Enum abstract not checked

[Nicolas Cannasse]

Surprisingly the following compile while it shouldn't ( T should be Int on step++)

enum abstract T(Int) {
   var Start;
   var End;
}

class Test {
  
  static var step(default,set) : T;
  
  static function set_step(s:T) { step = s; return s; }
  
  static function main() {
     step++;
  }
}

[Simon Krajewski]

It's even worse:

class Main {
	static var step(default, set):String;

	static function set_step(s:String) {
		step = s;
		return s;
	}

	static function main() {
		step++;
	}
}

(Edit: Well that would actually make some sense with String and + specifically, but it admits any type here it seems.)

[Nicolas Cannasse]

Is it a regression ? It seems quite bad, we want the fix to be merged asap @yuxiaomao :D

[Simon Krajewski]

According to my brief try.haxe investigations it was a regression from 4.1 to 4.2, so quite old.

I'll pull the linked fix and will keep this issue open as a reminder to add tests.

[Yuxiao Mao]

The case of string++ can still compile without warning. Is that normal?

[Simon Krajewski]

Good question... when accessors are involved, a++ is pretty much treated like a += 1 and this has always been admitted for operands of type String and Int. But it doesn't really look like it should work.