My favourite solution from … was given in the first response by tye:

Seems like he has a boiler plate reply prepared for this questions ;-). It was also his reply when I brought up that question with my very first post at PM. And it is a good solution.

Beginning with ysth's reply to my question there was some in-depth discussion of using ??{} to approach this problem. And for me this solution has some appeal:

my @split_on_char_change = $string =~ /((??{'(.)\1*'}))/g;