diff --git a/vlib/v/ast/table.v b/vlib/v/ast/table.v
index 84dcba1f5b..61032610b2 100644
--- a/vlib/v/ast/table.v
+++ b/vlib/v/ast/table.v
@@ -76,7 +76,6 @@ pub fn (mut t Table) free() {
 	}
 }
 
-pub const invalid_type_idx = -1
 pub const fn_type_escape_seq = [' ', '', '(', '_', ')', '']
 pub const map_cname_escape_seq = ['[', '_T_', ', ', '_', ']', '']
 
@@ -768,7 +767,7 @@ fn (mut t Table) rewrite_already_registered_symbol(typ TypeSymbol, existing_idx
 		}
 		return existing_idx
 	}
-	return ast.invalid_type_idx
+	return invalid_type_idx
 }
 
 @[inline]
@@ -1559,7 +1558,7 @@ pub fn (mut t Table) resolve_generic_static_type_name(fn_name string, generic_na
 			valid_generic := util.is_generic_type_name(generic_name)
 				&& generic_name in generic_names
 			if valid_generic {
-				name_type := Type(t.find_type_idx(generic_name)).set_flag(.generic)
+				name_type := idx_to_type(t.find_type_idx(generic_name)).set_flag(.generic)
 				if typ := t.resolve_generic_to_concrete(name_type, generic_names, concrete_types) {
 					return '${t.type_to_str(typ)}${fn_name[index..]}'
 				}
diff --git a/vlib/v/ast/types.v b/vlib/v/ast/types.v
index 4f47d16cf4..af5d7b9e84 100644
--- a/vlib/v/ast/types.v
+++ b/vlib/v/ast/types.v
@@ -15,7 +15,12 @@ import strings
 import v.pref
 import v.token
 
-pub type Type = int
+pub type Type = u32
+
+@[inline]
+pub fn idx_to_type(idx int) Type {
+	return Type(u32(idx))
+}
 
 pub struct UnknownTypeInfo {}
 
@@ -110,13 +115,13 @@ pub mut:
 }
 
 // max of 8
-pub enum TypeFlag {
-	option
-	result
-	variadic
-	generic
-	shared_f
-	atomic_f
+pub enum TypeFlag as u32 {
+	option   = 1 << 24
+	result   = 1 << 25
+	variadic = 1 << 26
+	generic  = 1 << 27
+	shared_f = 1 << 28
+	atomic_f = 1 << 29
 }
 
 /*
@@ -307,7 +312,7 @@ pub fn (t Type) is_full() bool {
 // return nr_muls for `t`
 @[inline]
 pub fn (t Type) nr_muls() int {
-	return (int(t) >> 16) & 0xff
+	return (t >> 16) & 0xff
 }
 
 // return true if `t` is a pointer (nr_muls>0)
@@ -315,7 +320,7 @@ pub fn (t Type) nr_muls() int {
 pub fn (t Type) is_ptr() bool {
 	// any normal pointer, i.e. &Type, &&Type etc;
 	// Note: voidptr, charptr and byteptr are NOT included!
-	return (int(t) >> 16) & 0xff != 0
+	return (t >> 16) & 0xff != 0
 }
 
 // is_pointer returns true if `typ` is any of the builtin pointer types (voidptr, byteptr, charptr)
@@ -334,7 +339,7 @@ pub fn (typ Type) is_voidptr() bool {
 // is_any_kind_of_pointer returns true if t is any type of pointer
 @[inline]
 pub fn (t Type) is_any_kind_of_pointer() bool {
-	return (int(t) >> 16) & 0xff != 0 || (u16(t) & 0xffff) in ast.pointer_type_idxs
+	return (t >> 16) & 0xff != 0 || (u16(t) & 0xffff) in ast.pointer_type_idxs
 }
 
 // set nr_muls on `t` and return it
@@ -343,50 +348,56 @@ pub fn (t Type) set_nr_muls(nr_muls int) Type {
 	if nr_muls < 0 || nr_muls > 255 {
 		panic('set_nr_muls: nr_muls must be between 0 & 255')
 	}
-	return int(t) & 0xff00ffff | int(u32(nr_muls) << 16)
+	return t & 0xff00ffff | u32(nr_muls) << 16
 }
 
 // increments nr_muls on `t` and return it
 @[inline]
 pub fn (t Type) ref() Type {
-	nr_muls := (int(t) >> 16) & 0xff
+	nr_muls := (t >> 16) & 0xff
 	if nr_muls == 255 {
 		panic('ref: nr_muls is already at max of 255')
 	}
-	return int(t) & 0xff00ffff | int(u32(nr_muls + 1) << 16)
+	return t & 0xff00ffff | (nr_muls + 1) << 16
 }
 
 // decrement nr_muls on `t` and return it
 @[inline]
 pub fn (t Type) deref() Type {
-	nr_muls := (int(t) >> 16) & 0xff
+	nr_muls := (t >> 16) & 0xff
 	if nr_muls == 0 {
 		panic('deref: type `${t}` is not a pointer')
 	}
-	return int(t) & 0xff00ffff | int(u32(nr_muls - 1) << 16)
+	return t & 0xff00ffff | (nr_muls - 1) << 16
 }
 
-// set `flag` on `t` and return `t`
+// has_flag returns whether the given named `flag` is set
+@[inline]
+pub fn (t Type) has_flag(flag TypeFlag) bool {
+	return (t & u32(flag)) != 0
+}
+
+// set_flag returns a new type, that is like the input `t`, but with the named `flag` set
 @[inline]
 pub fn (t Type) set_flag(flag TypeFlag) Type {
-	return int(t) | (1 << (int(flag) + 24))
+	return t | u32(flag)
 }
 
-// clear `flag` on `t` and return `t`
+// clear_flag returns a new type, that is like `t`, but with the named `flag` cleared
 @[inline]
 pub fn (t Type) clear_flag(flag TypeFlag) Type {
-	return int(t) & ~(1 << (int(flag) + 24))
+	return t & ~(u32(flag))
 }
 
-// clear all flags or multi flags
+// clear_flags returns a new type, based on `t`, but with cleared named `flags`
 @[inline]
 pub fn (t Type) clear_flags(flags ...TypeFlag) Type {
 	if flags.len == 0 {
-		return int(t) & 0xffffff
+		return t & 0xffffff
 	} else {
 		mut typ := int(t)
 		for flag in flags {
-			typ = typ & ~(1 << (int(flag) + 24))
+			typ = typ & ~(u32(flag))
 		}
 		return typ
 	}
@@ -395,18 +406,12 @@ pub fn (t Type) clear_flags(flags ...TypeFlag) Type {
 // clear option and result flags
 @[inline]
 pub fn (t Type) clear_option_and_result() Type {
-	return u32(t) & ~0x0300_0000
-}
-
-// return true if `flag` is set on `t`
-@[inline]
-pub fn (t Type) has_flag(flag TypeFlag) bool {
-	return int(t) & (1 << (int(flag) + 24)) != 0
+	return t & ~0x0300_0000
 }
 
 @[inline]
 pub fn (t Type) has_option_or_result() bool {
-	return u32(t) & 0x0300_0000 != 0
+	return t & 0x0300_0000 != 0
 }
 
 // debug returns a verbose representation of the information in ts, useful for tracing/debugging
@@ -594,6 +599,8 @@ pub fn (typ Type) is_bool() bool {
 	return typ.idx() == ast.bool_type_idx
 }
 
+pub const invalid_type_idx = -1
+pub const no_type_idx = 0
 pub const void_type_idx = 1
 pub const voidptr_type_idx = 2
 pub const byteptr_type_idx = 3
@@ -651,6 +658,8 @@ pub const number_type_idxs = [i8_type_idx, i16_type_idx, int_type_idx, i32_type_
 	rune_type_idx]
 pub const pointer_type_idxs = [voidptr_type_idx, byteptr_type_idx, charptr_type_idx, nil_type_idx]
 
+pub const invalid_type = idx_to_type(invalid_type_idx) // -1 is a purposefully invalid type, not by default, but to signify checker errors
+pub const no_type = idx_to_type(no_type_idx) // 0 is an invalid type, but it is useful for initialising default ast.Type values, in fields or before loops
 pub const void_type = new_type(void_type_idx)
 pub const ovoid_type = new_type(void_type_idx).set_flag(.option) // the return type of `fn ()?`
 pub const rvoid_type = new_type(void_type_idx).set_flag(.result) // the return type of `fn () !`
diff --git a/vlib/v/checker/check_types.v b/vlib/v/checker/check_types.v
index 9ec764ed76..8e6b963d90 100644
--- a/vlib/v/checker/check_types.v
+++ b/vlib/v/checker/check_types.v
@@ -575,7 +575,7 @@ fn (mut c Checker) check_shift(mut node ast.InfixExpr, left_type_ ast.Type, righ
 			// part of the quotient of E1/2^E2. If E1 has a signed type and
 			// a negative value, the resulting value is implementation-defined (ID).
 			left_sym_final := c.table.final_sym(left_type)
-			left_type_final := ast.Type(left_sym_final.idx)
+			left_type_final := ast.idx_to_type(left_sym_final.idx)
 			if !(c.is_generated || c.inside_unsafe || c.file.is_translated || c.pref.translated) {
 				if node.op == .left_shift && left_type_final.is_signed() {
 					c.note('shifting a value from a signed type `${left_sym_final.name}` can change the sign',
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 5851f6308a..4d662307f4 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -507,7 +507,7 @@ fn (mut c Checker) check_valid_pascal_case(name string, identifier string, pos t
 }
 
 fn (mut c Checker) type_decl(node ast.TypeDecl) {
-	if node.typ == ast.invalid_type_idx && (node is ast.AliasTypeDecl || node is ast.SumTypeDecl) {
+	if node.typ == ast.invalid_type && (node is ast.AliasTypeDecl || node is ast.SumTypeDecl) {
 		typ_desc := if node is ast.AliasTypeDecl { 'alias' } else { 'sum type' }
 		c.error('cannot register ${typ_desc} `${node.name}`, another type with this name exists',
 			node.pos)
@@ -852,7 +852,7 @@ fn (mut c Checker) fail_if_immutable(mut expr ast.Expr) (string, token.Pos) {
 				return to_lock, pos
 			}
 			left_sym := c.table.sym(expr.left_type)
-			mut elem_type := ast.Type(0)
+			mut elem_type := ast.no_type
 			mut kind := ''
 			match left_sym.info {
 				ast.Array {
@@ -1469,7 +1469,7 @@ fn (mut c Checker) selector_expr(mut node ast.SelectorExpr) ast.Type {
 			valid_generic := util.is_generic_type_name(name) && c.table.cur_fn != unsafe { nil }
 				&& name in c.table.cur_fn.generic_names
 			if valid_generic {
-				name_type = ast.Type(c.table.find_type_idx(name)).set_flag(.generic)
+				name_type = ast.idx_to_type(c.table.find_type_idx(name)).set_flag(.generic)
 			}
 		}
 		ast.TypeOf {
@@ -1813,7 +1813,7 @@ fn (mut c Checker) const_decl(mut node ast.ConstDecl) {
 
 fn (mut c Checker) enum_decl(mut node ast.EnumDecl) {
 	c.check_valid_pascal_case(node.name, 'enum name', node.pos)
-	if node.typ == ast.invalid_type_idx {
+	if node.typ == ast.invalid_type {
 		c.error('cannot register enum `${node.name}`, another type with this name exists',
 			node.pos)
 		return
diff --git a/vlib/v/checker/comptime.v b/vlib/v/checker/comptime.v
index 4bb83eabf9..161c4f8c14 100644
--- a/vlib/v/checker/comptime.v
+++ b/vlib/v/checker/comptime.v
@@ -265,7 +265,7 @@ fn (mut c Checker) comptime_for(mut node ast.ComptimeFor) {
 				c.push_new_comptime_info()
 				c.comptime.inside_comptime_for = true
 				if c.field_data_type == 0 {
-					c.field_data_type = ast.Type(c.table.find_type_idx('FieldData'))
+					c.field_data_type = ast.idx_to_type(c.table.find_type_idx('FieldData'))
 				}
 				c.comptime.comptime_for_field_value = field
 				c.comptime.comptime_for_field_var = node.val_var
@@ -298,7 +298,7 @@ fn (mut c Checker) comptime_for(mut node ast.ComptimeFor) {
 			c.push_new_comptime_info()
 			c.comptime.inside_comptime_for = true
 			if c.enum_data_type == 0 {
-				c.enum_data_type = ast.Type(c.table.find_type_idx('EnumData'))
+				c.enum_data_type = ast.idx_to_type(c.table.find_type_idx('EnumData'))
 			}
 			c.comptime.comptime_for_enum_var = node.val_var
 			c.comptime.type_map[node.val_var] = c.enum_data_type
@@ -327,7 +327,7 @@ fn (mut c Checker) comptime_for(mut node ast.ComptimeFor) {
 		}
 	} else if node.kind == .variants {
 		if c.variant_data_type == 0 {
-			c.variant_data_type = ast.Type(c.table.find_type_idx('VariantData'))
+			c.variant_data_type = ast.idx_to_type(c.table.find_type_idx('VariantData'))
 		}
 		mut variants := []ast.Type{}
 		if c.comptime.comptime_for_field_var != '' && typ == c.field_data_type {
diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 6f1c6dfcc2..9b2f3990e2 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -323,7 +323,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 			}
 		}
 	}
-	if node.return_type != ast.Type(0) {
+	if node.return_type != ast.no_type {
 		if !c.ensure_type_exists(node.return_type, node.return_type_pos) {
 			return
 		}
@@ -886,7 +886,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 		node.name = ''
 		c.expr(mut node.left)
 		left := node.left as ast.AnonFn
-		if left.typ != ast.Type(0) {
+		if left.typ != ast.no_type {
 			anon_fn_sym := c.table.sym(left.typ)
 			func = (anon_fn_sym.info as ast.FnType).func
 			found = true
@@ -1011,7 +1011,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 			return ast.void_type
 		}
 
-		ret_typ := ast.Type(idx).set_flag(.option)
+		ret_typ := ast.idx_to_type(idx).set_flag(.option)
 		if node.args.len != 1 {
 			c.error('expected 1 argument, but got ${node.args.len}', node.pos)
 		} else {
@@ -2103,7 +2103,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 				}
 				ast.Array {
 					typ := c.table.unaliased_type(final_left_sym.info.elem_type)
-					parent_type = ast.Type(c.table.find_or_register_array(typ))
+					parent_type = ast.idx_to_type(c.table.find_or_register_array(typ))
 				}
 				else {}
 			}
@@ -2357,7 +2357,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 		node.should_be_skipped = c.evaluate_once_comptime_if_attribute(mut method.attrs[method.ctdefine_idx])
 	}
 	c.check_expected_arg_count(mut node, method) or { return method.return_type }
-	mut exp_arg_typ := ast.Type(0) // type of 1st arg for special builtin methods
+	mut exp_arg_typ := ast.no_type // type of 1st arg for special builtin methods
 	mut param_is_mut := false
 	mut no_type_promotion := false
 	if left_sym.info is ast.Chan {
@@ -2371,7 +2371,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 	}
 
 	for i, mut arg in node.args {
-		if i > 0 || exp_arg_typ == ast.Type(0) {
+		if i > 0 || exp_arg_typ == ast.no_type {
 			exp_arg_typ = if method.is_variadic && i >= method.params.len - 1 {
 				method.params.last().typ
 			} else {
@@ -3021,7 +3021,7 @@ fn (mut c Checker) map_builtin_method_call(mut node ast.CallExpr, left_type_ ast
 			} else {
 				c.table.find_or_register_array(info.value_type)
 			}
-			ret_type = ast.Type(typ)
+			ret_type = ast.idx_to_type(typ)
 			if info.key_type.has_flag(.generic) && method_name == 'keys' {
 				ret_type = ret_type.set_flag(.generic)
 			}
diff --git a/vlib/v/checker/if.v b/vlib/v/checker/if.v
index 445e562a2a..ab487f41ef 100644
--- a/vlib/v/checker/if.v
+++ b/vlib/v/checker/if.v
@@ -570,15 +570,15 @@ fn (mut c Checker) smartcast_if_conds(mut node ast.Expr, mut scope ast.Scope) {
 						c.comptime.type_map['${c.comptime.comptime_for_variant_var}.typ']
 					} else {
 						c.error('invalid type `${right_expr}`', right_expr.pos)
-						ast.Type(0)
+						ast.no_type
 					}
 				}
 				else {
 					c.error('invalid type `${right_expr}`', right_expr.pos())
-					ast.Type(0)
+					ast.no_type
 				}
 			}
-			if right_type != ast.Type(0) {
+			if right_type != ast.no_type {
 				right_sym := c.table.sym(right_type)
 				mut expr_type := c.unwrap_generic(node.left_type)
 				left_sym := c.table.sym(expr_type)
diff --git a/vlib/v/checker/infix.v b/vlib/v/checker/infix.v
index 3a9b7f3615..272e565ac0 100644
--- a/vlib/v/checker/infix.v
+++ b/vlib/v/checker/infix.v
@@ -731,15 +731,15 @@ fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 						c.comptime.type_map['${c.comptime.comptime_for_variant_var}.typ']
 					} else {
 						c.error('invalid type `${right_expr}`', right_expr.pos)
-						ast.Type(0)
+						ast.no_type
 					}
 				}
 				else {
 					c.error('invalid type `${right_expr}`', right_expr.pos())
-					ast.Type(0)
+					ast.no_type
 				}
 			}
-			if typ != ast.Type(0) {
+			if typ != ast.no_type {
 				typ_sym := c.table.sym(typ)
 				op := node.op.str()
 				if typ_sym.kind == .placeholder {
diff --git a/vlib/v/checker/match.v b/vlib/v/checker/match.v
index 1a51be14b2..38c14f7b46 100644
--- a/vlib/v/checker/match.v
+++ b/vlib/v/checker/match.v
@@ -460,7 +460,7 @@ fn (mut c Checker) match_exprs(mut node ast.MatchExpr, cond_type_sym ast.TypeSym
 		// when match is type matching, then register smart cast for every branch
 		if expr_types.len > 0 {
 			if cond_type_sym.kind in [.sum_type, .interface_] {
-				mut expr_type := ast.Type(0)
+				mut expr_type := ast.no_type
 				if expr_types.len > 1 {
 					mut agg_name := strings.new_builder(20)
 					mut agg_cname := strings.new_builder(20)
diff --git a/vlib/v/checker/orm.v b/vlib/v/checker/orm.v
index 8967b6b42b..c8e81447bf 100644
--- a/vlib/v/checker/orm.v
+++ b/vlib/v/checker/orm.v
@@ -636,7 +636,7 @@ fn (mut c Checker) check_orm_or_expr(mut expr ORMExpr) {
 // check_db_expr checks the `db_expr` implements `orm.Connection` and has no `option` flag.
 fn (mut c Checker) check_db_expr(mut db_expr ast.Expr) bool {
 	connection_type_index := c.table.find_type_idx('orm.Connection')
-	connection_typ := ast.Type(connection_type_index)
+	connection_typ := ast.idx_to_type(connection_type_index)
 	db_expr_type := c.expr(mut db_expr)
 
 	// If we didn't find `orm.Connection`, we don't have any imported modules
@@ -678,7 +678,7 @@ fn (c &Checker) get_field_foreign_table_type(table_field &ast.StructField) ast.T
 	} else if c.table.sym(table_field.typ).kind == .array {
 		return c.table.sym(table_field.typ).array_info().elem_type
 	} else {
-		return ast.Type(0)
+		return ast.no_type
 	}
 }
 
diff --git a/vlib/v/checker/struct.v b/vlib/v/checker/struct.v
index 20a0546324..f8733fc099 100644
--- a/vlib/v/checker/struct.v
+++ b/vlib/v/checker/struct.v
@@ -633,8 +633,8 @@ fn (mut c Checker) struct_init(mut node ast.StructInit, is_field_zero_struct_ini
 						continue
 					}
 				}
-				mut got_type := ast.Type(0)
-				mut exp_type := ast.Type(0)
+				mut got_type := ast.no_type
+				mut exp_type := ast.no_type
 				inited_fields << field_name
 				exp_type = field_info.typ
 				exp_type_sym := c.table.sym(exp_type)
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index f89c3f632a..d83ee85973 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -1028,7 +1028,7 @@ pub fn (mut f Fmt) enum_decl(node ast.EnumDecl) {
 		f.write('pub ')
 	}
 	mut name := node.name.after('.')
-	if node.typ != ast.int_type && node.typ != ast.invalid_type_idx {
+	if node.typ != ast.int_type && node.typ != ast.invalid_type {
 		senum_type := f.table.type_to_str_using_aliases(node.typ, f.mod2alias)
 		name += ' as ${senum_type}'
 	}
diff --git a/vlib/v/gen/c/assign.v b/vlib/v/gen/c/assign.v
index 9037df5fe5..3f209d7576 100644
--- a/vlib/v/gen/c/assign.v
+++ b/vlib/v/gen/c/assign.v
@@ -485,8 +485,8 @@ fn (mut g Gen) assign_stmt(node_ ast.AssignStmt) {
 			}
 			mut str_add := false
 			mut op_overloaded := false
-			mut op_expected_left := ast.Type(0)
-			mut op_expected_right := ast.Type(0)
+			mut op_expected_left := ast.no_type
+			mut op_expected_right := ast.no_type
 			is_shared_re_assign := !is_decl && node.left_types[i].has_flag(.shared_f)
 				&& left is ast.Ident && left_sym.kind in [.array, .map, .struct_]
 			if node.op == .plus_assign && unaliased_right_sym.kind == .string {
diff --git a/vlib/v/gen/c/auto_str_methods.v b/vlib/v/gen/c/auto_str_methods.v
index 9a189f798a..21ec93528d 100644
--- a/vlib/v/gen/c/auto_str_methods.v
+++ b/vlib/v/gen/c/auto_str_methods.v
@@ -1255,9 +1255,9 @@ fn (mut g Gen) get_enum_type_idx_from_fn_name(fn_name string) (string, int) {
 }
 
 fn (mut g Gen) gen_enum_static_from_string(fn_name string, mod_enum_name string, idx int) {
-	enum_typ := ast.Type(idx)
+	enum_typ := ast.idx_to_type(idx)
 	enum_styp := g.typ(enum_typ)
-	option_enum_typ := ast.Type(idx).set_flag(.option)
+	option_enum_typ := enum_typ.set_flag(.option)
 	option_enum_styp := g.typ(option_enum_typ)
 	enum_field_names := g.table.get_enum_field_names(mod_enum_name)
 	enum_field_vals := g.table.get_enum_field_vals(mod_enum_name)
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index e61c9241a8..779f3bd1cc 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -325,9 +325,9 @@ pub fn gen(files []&ast.File, mut table ast.Table, pref_ &pref.Preferences) (str
 			label:        'global_cgen'
 		)
 		inner_loop:           unsafe { &ast.empty_stmt }
-		field_data_type:      ast.Type(table.find_type_idx('FieldData'))
-		enum_data_type:       ast.Type(table.find_type_idx('EnumData'))
-		variant_data_type:    ast.Type(table.find_type_idx('VariantData'))
+		field_data_type:      ast.idx_to_type(table.find_type_idx('FieldData'))
+		enum_data_type:       ast.idx_to_type(table.find_type_idx('EnumData'))
+		variant_data_type:    ast.idx_to_type(table.find_type_idx('VariantData'))
 		is_cc_msvc:           pref_.ccompiler == 'msvc'
 		use_segfault_handler: !('no_segfault_handler' in pref_.compile_defines
 			|| pref_.os in [.wasm32, .wasm32_emscripten])
@@ -715,8 +715,8 @@ fn cgen_process_one_file_cb(mut p pool.PoolProcessor, idx int, wid int) &Gen {
 			label:        'cgen_process_one_file_cb idx: ${idx}, wid: ${wid}'
 		)
 		inner_loop:           &ast.empty_stmt
-		field_data_type:      ast.Type(global_g.table.find_type_idx('FieldData'))
-		enum_data_type:       ast.Type(global_g.table.find_type_idx('EnumData'))
+		field_data_type:      ast.idx_to_type(global_g.table.find_type_idx('FieldData'))
+		enum_data_type:       ast.idx_to_type(global_g.table.find_type_idx('EnumData'))
 		array_sort_fn:        global_g.array_sort_fn
 		waiter_fns:           global_g.waiter_fns
 		threaded_fns:         global_g.threaded_fns
@@ -1175,7 +1175,7 @@ fn (mut g Gen) option_type_name(t ast.Type) (string, string) {
 	} else {
 		styp = '${c.option_name}_${base}'
 	}
-	if t.is_ptr() || t.has_flag(.generic) {
+	if t.has_flag(.generic) || t.is_ptr() {
 		styp = styp.replace('*', '_ptr')
 	}
 	return styp, base
@@ -1197,7 +1197,7 @@ fn (mut g Gen) result_type_name(t ast.Type) (string, string) {
 	} else {
 		styp = '${c.result_name}_${base}'
 	}
-	if t.is_ptr() || t.has_flag(.generic) {
+	if t.has_flag(.generic) || t.is_ptr() {
 		styp = styp.replace('*', '_ptr')
 	}
 	return styp, base
@@ -2426,13 +2426,13 @@ fn (mut g Gen) get_sumtype_casting_fn(got_ ast.Type, exp_ ast.Type) string {
 	g.sumtype_casting_fns << SumtypeCastingFn{
 		fn_name: fn_name
 		got:     if got_.has_flag(.option) {
-			new_got := ast.Type(got_sym.idx).set_flag(.option)
+			new_got := ast.idx_to_type(got_sym.idx).set_flag(.option)
 			new_got
 		} else {
 			got_sym.idx
 		}
 		exp: if exp_.has_flag(.option) {
-			new_exp := ast.Type(exp).set_flag(.option)
+			new_exp := ast.idx_to_type(exp).set_flag(.option)
 			new_exp
 		} else {
 			exp
diff --git a/vlib/v/gen/c/dumpexpr.v b/vlib/v/gen/c/dumpexpr.v
index 8d629c0f87..fb3f1d5b14 100644
--- a/vlib/v/gen/c/dumpexpr.v
+++ b/vlib/v/gen/c/dumpexpr.v
@@ -102,7 +102,7 @@ fn (mut g Gen) dump_expr_definitions() {
 			name = name[3..]
 		}
 		_, str_method_expects_ptr, _ := dump_sym.str_method_info()
-		typ := ast.Type(dump_type)
+		typ := ast.idx_to_type(dump_type)
 		is_ptr := typ.is_ptr()
 		deref, _ := deref_kind(str_method_expects_ptr, is_ptr, dump_type)
 		to_string_fn_name := g.get_str_fn(typ.clear_flags(.shared_f, .result))
diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index b6a5797f14..7fd7edc667 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -1543,7 +1543,7 @@ fn (mut g Gen) resolve_receiver_type(node ast.CallExpr) (ast.Type, &ast.TypeSymb
 		typ := g.table.unaliased_type(typ_sym.info.elem_type)
 		typ_idx := g.table.find_type_idx(g.table.array_name(typ))
 		if typ_idx > 0 {
-			unwrapped_rec_type = ast.Type(typ_idx)
+			unwrapped_rec_type = ast.idx_to_type(typ_idx)
 			typ_sym = g.table.sym(unwrapped_rec_type)
 		}
 	}
@@ -1927,7 +1927,7 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 	mut is_interface_call := false
 	mut is_selector_call := false
 	if node.left_type != 0 {
-		mut fn_typ := ast.Type(0)
+		mut fn_typ := ast.no_type
 		left_sym := g.table.sym(node.left_type)
 		if node.is_field {
 			if field := g.table.find_field_with_embeds(left_sym, node.name) {
diff --git a/vlib/v/gen/c/infix.v b/vlib/v/gen/c/infix.v
index e12dbf9a1c..b7a759d229 100644
--- a/vlib/v/gen/c/infix.v
+++ b/vlib/v/gen/c/infix.v
@@ -717,10 +717,10 @@ fn (mut g Gen) infix_expr_is_op(node ast.InfixExpr) {
 				g.unwrap_generic(node.right.typ)
 			}
 			ast.None {
-				g.table.type_idxs['None__']
+				ast.idx_to_type(g.table.type_idxs['None__'])
 			}
 			else {
-				ast.Type(0)
+				ast.no_type
 			}
 		}
 		sub_sym := g.table.sym(sub_type)
diff --git a/vlib/v/gen/c/json.v b/vlib/v/gen/c/json.v
index a367728153..0e1ba421ab 100644
--- a/vlib/v/gen/c/json.v
+++ b/vlib/v/gen/c/json.v
@@ -562,7 +562,7 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 						'cJSON_IsString(root->child)'
 					} else if var_t.ends_with('bool') {
 						'cJSON_IsBool(root->child)'
-					} else if g.table.sym(g.table.value_type(ast.Type(variant_symbols[i].idx))).kind == .struct_ {
+					} else if g.table.sym(g.table.value_type(ast.idx_to_type(variant_symbols[i].idx))).kind == .struct_ {
 						'cJSON_IsObject(root->child)'
 					} else {
 						'cJSON_IsNumber(root->child)'
diff --git a/vlib/v/gen/js/comptime.v b/vlib/v/gen/js/comptime.v
index 76a32cb989..87ecb13bd4 100644
--- a/vlib/v/gen/js/comptime.v
+++ b/vlib/v/gen/js/comptime.v
@@ -90,7 +90,7 @@ fn (mut g JsGen) comptime_if_cond(cond ast.Expr, pkg_exist bool) bool {
 				.key_is, .not_is {
 					left := cond.left
 					mut name := ''
-					mut exp_type := ast.Type(0)
+					mut exp_type := ast.no_type
 					got_type := (cond.right as ast.TypeNode).typ
 					// Handle `$if x is Interface {`
 					// mut matches_interface := 'false'
diff --git a/vlib/v/gen/js/js.v b/vlib/v/gen/js/js.v
index 90e6e7da32..d8bac5a10e 100644
--- a/vlib/v/gen/js/js.v
+++ b/vlib/v/gen/js/js.v
@@ -3189,7 +3189,7 @@ fn (mut g JsGen) greater_typ(left ast.Type, right ast.Type) ast.Type {
 		}
 		return ast.Type(ast.int_literal_type_idx)
 	}
-	return ast.Type(l)
+	return ast.idx_to_type(l)
 }
 
 fn (mut g JsGen) gen_map_init_expr(it ast.MapInit) {
diff --git a/vlib/v/markused/markused.v b/vlib/v/markused/markused.v
index 07b4465473..35e3859222 100644
--- a/vlib/v/markused/markused.v
+++ b/vlib/v/markused/markused.v
@@ -447,7 +447,7 @@ fn handle_vweb(mut table ast.Table, mut all_fn_root_names []string, result_name
 	result_type_idx := table.find_type_idx(result_name)
 	if result_type_idx != 0 {
 		all_fn_root_names << filter_name
-		typ_vweb_context := ast.Type(table.find_type_idx(context_name)).set_nr_muls(1)
+		typ_vweb_context := ast.idx_to_type(table.find_type_idx(context_name)).set_nr_muls(1)
 		all_fn_root_names << '${int(typ_vweb_context)}.html'
 		for vgt in table.used_vweb_types {
 			sym_app := table.sym(vgt)
diff --git a/vlib/v/parser/orm.v b/vlib/v/parser/orm.v
index f6e8a31478..db542db4db 100644
--- a/vlib/v/parser/orm.v
+++ b/vlib/v/parser/orm.v
@@ -246,7 +246,7 @@ fn (mut p Parser) parse_sql_stmt_line() ast.SqlStmtLine {
 		}
 	}
 	mut inserted_var := ''
-	mut table_type := ast.Type(0)
+	mut table_type := ast.no_type
 	if kind != .delete {
 		if kind == .update {
 			table_type = p.parse_type()
diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
index 3883f126fc..850313a241 100644
--- a/vlib/v/parser/parse_type.v
+++ b/vlib/v/parser/parse_type.v
@@ -335,7 +335,7 @@ fn (mut p Parser) parse_fn_type(name string, generic_types []ast.Type) ast.Type
 	}
 
 	generic_names := p.types_to_names(generic_types, fn_type_pos, 'generic_types') or {
-		return ast.Type(0)
+		return ast.no_type
 	}
 
 	func := ast.Fn{
@@ -425,7 +425,7 @@ fn (mut p Parser) parse_inline_sum_type() ast.Type {
 		for variant in variants {
 			if variant.typ == 0 {
 				p.error_with_pos('unknown type for variant: ${variant}', variant.pos)
-				return ast.Type(0)
+				return ast.no_type
 			}
 			variant_names << p.table.sym(variant.typ).name
 		}
@@ -452,7 +452,7 @@ fn (mut p Parser) parse_inline_sum_type() ast.Type {
 	} else if variants.len == 1 {
 		return variants[0].typ
 	}
-	return ast.Type(0)
+	return ast.no_type
 }
 
 // parse_sum_type_variants parses several types separated with a pipe and returns them as a list with at least one node.
@@ -714,7 +714,7 @@ fn (mut p Parser) parse_any_type(language ast.Language, is_ptr bool, check_dot b
 			if name == 'thread' {
 				return p.parse_thread_type()
 			}
-			mut ret := ast.Type(0)
+			mut ret := ast.no_type
 			if name == '' {
 				// This means the developer is using some wrong syntax like `x: int` instead of `x int`
 				p.error('expecting type declaration')
@@ -806,7 +806,7 @@ fn (mut p Parser) find_type_or_add_placeholder(name string, language ast.Languag
 				if p.struct_init_generic_types.len > 0 && sym.info.generic_types.len > 0
 					&& p.struct_init_generic_types != sym.info.generic_types {
 					generic_names := p.types_to_names(p.struct_init_generic_types, p.tok.pos(),
-						'struct_init_generic_types') or { return ast.Type(0) }
+						'struct_init_generic_types') or { return ast.no_type }
 					// NOTE:
 					// Used here for the wraparound `< >` characters, is not a reserved character in generic syntax,
 					// is used as the `generic names` part of the qualified type name,
diff --git a/vlib/v/parser/struct.v b/vlib/v/parser/struct.v
index d2aa06d4cd..889fc16d10 100644
--- a/vlib/v/parser/struct.v
+++ b/vlib/v/parser/struct.v
@@ -178,7 +178,7 @@ fn (mut p Parser) struct_decl(is_anon bool) ast.StructDecl {
 			is_on_top := ast_fields.len == 0 && !(is_field_pub || is_field_mut || is_field_global)
 			has_prev_newline := p.has_prev_newline()
 			mut field_name := ''
-			mut typ := ast.Type(0)
+			mut typ := ast.no_type
 			mut type_pos := token.Pos{}
 			mut field_pos := token.Pos{}
 			mut option_pos := token.Pos{}