Test.hx

class Test {


    static function main() {
        var f:Escaped = '<div>foo</div>';
        var k:Foo = {k:'<div>blah!</div>'};
        trace(f); // not escaped, simple trace
        trace(k); // not escaped, simple trace
        trace(f + ' some other string'); //  escaped!
        trace(k.k + ' extra');  // escaped as field access!
        trace(k + " extra");  // escaped as autocasted concatenation!
        trace(f.raw() + ' extra'); // unescaped concatenation

    }
    static function test(x:String){
        trace(x);
    }

}

abstract Escaped(String) {
    public inline function new(s:String){
        this = s;
    }
    public inline function raw(){
        return this;
    }
    @:from static inline function fromString(s){
        return new Escaped(s);
    }
    @:to static function toString(s){
        return StringTools.htmlEscape(s) ;
    }
}
typedef Foo = {
    k:Escaped
}