Fix issue reconciling class strings

src/Psalm/Type/Atomic/TLiteralClassString.php

@@ -16,6 +16,14 @@ class TLiteralClassString extends TLiteralString
         return 'class-string';
     }
 
+    /**
+     * @return string
+     */
+    public function getKey()
+    {
+        return 'class-string(' . $this->value . ')';
+    }
+
     /**
      * @param  string|null   $namespace
      * @param  array<string> $aliased_classes

tests/ClassStringTest.php

@@ -246,6 +246,20 @@ class ClassStringTest extends TestCase
                         bar($class);
                     }',
             ],
+            'arrayEquivalence' => [
+                '<?php
+                    class A {}
+                    class B {}
+
+                    $foo = [
+                        A::class,
+                        B::class
+                    ];
+
+                    foreach ($foo as $class) {
+                        if ($class === A::class) {}
+                    }',
+            ],
         ];
     }