[12.x] Allow any \Stringable implementation for Illuminate\Support\Stringable::exactly()

src/Illuminate/Support/Stringable.php

@@ -293,13 +293,13 @@ public function doesntEndWith($needles)
     /**
      * Determine if the string is an exact match with the given value.
      *
-     * @param  \Illuminate\Support\Stringable|string  $value
+     * @param  BaseStringable|string  $value
      * @return bool
      */
     public function exactly($value)
     {
-        if ($value instanceof Stringable) {
-            $value = $value->toString();
+        if ($value instanceof BaseStringable) {
+            $value = (string) $value;
         }
 
         return $this->value === $value;

tests/Support/SupportStringableTest.php

@@ -1477,6 +1477,14 @@ public function testExactly()
         $this->assertFalse($this->stringable('Foo')->exactly('foo'));
         $this->assertFalse($this->stringable('[]')->exactly([]));
         $this->assertFalse($this->stringable('0')->exactly(0));
+        $this->assertTrue($this->stringable('foo')->exactly(new class() implements \Stringable
+        {
+            public function __toString(): string
+            {
+                return 'foo';
+            }
+        }));
+        $this->assertFalse($this->stringable('foo')->exactly(new class() {}));
     }
 
     public function testToInteger()