added implementation of __toString() method

src/Enum.php

@@ -123,6 +123,14 @@ abstract class Enum
 		return $this->scalarValue;
 	}
 
+	public function __toString(): string
+	{
+		// as enum does not allow mixed key types (all must be int or all string),
+		// we can safely convert integers to strings without worrying introducing
+		// value conflicts
+		return (string) $this->toScalar();
+	}
+
 	/**
 	 * Retrieves constant name that is used to access enum value.
 	 *

tests/Basic/accessing-scalar-value.phpt

+<?php
+declare(strict_types=1);
+
+require __DIR__ . '/../bootstrap.php';
+
+/**
+ * @method static EnumString VALUE1()
+ * @method static EnumString VALUE2()
+ */
+class EnumString extends \Grifart\Enum\Enum
+{
+	use Grifart\Enum\AutoInstances;
+
+	protected const VALUE1 = 'value1';
+	protected const VALUE2 = 'value2';
+}
+
+\Tester\Assert::same('value1', EnumString::VALUE1()->toScalar());
+\Tester\Assert::same('value1', (string) EnumString::VALUE1());
+
+\Tester\Assert::same('value2', EnumString::VALUE2()->toScalar());
+\Tester\Assert::same('value2', (string) EnumString::VALUE2());
+
+
+/**
+ * @method static EnumInt VALUE1()
+ * @method static EnumInt VALUE2()
+ */
+class EnumInt extends \Grifart\Enum\Enum
+{
+	use Grifart\Enum\AutoInstances;
+
+	protected const VALUE1 = 1;
+	protected const VALUE2 = 2;
+}
+
+\Tester\Assert::same(1, EnumInt::VALUE1()->toScalar());
+\Tester\Assert::same('1', (string) EnumInt::VALUE1());
+
+\Tester\Assert::same(2, EnumInt::VALUE2()->toScalar());
+\Tester\Assert::same('2', (string) EnumInt::VALUE2());