C++:
int i = 5;
i ^= printf("The initial value of i is %d\n", i)^
printf("i=i+1; // this increments i\n")^
printf("Trigger very obscure FPU bug %c",(int)((float)8.5953287712*(double)8.5953287713-'?'))/10;
printf("i has now been incremented by 1 : %d\n", i);
Output:
The initial value of i is 5
i=i+1; // this increments i
Trigger very obscure FPU bug
i has now been incremented by 1 : 6
I didn’t test other values but they’re probably OK.
I think beginners would find it a lot easier if “it’s like email” was closer to the start. But as it is you have to dig a bit before you get that particular bit of insight.
Where do you sign up? Wherever suits you. Posteo, Mailbox, Tuta etc; there are plenty of others. You aren’t limited to emailing those on your server, you can email anyone anywhere. You don’t need an account on all email servers to email people on those servers. It’s the same with Lemmy. You’re on beehaw.org, I’m on lemm.ee, and the next post down (on my screen) is on lemmy.ca.
What if you’re on Posteo but all your friends are on Mailbox? Well you can switch to Mailbox if you want but it’s not necessary. You can still email each other.
Defederation: if for example everyone on scammersunited.com is a scammer, the admins of your email server might decide to block email from that instance by default. Federation’s just a fancy word for people on Tuta to be able to email people on Runbox.