I have always sent my son to day camps, and he has always done well. The key has been that he needs to know what to expect, and have a very specific curriculum. He does not like "play" camps. I do always put in on the forms that he is AS, and that they need to be careful with transitions and sticking to expectations. Never been a problem.
Last year we sent him to a computer camp with options for GameMaker, animation, etc. That class was probably 50% AS kids. Yes, they sometimes collaborated, but it wasn't required, the teacher student ratio was really high, and the day was about as quiet as could be imagined, with kids staring at their own computer screens all day. My son LOVED it. It's only too bad it costs about 4 times as much as any other camp.
Other favorites have been science camps, Lego camps, Shakespeare acting camp, and all things Boy Scout.
Talk to the directors of camps you think might be interesting for your child. You could be pleasantly surprised, and discover that they are totally prepared to handle an AS child.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).