PHP RFC: Debugable Enums

• Version: 0.2
• Date: 2026-03-12
• Author: Daniel Scherzer, daniel.e.scherzer@gmail.com
• Status: Under Discussion
• Implementation: https://github.com/php/php-src/pull/21425
• Discussion thread:

Enumerations (enums) were introduced in PHP 8.1 (enumerations). The RFC specified that magic methods other than __call(), __callStatic(), and __invoke() would not be permitted in enums, noting that most other magic methods involve state, which enum instances do not have. However, the exclusion also applies to __debugInfo(), which does not need to involve state. This RFC proposes allowing the __debugInfo() magic method on enums.

<?php
 
enum Foo: string {
	case Bar = "Baz";
 
	public function __debugInfo() {
		return [ __CLASS__ . '::' . $this->name . ' = ' . $this->value ];
	}
}
 
var_dump(Foo::Bar); // produces an array with `"Foo::Bar = Baz"`
 
?>

The error when trying to implement __debugInfo() on an enumeration is removed. The default validation of that magic method (visibility, arguments, return type) is applied if the method is present.

Simple example for a unit enum:

<?php
 
enum Foo {
	case Bar;
 
	public function __debugInfo() {
		return [$this->name . ' is a case of the ' . __CLASS__ . ' enum'];
	}
}
 
var_dump(Foo::Bar); // produces an array with "Bar is a case of the Foo enum"
 
?>

Simple example for a backed enum:

<?php
 
enum Foo: string {
	case Bar = "Baz";
 
	public function __debugInfo() {
		return [__CLASS__ . '::' . $this->name . ' = ' . $this->value];
	}
}
 
var_dump(Foo::Bar); // produces an array with `"Foo::Bar = Baz"`
 
?>

There should be no backward incompatible changes - this is the removal of an existing error.

Next PHP version (PHP 8.6).

Analysis tools that warn about trying to define a __debugInfo() method on enums would need to be updated to not warn when the code is for PHP 8.6+.

There are some built-in enums, e.g. \Random\IntervalBoundary - in the future, they may have __debugInfo() methods, but this RFC does not include such additions.

Perhaps some of the other magic methods should also be allowed.

Please consult the php/policies repository for the current voting guidelines.

https://github.com/php/php-src/pull/21425

After the RFC is implemented, this section should contain:

1. the version(s) it was merged into
2. a link to the git commit(s)
3. a link to the PHP manual entry for the feature

Links to external references, discussions, or RFCs.

• Originally, an RFC proposed allowing __toString() on enums, rather than __debugInfo(), but feedback on the mailing list (https://news-web.php.net/php.internals/129540) led to a rewrite.

If there are major changes to the initial proposal, please include a short summary with a date or a link to the mailing list announcement here, as not everyone has access to the wikis' version history.