${"$class\::Defaults"} is a symbolic reference to the Defaults hash in the respective class (Devel::Symdump here).  The % dereferences it, so the resulting hash's flattened content will initialise the anonymous hash {...} which is going to hold the instance data of the object that is created by blessing the hashref into $class.

In reply to Re: What is the use de-referencing and creating a new anonymous hash in new() and rnew() ? by almut
in thread What is the use de-referencing and creating a new anonymous hash in new() and rnew() ? by sathiya.sw

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