initialize_moose_attr_early

This function will return "undef" if the attribute was not provided to the constructor (or if the actual attribute's value is "undef", in which case this function is useless for) or the actual (possibly coerced) value for that attribute. A typical invalid attribute passed to the constructor error will occur if the value is invalid.

  # Used in a BUILDARGS modifier
  around BUILDARGS => sub {
      my ($original_method, $class, @args) = @_;

      # Call the original method to get args HASHREF
      my $args = $class->$original_method(@args);

      if (defined(my $obj = _initialize_attr_early($class, obj => $args))) {
          # The obj attribute was coerced and valudated and is defined
          # Do something with $obj
      }

      return $args;
  };