does not exist 
+    6 | 
     7 | fn fn_with_sum_type_param(i Integer) {
     8 |     if i is SomethingThatDontExist {
       |             ~~~~~~~~~~~~~~~~~~~~~~
diff --git a/vlib/v/checker/tests/minus_op_wrong_left_type_err_a.out b/vlib/v/checker/tests/minus_op_wrong_left_type_err_a.out
index 6c20a705f8..2e7c7efbce 100644
--- a/vlib/v/checker/tests/minus_op_wrong_left_type_err_a.out
+++ b/vlib/v/checker/tests/minus_op_wrong_left_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/minus_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `int`
+vlib/v/checker/tests/minus_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `any_int` 
     1 | struct A{}
     2 | fn main() {
     3 |     A{} - 10
diff --git a/vlib/v/checker/tests/minus_op_wrong_left_type_err_b.out b/vlib/v/checker/tests/minus_op_wrong_left_type_err_b.out
index 19b2b68a40..65e835c096 100644
--- a/vlib/v/checker/tests/minus_op_wrong_left_type_err_b.out
+++ b/vlib/v/checker/tests/minus_op_wrong_left_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/minus_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `int`
+vlib/v/checker/tests/minus_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `any_int` 
     1 | fn main() {
     2 |     [1,2,3] - 10
       |     ~~~~~~~
diff --git a/vlib/v/checker/tests/minus_op_wrong_left_type_err_c.out b/vlib/v/checker/tests/minus_op_wrong_left_type_err_c.out
index 75e17e9358..714a7ee5b3 100644
--- a/vlib/v/checker/tests/minus_op_wrong_left_type_err_c.out
+++ b/vlib/v/checker/tests/minus_op_wrong_left_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/minus_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `int`
+vlib/v/checker/tests/minus_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `any_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     a - 10
diff --git a/vlib/v/checker/tests/minus_op_wrong_right_type_err_a.out b/vlib/v/checker/tests/minus_op_wrong_right_type_err_a.out
index 63bd1c7062..add2249e0c 100644
--- a/vlib/v/checker/tests/minus_op_wrong_right_type_err_a.out
+++ b/vlib/v/checker/tests/minus_op_wrong_right_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/minus_op_wrong_right_type_err_a.v:3:10: error: mismatched types `int` and `A`
+vlib/v/checker/tests/minus_op_wrong_right_type_err_a.v:3:10: error: mismatched types `any_int` and `A` 
     1 | struct A{}
     2 | fn main() {
     3 |     10 - A{}
diff --git a/vlib/v/checker/tests/minus_op_wrong_right_type_err_b.out b/vlib/v/checker/tests/minus_op_wrong_right_type_err_b.out
index e717b7af60..76a786551f 100644
--- a/vlib/v/checker/tests/minus_op_wrong_right_type_err_b.out
+++ b/vlib/v/checker/tests/minus_op_wrong_right_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/minus_op_wrong_right_type_err_b.v:2:10: error: mismatched types `int` and `array_int`
+vlib/v/checker/tests/minus_op_wrong_right_type_err_b.v:2:10: error: mismatched types `any_int` and `array_int` 
     1 | fn main() {
     2 |     10 - [1,2,3]
       |          ~~~~~~~
diff --git a/vlib/v/checker/tests/minus_op_wrong_right_type_err_c.out b/vlib/v/checker/tests/minus_op_wrong_right_type_err_c.out
index f37e415bcb..25c6184628 100644
--- a/vlib/v/checker/tests/minus_op_wrong_right_type_err_c.out
+++ b/vlib/v/checker/tests/minus_op_wrong_right_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/minus_op_wrong_right_type_err_c.v:3:10: error: mismatched types `int` and `map_string_int`
+vlib/v/checker/tests/minus_op_wrong_right_type_err_c.v:3:10: error: mismatched types `any_int` and `map_string_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     10 - a
diff --git a/vlib/v/checker/tests/mod_op_wrong_left_type_err_a.out b/vlib/v/checker/tests/mod_op_wrong_left_type_err_a.out
index 48f72a0cda..86fb067512 100644
--- a/vlib/v/checker/tests/mod_op_wrong_left_type_err_a.out
+++ b/vlib/v/checker/tests/mod_op_wrong_left_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_left_type_err_a.v:2:2: error: mismatched types `f64` and `int`
+vlib/v/checker/tests/mod_op_wrong_left_type_err_a.v:2:2: error: float modulo not allowed, use math.fmod() instead 
     1 | fn main() {
     2 |     0.5 % 1
       |     ~~~
diff --git a/vlib/v/checker/tests/mod_op_wrong_left_type_err_b.out b/vlib/v/checker/tests/mod_op_wrong_left_type_err_b.out
index 806b145642..ac813150fc 100644
--- a/vlib/v/checker/tests/mod_op_wrong_left_type_err_b.out
+++ b/vlib/v/checker/tests/mod_op_wrong_left_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_left_type_err_b.v:2:2: error: mismatched types `array_int` and `int`
+vlib/v/checker/tests/mod_op_wrong_left_type_err_b.v:2:2: error: mismatched types `array_int` and `any_int` 
     1 | fn main() {
     2 |     [1,2,3] % 1
       |     ~~~~~~~
diff --git a/vlib/v/checker/tests/mod_op_wrong_left_type_err_c.out b/vlib/v/checker/tests/mod_op_wrong_left_type_err_c.out
index bcea24d762..99b5337694 100644
--- a/vlib/v/checker/tests/mod_op_wrong_left_type_err_c.out
+++ b/vlib/v/checker/tests/mod_op_wrong_left_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_left_type_err_c.v:4:2: error: mismatched types `A` and `int`
+vlib/v/checker/tests/mod_op_wrong_left_type_err_c.v:4:2: error: mismatched types `A` and `any_int` 
     2 | fn main() {
     3 |     a := A{}
     4 |     a % 1
diff --git a/vlib/v/checker/tests/mod_op_wrong_left_type_err_d.out b/vlib/v/checker/tests/mod_op_wrong_left_type_err_d.out
index b55825c29b..bbf5235c3e 100644
--- a/vlib/v/checker/tests/mod_op_wrong_left_type_err_d.out
+++ b/vlib/v/checker/tests/mod_op_wrong_left_type_err_d.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_left_type_err_d.v:3:2: error: mismatched types `map_string_int` and `int`
+vlib/v/checker/tests/mod_op_wrong_left_type_err_d.v:3:2: error: mismatched types `map_string_int` and `any_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     a % 1
diff --git a/vlib/v/checker/tests/mod_op_wrong_right_type_err_a.out b/vlib/v/checker/tests/mod_op_wrong_right_type_err_a.out
index a3097a8ddf..989c42d4d0 100644
--- a/vlib/v/checker/tests/mod_op_wrong_right_type_err_a.out
+++ b/vlib/v/checker/tests/mod_op_wrong_right_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_right_type_err_a.v:2:6: error: mismatched types `int` and `f64`
+vlib/v/checker/tests/mod_op_wrong_right_type_err_a.v:2:6: error: float modulo not allowed, use math.fmod() instead 
     1 | fn main() {
     2 |     1 % 0.5
       |         ~~~
diff --git a/vlib/v/checker/tests/mod_op_wrong_right_type_err_b.out b/vlib/v/checker/tests/mod_op_wrong_right_type_err_b.out
index 9cdb1c0f9f..d43282c508 100644
--- a/vlib/v/checker/tests/mod_op_wrong_right_type_err_b.out
+++ b/vlib/v/checker/tests/mod_op_wrong_right_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_right_type_err_b.v:2:6: error: mismatched types `int` and `array_int`
+vlib/v/checker/tests/mod_op_wrong_right_type_err_b.v:2:6: error: mismatched types `any_int` and `array_int` 
     1 | fn main() {
     2 |     1 % [1,2,3]
       |         ~~~~~~~
diff --git a/vlib/v/checker/tests/mod_op_wrong_right_type_err_c.out b/vlib/v/checker/tests/mod_op_wrong_right_type_err_c.out
index 80b805799f..12dadd60be 100644
--- a/vlib/v/checker/tests/mod_op_wrong_right_type_err_c.out
+++ b/vlib/v/checker/tests/mod_op_wrong_right_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_right_type_err_c.v:4:6: error: mismatched types `int` and `A`
+vlib/v/checker/tests/mod_op_wrong_right_type_err_c.v:4:6: error: mismatched types `any_int` and `A` 
     2 | fn main() {
     3 |     a := A{}
     4 |     1 % a
diff --git a/vlib/v/checker/tests/mod_op_wrong_right_type_err_d.out b/vlib/v/checker/tests/mod_op_wrong_right_type_err_d.out
index b903190b45..2dd072bd1f 100644
--- a/vlib/v/checker/tests/mod_op_wrong_right_type_err_d.out
+++ b/vlib/v/checker/tests/mod_op_wrong_right_type_err_d.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mod_op_wrong_right_type_err_d.v:3:6: error: mismatched types `int` and `map_string_int`
+vlib/v/checker/tests/mod_op_wrong_right_type_err_d.v:3:6: error: mismatched types `any_int` and `map_string_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     1 % a
diff --git a/vlib/v/checker/tests/mul_op_wrong_left_type_err_a.out b/vlib/v/checker/tests/mul_op_wrong_left_type_err_a.out
index be1c509109..6ae6aba93a 100644
--- a/vlib/v/checker/tests/mul_op_wrong_left_type_err_a.out
+++ b/vlib/v/checker/tests/mul_op_wrong_left_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mul_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `int`
+vlib/v/checker/tests/mul_op_wrong_left_type_err_a.v:3:5: error: mismatched types `A` and `any_int` 
     1 | struct A{}
     2 | fn main() {
     3 |     A{} * 10
diff --git a/vlib/v/checker/tests/mul_op_wrong_left_type_err_b.out b/vlib/v/checker/tests/mul_op_wrong_left_type_err_b.out
index 222812e0c2..342042bc30 100644
--- a/vlib/v/checker/tests/mul_op_wrong_left_type_err_b.out
+++ b/vlib/v/checker/tests/mul_op_wrong_left_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mul_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `int`
+vlib/v/checker/tests/mul_op_wrong_left_type_err_b.v:2:5: error: mismatched types `array_int` and `any_int` 
     1 | fn main() {
     2 |     [1,2,3] * 10
       |     ~~~~~~~
diff --git a/vlib/v/checker/tests/mul_op_wrong_left_type_err_c.out b/vlib/v/checker/tests/mul_op_wrong_left_type_err_c.out
index 6c7397718d..3d1f7c5431 100644
--- a/vlib/v/checker/tests/mul_op_wrong_left_type_err_c.out
+++ b/vlib/v/checker/tests/mul_op_wrong_left_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mul_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `int`
+vlib/v/checker/tests/mul_op_wrong_left_type_err_c.v:3:5: error: mismatched types `map_string_int` and `any_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     a * 10
diff --git a/vlib/v/checker/tests/mul_op_wrong_left_type_err_d.out b/vlib/v/checker/tests/mul_op_wrong_left_type_err_d.out
new file mode 100644
index 0000000000..26303228ce
--- /dev/null
+++ b/vlib/v/checker/tests/mul_op_wrong_left_type_err_d.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/mul_op_wrong_left_type_err_d.v:6:11: error: infix expr: cannot use `any_float` (right expression) as `math.complex.Complex` 
+    4 | fn main() {
+    5 |     c1 := cmplx.complex(1,-2)
+    6 |     c2 := c1 * 2.0
+      |              ^
+    7 |     println(c2)
+    8 | }
diff --git a/vlib/v/checker/tests/mul_op_wrong_left_type_err_d.vv b/vlib/v/checker/tests/mul_op_wrong_left_type_err_d.vv
new file mode 100644
index 0000000000..e1a12f9777
--- /dev/null
+++ b/vlib/v/checker/tests/mul_op_wrong_left_type_err_d.vv
@@ -0,0 +1,8 @@
+import math
+import math.complex as cmplx
+
+fn main() {
+	c1 := cmplx.complex(1,-2)
+	c2 := c1 * 2.0
+	println(c2)
+}
diff --git a/vlib/v/checker/tests/mul_op_wrong_right_type_err_a.out b/vlib/v/checker/tests/mul_op_wrong_right_type_err_a.out
index ffc4e4e3f1..96cec13c52 100644
--- a/vlib/v/checker/tests/mul_op_wrong_right_type_err_a.out
+++ b/vlib/v/checker/tests/mul_op_wrong_right_type_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mul_op_wrong_right_type_err_a.v:3:10: error: mismatched types `int` and `A`
+vlib/v/checker/tests/mul_op_wrong_right_type_err_a.v:3:10: error: mismatched types `any_int` and `A` 
     1 | struct A{}
     2 | fn main() {
     3 |     10 * A{}
diff --git a/vlib/v/checker/tests/mul_op_wrong_right_type_err_b.out b/vlib/v/checker/tests/mul_op_wrong_right_type_err_b.out
index cca704c0c4..210d9022a8 100644
--- a/vlib/v/checker/tests/mul_op_wrong_right_type_err_b.out
+++ b/vlib/v/checker/tests/mul_op_wrong_right_type_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mul_op_wrong_right_type_err_b.v:2:10: error: mismatched types `int` and `array_int`
+vlib/v/checker/tests/mul_op_wrong_right_type_err_b.v:2:10: error: mismatched types `any_int` and `array_int` 
     1 | fn main() {
     2 |     10 * [1,2,3]
       |          ~~~~~~~
diff --git a/vlib/v/checker/tests/mul_op_wrong_right_type_err_c.out b/vlib/v/checker/tests/mul_op_wrong_right_type_err_c.out
index 5f419e150f..c32652ebca 100644
--- a/vlib/v/checker/tests/mul_op_wrong_right_type_err_c.out
+++ b/vlib/v/checker/tests/mul_op_wrong_right_type_err_c.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/mul_op_wrong_right_type_err_c.v:3:10: error: mismatched types `int` and `map_string_int`
+vlib/v/checker/tests/mul_op_wrong_right_type_err_c.v:3:10: error: mismatched types `any_int` and `map_string_int` 
     1 | fn main() {
     2 |     a := map[string]int
     3 |     10 * a
diff --git a/vlib/v/checker/tests/mul_op_wrong_right_type_err_d.out b/vlib/v/checker/tests/mul_op_wrong_right_type_err_d.out
new file mode 100644
index 0000000000..e5437495ab
--- /dev/null
+++ b/vlib/v/checker/tests/mul_op_wrong_right_type_err_d.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/mul_op_wrong_right_type_err_d.v:6:12: error: infix expr: cannot use `math.complex.Complex` (right expression) as `any_float` 
+    4 | fn main() {
+    5 |     c1 := cmplx.complex(1,-2)
+    6 |     c2 := 2.0 * c1
+      |               ^
+    7 |     println(c2)
+    8 | }
diff --git a/vlib/v/checker/tests/mul_op_wrong_right_type_err_d.vv b/vlib/v/checker/tests/mul_op_wrong_right_type_err_d.vv
new file mode 100644
index 0000000000..6f754fe5b9
--- /dev/null
+++ b/vlib/v/checker/tests/mul_op_wrong_right_type_err_d.vv
@@ -0,0 +1,8 @@
+import math
+import math.complex as cmplx
+
+fn main() {
+	c1 := cmplx.complex(1,-2)
+	c2 := 2.0 * c1
+	println(c2)
+}
diff --git a/vlib/v/checker/tests/return_type.out b/vlib/v/checker/tests/return_type.out
index 6a0c4c4af8..01c33a2e13 100644
--- a/vlib/v/checker/tests/return_type.out
+++ b/vlib/v/checker/tests/return_type.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/return_type.v:2:9: error: cannot use `int` as type `bool` in return argument
+vlib/v/checker/tests/return_type.v:2:9: error: cannot use `any_int` as type `bool` in return argument 
     1 | fn test() bool {
     2 |     return 100
       |            ~~~
diff --git a/vlib/v/checker/tests/shift_op_wrong_left_type_err.out b/vlib/v/checker/tests/shift_op_wrong_left_type_err.out
index 74da254a00..29e58a57fb 100644
--- a/vlib/v/checker/tests/shift_op_wrong_left_type_err.out
+++ b/vlib/v/checker/tests/shift_op_wrong_left_type_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/shift_op_wrong_left_type_err.v:2:2: error: cannot shift type int into non-integer type f64
+vlib/v/checker/tests/shift_op_wrong_left_type_err.v:2:2: error: cannot shift type any_int into non-integer type any_float 
     1 | fn main() {
     2 |     0.5 << 1
       |     ~~~
diff --git a/vlib/v/checker/tests/shift_op_wrong_right_type_err.out b/vlib/v/checker/tests/shift_op_wrong_right_type_err.out
index 8858a01256..71ccb5e141 100644
--- a/vlib/v/checker/tests/shift_op_wrong_right_type_err.out
+++ b/vlib/v/checker/tests/shift_op_wrong_right_type_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/shift_op_wrong_right_type_err.v:2:7: error: cannot shift non-integer type f64 into type int
+vlib/v/checker/tests/shift_op_wrong_right_type_err.v:2:7: error: cannot shift non-integer type any_float into type any_int 
     1 | fn main() {
     2 |     1 << 0.5
       |          ~~~
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index b24a3702c2..657fb6d1f8 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -272,7 +272,7 @@ pub fn (mut g Gen) finish() {
 	if g.pref.is_livemain || g.pref.is_liveshared {
 		g.generate_hotcode_reloader_code()
 	}
-	if g.fn_main != 0 {
+	if g.fn_main != voidptr(0) {
 		g.out.writeln('')
 		g.fn_decl = g.fn_main
 		g.gen_fn_decl(g.fn_main)
@@ -1728,7 +1728,7 @@ fn (mut g Gen) infix_expr(node ast.InfixExpr) {
 				}
 				else {}
 			}
-			styp := g.typ(left_type)
+			styp := g.typ(g.table.mktyp(left_type))
 			g.write('_IN($styp, ')
 			g.expr(node.left)
 			g.write(', ')
diff --git a/vlib/v/gen/js/js.v b/vlib/v/gen/js/js.v
index 7555ca1c4a..11e8918293 100644
--- a/vlib/v/gen/js/js.v
+++ b/vlib/v/gen/js/js.v
@@ -847,7 +847,7 @@ fn (mut g JsGen) gen_method_decl(it ast.FnDecl) {
 		g.writeln('')
 	}
 
-	g.fn_decl = 0
+	g.fn_decl = voidptr(0)
 }
 
 fn (mut g JsGen) fn_args(args []table.Arg, is_variadic bool) {
diff --git a/vlib/v/gen/x64/elf.v b/vlib/v/gen/x64/elf.v
index b3ad623d53..e232cc9581 100644
--- a/vlib/v/gen/x64/elf.v
+++ b/vlib/v/gen/x64/elf.v
@@ -65,14 +65,14 @@ pub fn (mut g Gen) generate_elf_header() {
 	g.write64(0) // p_offset
 	g.write64(segment_start) // p_vaddr addr:050
 	g.write64(segment_start) //
-	g.file_size_pos = g.buf.len
+	g.file_size_pos = i64(g.buf.len)
 	g.write64(0) // p_filesz PLACEHOLDER, set to file_size later // addr: 060
 	g.write64(0) // p_memsz
 	g.write64(0x1000) // p_align
 	// user code starts here at
 	// address: 00070 and a half
 	println('code_start_pos = $g.buf.len.hex()')
-	g.code_start_pos = g.buf.len
+	g.code_start_pos = i64(g.buf.len)
 	g.debug_pos = g.buf.len
 	g.call(placeholder) // call main function, it's not guaranteed to be the first, we don't know its address yet
 	g.println('call fn main')
diff --git a/vlib/v/gen/x64/gen.v b/vlib/v/gen/x64/gen.v
index 742873c33c..a73a0745e5 100644
--- a/vlib/v/gen/x64/gen.v
+++ b/vlib/v/gen/x64/gen.v
@@ -402,7 +402,7 @@ pub fn (mut g Gen) gen_loop_end(to, label int) {
 }
 
 pub fn (mut g Gen) save_main_fn_addr() {
-	g.main_fn_addr = g.buf.len
+	g.main_fn_addr = i64(g.buf.len)
 }
 
 pub fn (mut g Gen) gen_print_from_expr(expr ast.Expr, newline bool) {
diff --git a/vlib/v/scanner/scanner.v b/vlib/v/scanner/scanner.v
index ab21ff2744..6150ad26f5 100644
--- a/vlib/v/scanner/scanner.v
+++ b/vlib/v/scanner/scanner.v
@@ -58,7 +58,7 @@ pub fn new_scanner_file(file_path string, comments_mode CommentsMode) &Scanner {
 	}
 	raw_text := util.read_file( file_path ) or {
 		verror(err)
-		return 0
+		return voidptr(0)
 	}
 	mut s := new_scanner(raw_text, comments_mode) // .skip_comments)
 	// s.init_fmt()
diff --git a/vlib/v/table/table.v b/vlib/v/table/table.v
index 95a27683be..6694023d9e 100644
--- a/vlib/v/table/table.v
+++ b/vlib/v/table/table.v
@@ -195,6 +195,18 @@ pub fn (t &Table) get_type_name(typ Type) string {
 	return typ_sym.name
 }
 
+[inline]
+pub fn (t &Table) unalias_num_type(typ Type) Type {
+	sym := t.get_type_symbol(typ)
+	if sym.kind == .alias {
+		pt := (sym.info as Alias).parent_typ
+		if pt <= f64_type && pt >= void_type {
+			return pt
+		}
+	}
+	return typ
+}
+
 // this will override or register builtin type
 // allows prexisitng types added in register_builtins
 // to be overriden with their real type info
@@ -438,6 +450,21 @@ pub fn (t &Table) value_type(typ Type) Type {
 	return void_type
 }
 
+[inline]
+pub fn (t &Table) mktyp(typ Type) Type {
+	match typ {
+		any_flt_type {
+			return table.f64_type
+		}
+		any_int_type {
+			return table.int_type
+		}
+		else {
+			return typ
+		}
+	}
+}
+
 // Once we have a module format we can read from module file instead
 // this is not optimal
 pub fn (table &Table) qualify_module(mod, file_path string) string {
diff --git a/vlib/v/tests/num_lit_call_method_test.v b/vlib/v/tests/num_lit_call_method_test.v
index f717276e65..3346d3acb8 100644
--- a/vlib/v/tests/num_lit_call_method_test.v
+++ b/vlib/v/tests/num_lit_call_method_test.v
@@ -13,16 +13,16 @@ fn test_int_lit_call_method() {
 
 fn test_float_lit_call_method() {
 	x1 := -123.66.str()
-	assert x1 == '-1.2366e+02'
+	assert x1 == '-123.66'
 	x2 := 12.5e-2.str()
-	assert x2 == '1.25e-01'
+	assert x2 == '0.125'
 	x3 := .789.str()
-	assert x3 == '7.89e-01'
+	assert x3 == '0.789'
 	x4 := .003e2.str()
-	assert x4 == '3.e-01'
+	assert x4 == '0.3'
 	x5 := 2.e-3.str()
 	assert x5 == '2.e-03'
 	x6 := 5.0.str()
-	assert x6 == '5.e+00'
+	assert x6 == '5.'
 	// x7 := 5..str()    Syntax `5.` is allowed, but do not call method on it (`5..str()` is parsed as a range). Use `5.0.str()` instead.
 }