===description===
implicitCastToUnion
===file===
<?php
                    class A {
                        public function __toString(): string
                        {
                            return "hello";
                        }
                    }

                    /** 
                     * @param string|int $b
                     * @psalm-mutation-free 
                     */
                    function fooFoo($b): void {}
                    fooFoo(new A());
===expect===
ImplicitToStringCast
===ignore===
TODO
