diff --git a/vlib/v/ast/types.v b/vlib/v/ast/types.v
index e97fdde1e1..c1617cd4c6 100644
--- a/vlib/v/ast/types.v
+++ b/vlib/v/ast/types.v
@@ -150,6 +150,8 @@ pub fn (t Type) nr_muls() int {
 // return true if `t` is a pointer (nr_muls>0)
 [inline]
 pub fn (t Type) is_ptr() bool {
+	// any normal pointer, i.e. &Type, &&Type etc;
+	// NB: voidptr, charptr and byteptr are NOT included!
 	return (int(t) >> 16) & 0xff > 0
 }
 
@@ -270,9 +272,9 @@ pub fn new_type_ptr(idx int, nr_muls int) Type {
 	return (nr_muls << 16) | u16(idx)
 }
 
-// built in pointers (voidptr, byteptr, charptr)
 [inline]
 pub fn (typ Type) is_pointer() bool {
+	// builtin pointer types (voidptr, byteptr, charptr)
 	return typ.idx() in ast.pointer_type_idxs
 }
 
@@ -286,6 +288,26 @@ pub fn (typ Type) is_int() bool {
 	return typ.clear_flags() in ast.integer_type_idxs
 }
 
+[inline]
+pub fn (typ Type) is_int_valptr() bool {
+	return typ.idx() in ast.integer_type_idxs
+}
+
+[inline]
+pub fn (typ Type) is_float_valptr() bool {
+	return typ.idx() in ast.float_type_idxs
+}
+
+[inline]
+pub fn (typ Type) is_pure_int() bool {
+	return int(typ) in ast.integer_type_idxs
+}
+
+[inline]
+pub fn (typ Type) is_pure_float() bool {
+	return int(typ) in ast.float_type_idxs
+}
+
 [inline]
 pub fn (typ Type) is_signed() bool {
 	return typ.idx() in ast.signed_integer_type_idxs
diff --git a/vlib/v/gen/c/auto_str_methods.v b/vlib/v/gen/c/auto_str_methods.v
index 9c362cf3eb..da6e31a999 100644
--- a/vlib/v/gen/c/auto_str_methods.v
+++ b/vlib/v/gen/c/auto_str_methods.v
@@ -42,7 +42,7 @@ fn (mut g Gen) gen_str_default(sym ast.TypeSymbol, styp string, str_fn_name stri
 
 fn (g &Gen) type_to_fmt(typ ast.Type) string {
 	sym := g.table.get_type_symbol(typ)
-	if typ.is_ptr() && (typ.is_int() || typ.is_float()) {
+	if typ.is_ptr() && (typ.is_int_valptr() || typ.is_float_valptr()) {
 		return '%.*s\\000'
 	} else if sym.kind in [.struct_, .array, .array_fixed, .map, .bool, .enum_, .interface_,
 		.sum_type, .function, .alias] {
@@ -512,7 +512,8 @@ fn (mut g Gen) gen_str_for_struct(info ast.Struct, styp string, str_fn_name stri
 					g.auto_str_funcs.write_string('isnil(it.${c_name(field.name)})')
 					g.auto_str_funcs.write_string(' ? _SLIT("nil") : ')
 					// struct, floats and ints have a special case through the _str function
-					if sym.kind != .struct_ && !field.typ.is_int() && !field.typ.is_float() {
+					if sym.kind != .struct_ && !field.typ.is_int_valptr()
+						&& !field.typ.is_float_valptr() {
 						g.auto_str_funcs.write_string('*')
 					}
 				}
@@ -558,8 +559,8 @@ fn struct_auto_str_func(sym &ast.TypeSymbol, field_type ast.Type, fn_name string
 		mut method_str := 'it.${c_name(field_name)}'
 		if sym.kind == .bool {
 			method_str += ' ? _SLIT("true") : _SLIT("false")'
-		} else if (field_type.is_int() || field_type.is_float()) && field_type.is_ptr()
-			&& !expects_ptr {
+		} else if (field_type.is_int_valptr() || field_type.is_float_valptr())
+			&& field_type.is_ptr() && !expects_ptr {
 			// ptr int can be "nil", so this needs to be castet to a string
 			fmt := if sym.kind in [.f32, .f64] {
 				'%g\\000'