use the new &C.Foo(0) cast

vlib/compiler/gen_c.v

@@ -488,6 +488,7 @@ fn (p mut Parser) gen_struct_init(typ string, t Type) bool {
 		// TODO tmp hack for 0 pointers init
 		// &User{!} ==> 0
 		if p.tok == .not {
+			p.warn('use `$t.name(0)` instead of `&$t.name{!}`')
 			p.next()
 			p.gen('0')
 			p.check(.rcbr)

vlib/os/os_nix.v

@@ -31,8 +31,8 @@ pub fn ls(path string) ?[]string {
 	if isnil(dir) {
 		return error('ls() couldnt open dir "$path"')
 	}
-	//mut ent := &C.dirent(0)
-	mut ent := &C.dirent{!}
+	mut ent := &C.dirent(0)
+	//mut ent := &C.dirent{!}
 	for {
 		ent = C.readdir(dir)
 		if isnil(ent) {

vlib/time/time.v

@@ -102,7 +102,7 @@ fn C.time(int) C.time_t
 
 pub fn now() Time {
 	t := C.time(0)
-	mut now := &C.tm{!}
+	mut now := &C.tm(0)
 	now = C.localtime(&t)
 	return convert_ctime(now)
 }