Type::Tiny::ConstrainedObject(3) User Contributed Perl Documentation Type::Tiny::ConstrainedObject(3)

# [NAME](#NAME)

Type::Tiny::ConstrainedObject - shared behaviour for Type::Tiny::Class, etc

# [STATUS](#STATUS)

This module is considered experiemental.

# [DESCRIPTION](#DESCRIPTION)

## [Methods](#Methods)

The following methods exist for Type::Tiny::Class, Type::Tiny::Role, Type::Tiny::Duck, and any type constraints that inherit from "Object" or "Overload" in Types::Standard.

These methods will also work for Type::Tiny::Intersection if at least one of the types in the intersection provides these methods.

These methods will also work for Type::Tiny::Union if all of the types in the union provide these methods.

[stringifies\_to($constraint)](#stringifies_to%28$constraint%29)

Generates a new child type constraint which checks the object's stringification against a constraint. For example:

```
   my $type  = Type::Tiny::Class->new(class => 'URI');
   my $child = $type->stringifies_to( StrMatch[qr/^http:/] );
   
   $child->assert_valid( URI->new("http://example.com/") );
    
```

In the above example, $child is a type constraint that checks objects are blessed into (or inherit from) the URI class, and when stringified (e.g. though overloading) the result matches the regular expression "qr/^http:/".

$constraint may be a type constraint, something that can be coerced to a type constraint (such as a coderef returning a boolean), a string of Perl code operating on $\_, or a reference to a regular expression.

So the following would work:

```
   my $child = $type->stringifies_to( sub { qr/^http:/ } );
   my $child = $type->stringifies_to(       qr/^http:/   );
   my $child = $type->stringifies_to(       'm/^http:/'  );
   
   my $child = $type->where('"$_" =~ /^http:/');
    
```

[numifies\_to($constraint)](#numifies_to%28$constraint%29)

The same as "stringifies\_to" but checks numification.

The following might be useful:

```
   use Types::Standard qw(Int Overload);
   my $IntLike = Int | Overload->numifies_to(Int)
    
```

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

This is best explained with an example:

```
   use Types::Common qw( InstanceOf StrMatch IntRange );
   
   my $person = InstanceOf['Local::Human'];
   my $woman  = $person->with_attribute_values(
      gender   => StrMatch[ qr/^F/i  ],
      age      => IntRange[ 18 => () ],
   );
   
   $woman->assert_valid($alice);
    
```

This assertion will firstly check that $alice is a Local::Human, then check that "$alice->gender" starts with an "F", and lastly check that "$alice->age" is an integer at least 18.

Again, constraints can be type constraints, coderefs, strings of Perl code, or regular expressions.

Technically the "attributes" don't need to be Moo/Moose/Mouse attributes, but any methods which can be called with no parameters and return a scalar.

# [BUGS](#BUGS)

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

# [SEE ALSO](#SEE_ALSO)

Type::Tiny::Manual.

Type::Tiny.

# [AUTHOR](#AUTHOR)

Toby Inkster <tobyink@cpan.org>.

# [COPYRIGHT AND LICENCE](#COPYRIGHT_AND_LICENCE)

This software is copyright (c) 2019-2025 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](#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.

2026-10-25 perl v5.44.0

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Document: Type::Tiny::ConstrainedObject(3pm) from perl-type-tiny 2.010001-r4 (Chainguard OS)
Source: https://github.com/tobyink/p5-type-tiny