=pod =head1 PURPOSE OK, we need to bite the bullet and lock down coercions on core type constraints and parameterized type constraints. =head1 SEE ALSO L. =head1 AUTHOR Toby Inkster Etobyink@cpan.orgE. =head1 COPYRIGHT AND LICENCE This software is copyright (c) 2014, 2017-2022 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. =cut use strict; use warnings; use Test::More; use Test::Fatal; use Types::Standard -types; use Types::Common::Numeric -types; my $frozen = qr/\AAttempt to add coercion code to a Type::Coercion/; like( exception { Str->coercion->add_type_coercions(ArrayRef, sub { "@$_" }); }, $frozen, 'Types::Standard core types are frozen', ); like( exception { PositiveInt->coercion->add_type_coercions(NegativeInt, sub { -$_ }); }, $frozen, 'Types::Common types are frozen', ); like( exception { InstanceOf->of("Foo")->coercion->add_type_coercions(HashRef, sub { bless $_, "Foo" }); }, $frozen, 'Parameterized types are frozen', ); done_testing;