```{index} single: method_changed_in; mro function ``` ```{index} single: mro::method_changed_in; Perl function ``` # method_changed_in Force method-cache invalidation for `$class` and everything that inherits from it. ## Synopsis mro::method_changed_in($class); Normally Perl notices method installations on its own and you do not need to call this. The one documented case that escapes automatic detection is installing a constant subroutine by aliasing a readonly scalar into the stash — the trick `constant.pm` uses internally. If you build something similar, call `method_changed_in` afterwards so cached dispatches pick up the new sub. Croaks with `No such class: '...'!` if the stash for `$class` does not exist. A single argument is required; any other arity croaks with `Usage: mro::method_changed_in(classname)`.