NAME MooX::SetOnce - write-once attributes for Moose SYNOPSIS package MyClass; use Moo; use MooX::SetOnce; has attr => ( is => 'rw', once => 1 ); DESCRIPTION MooX::SetOnce creates attributes that are not lazy and not set, but that cannot be altered once set. The logic is very simple: if you try to alter the value of an attribute with the SetOnce trait, either by accessor or writer, and the attribute has a value, it will throw an exception. If the attribute has a clearer, you may clear the attribute and set it again. If a Moose module extends or composes a module using MooX::SetOnce, MooseX::SetOnce will be loaded to provide the Moose implementation. SEE ALSO MooseX::SetOnce AUTHOR haarg - Graham Knop (cpan:HAARG) CONTRIBUTORS None so far. COPYRIGHT Copyright (c) 2013 the MooX::SetOnce "AUTHOR" and "CONTRIBUTORS" as listed above. LICENSE This library is free software and may be distributed under the same terms as perl itself.