It is possible to validate the values, it's just traditionally a pain in the arse, because it involves using something like Variable::Magic or returning a tied scalar.

I wrote LV to try to get around these issues, and it does indeed make writing lvalue subs pretty friendly. The primary drawback becomes speed - none of the implementations are as fast as a more traditionally written accessor.

use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name

In reply to Re^2: Is ": lvalue" attribute usefull or something to avoid? by tobyink
in thread Is ": lvalue" attribute usefull or something to avoid? by TomDLux

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