@psalm-mutation-free
The @psalm-mutation-free tag declares that a method never mutates any state, whether observable from outside the object or purely internal to it.
"@psalm-mutation-free" [ <Description> ]
Parsing a @psalm-mutation-free tag produces a PsalmMutationFreeTag instance. Being a pure marker, it adds nothing beyond the $name and optional $description every Tag already carries.
final class PsalmMutationFreeTag extends FlagTag {}
Defined by Psalm's supported annotations reference.
08 July 2026