---
name: "Type::Tiny::Union"
section: "3pm"
platform: "linux"
package: "perl-type-tiny"
version: "2.010001-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Type::Tiny::Union"
---

# Type::Tiny::Union(3pm)

union type constraints

## NAME

Type::Tiny::Union - union type constraints

## SYNOPSIS

Using via the `"|"` operator overload:

```
  package Local::Stash {
    use Moo;
    use Types::Common qw( ArrayRef HashRef );

    has data => (
      is   => 'ro',
      isa  => HashRef | ArrayRef,
    );
  }

  my $x = Local::Stash->new( data => {} );  # ok
  my $y = Local::Stash->new( data => [] );  # ok
```

Using Type::Tiny::Union's object-oriented interface:

```
  package Local::Stash {
    use Moo;
    use Types::Common qw( ArrayRef HashRef );
    use Type::Tiny::Union;

    my $AnyData = Type::Tiny::Union->new(
      name             => 'AnyData',
      type_constraints => [ HashRef, ArrayRef ],
    );

    has data => (
      is   => 'ro',
      isa  => $AnyData,
    );
  }
```

Using Type::Utils's functional interface:

```
  package Local::Stash {
    use Moo;
    use Types::Common qw( ArrayRef HashRef );
    use Type::Utils;

    my $AnyData = union AnyData => [ HashRef, ArrayRef ];

    has data => (
      is   => 'ro',
      isa  => $AnyData,
    );
  }
```

## STATUS

This module is covered by the Type-Tiny stability policy.

## DESCRIPTION

Union type constraints.

This package inherits from Type::Tiny; see that for most documentation. Major differences are listed below:

### Constructor

The `"new"` constructor from Type::Tiny still works, of course. But there is also:

- new\_by\_overload(%attributes)

  Like the `"new"` constructor, but will sometimes return another type constraint which is not strictly an instance of Type::Tiny::Union, but still encapsulates the same meaning. This constructor is used by Type::Tiny's overloading of the `"|"` operator.

### Attributes

- "type\_constraints"

  Arrayref of type constraints.

  When passed to the constructor, if any of the type constraints in the union is itself a union type constraint, this is "exploded" into the new union.

- "constraint"

  Unlike Type::Tiny, you *cannot* pass a constraint coderef to the constructor. Instead rely on the default.

- "inlined"

  Unlike Type::Tiny, you *cannot* pass an inlining coderef to the constructor. Instead rely on the default.

- "parent"

  Unlike Type::Tiny, you *cannot* pass an inlining coderef to the constructor. A parent will instead be automatically calculated.

- "coercion"

  You probably do not pass this to the constructor. (It's not currently disallowed, as there may be a use for it that I haven't thought of.)

  The auto-generated default will be a Type::Coercion::Union object.

### Methods

- find\_type\_for($value)

  Returns the first individual type constraint in the union which `$value` passes.

- stringifies\_to($constraint)

  See Type::Tiny::ConstrainedObject.

- numifies\_to($constraint)

  See Type::Tiny::ConstrainedObject.

- "with\_attribute\_values($attr1 =\> $constraint1, ...)"

  See Type::Tiny::ConstrainedObject.

### Overloading

- •

  Arrayrefification calls `"type_constraints"`.

## BUGS

Please report any bugs to \<https://github.com/tobyink/p5-type-tiny/issues\>.

## SEE ALSO

Type::Tiny::Manual.

Type::Tiny.

## AUTHOR

Toby Inkster \<tobyink@cpan.org\>.

## COPYRIGHT AND LICENCE

This software is copyright (c) 2013-2014, 2017-2025 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

## DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.