An introvert will lose energy rather than gain it in complex or highly active social situations, but will still emotionally feel a good connection with the person or people they're around. Someone with ASD has a much more difficult time "feeling" the positive benefits of socialization, whilst they may learn to enjoy it more from a left-brain analytical perspective. Not to say its a lack of empathy, in fact you can actively feel other's emotions in many cases, but the actual inner feelings of community and belonging may be pretty muted.